- Email: [email protected]
Fourier transform spectroscopy of the CO Ångström bands
-_ .., -. i
;.... _ ~~_. -..
-,‘--..~7r-
-.
..-,
-__
-. -__
.-.
.
.
_-
_
:
_‘..
-
:
‘.
~..;_-___=
-..
.,::.._.
--_._...;
.._-
I-.--
5::
i
-.
‘_‘~<=;~-.-.~z;i.-:
;-
~r-r-~~~-l_r~_~_~~-~~.~~~
q&&J -pg& ijj ‘r&-j &gq ; gi.;_; ;._: ;.__:_:;:::I,... :‘. y,;;7 ;: +; : -;: , :_. :: __g:l_;y;; ..;:r:;_:. .I: ;. +y;; .+g :q if: -_._; -,; _,:5; +%&p&~$ .. Nonh_Hd.d~rtr;lam~ -- .:I.- I- ._. \ :-: .’ . _‘.: _.-__-_~_-: ;-;j -_ _:. _~<__-.. -,-:,;:’ --; _-~.~._II:~~~~,,-~~‘)’ ---:::.r:
1-z
.--
I -,_ _
‘_
-y. ;._
.-
_.
._ .;.
.. . . . . _:--.:_.
-
‘.
;.L--_i
.‘T’_
%
:... ;--
-2
_
.;.:z_-_._:-
:
_.-
--_
._.‘_C
.,;
.-.
-:-
:
-.
-:_
_.-.‘._
:
:
.,
: ;_.
.,-_: .,~.._._..
_y,,
..
-.. ;
and
-1. _, _<:: ; .:.
i;..
.,-
Obiercmobe
F&&m&de.
.’ j,-
::i ..s
.-_ -__;
.-
-__
de Meucfoti 5
_ :
_.
z.
.
.
,.-.
f-,-e
L&wax&
_ :.
ak Physique 22 Octoba
:.
AfaEruI~~r~ ci &Ogiqzu -.
19-c
in iinal form 17
-.’
Acm&ph&iquc.
~prii
B&i&&
22;:
..
Campus d-O&-. -_
:.
by ivmbiing
m
.,
.Li~
; : -. -:
__..-
_-;~--;
--,’ ._,-
_ -1 ._. -_;. : -. -:.;
:
~,
bands of the CO B’E+ - A’II perturbations of the lower A%i
~~~;md~mep~ouspcnurberyti~~rs~~~isedN~-~ceen~k\-els state are d&&d
-_I-_-
91405 Orsay. Frmr
-.
and the most accurate caw&iod
:
:
._
ktgsvii~ q&m ha\% been raorded by.Fo&i& slate are rei&si~ted_ Ad&&ma1 extra-tines are and~mole&larparame:~_forthheB
dam_
.-:
._-. :_ +~-;-.~~l--_ : ..:-_-_
:
1985
_ T-k (O-O), (0-l).
:
_z- _,,, -;
--
I.
.-c_ A&fIQT.
_,.__
17
: ._
..-.- 1 .~
-_.‘:
;i\;~~_~_*~~:.~..~~--~~~~,
-:‘;;..-l;;.,_,-:.‘::‘; ;‘:f_
-
_if-fm .-
Pk& Jcz&eiz, 92,9(,
..~
-
R&&d .-
_
&&S:
-1.
..
,k+ ‘gf _;‘..~~:S:T-_~i~i_~3~~~-~~
._:_-z;-:l.. J. _.;:** 1; ,,L,. . .
-..
: _. _.
;I
Ly.:_... ?_:.:, ._-__ ~~ :_z_.,_ ._.>.-.,
& _& & &&-F&G
.Sp~~~~&p~
-dXstroph_vsiq&
:..a
‘._
.,_
I
._.
.-.i.;:;:
‘. -.L~.r_,.,..__
TJ&$NSFOm
LJ&anmtmr
._;
I.
f _‘_.
.
FOum
;y:1,
..-I
.,- ‘.
-:_-..:~-.=_,:
.._
.
-,. __. -.
1, Introduction
_I. -_ .-. .: 2 m, and givinga-dkpersion ranging froniO.?:.td .-I 1.1 ~/mm.Curiously, t&se_bands have not been
‘-.
The B'Zt-, AtII transition of CO, which may reinvestigated under. the. most accurate conven- 1. be easily observed in the visible region, has been tional conditions: for instance by-using A. 10 m’ the subject of numerous studies since its discovery jectrograph fitted v+h a powerful grating- _ by kqstrorn in 1875 [l]_ These works were ini.~The RR data con&m the stronger (O-q,; &, = tially devoted to the ordinary: “C% molecule 0,5) and (l-u,; c;, = O-l) b&k The calibration and.extended later to the-various isotopic sp&& of their wave numbers &s achieved by using an of this molecule_ The most recent one w&under-~ iron arc and the -wave numbers of the reference lirieswere those of the tables of kaidel et al; [5] taken by F’rasad et:& [2], -and cotkernS the.rare corrected by the formulae of Edlen [6]_’ Repa. and t3C”0 isotopic. molec+e_ ..Read&s can find. an Rytel [3] gave a realistic absoIute waveriumber e_xhaustive bibliography (up -to 1983) about the -. uncertainty rariging from 0.02. to ($05 Cm+. .The Angstrom bands in this last paper_ It .should be _noticed that ah these works were carried -out- by validity of these values is suggested by the vveigthed using convention+ spectroscopy_ --: non-linear least-squares. fits perfotkxi by Fieid For the ordinary t?t?O molecule, ihe -most [7]_ In these calculations the KR.data were$tted accurate data are probably those obtained in 1970. by assuming a.tinstant experimental error-of 0.02 by, Kepa and Rytel (RR) [3] and ,by Danielah et al_ - T -It and the dimensionlerk variance- obtained ..-. = ‘. was n&y equd to u&y__ I-,- -_. ;.-~ 1 1. .- ._[4] in 1971: These data have been obtained from a plane g&&g sprktrograph h&g a fo@ length of ; 1-1-.- _ In a-more re&nt paper, dealing w&h the (l-Ga;. ' .. : 1 L_ :_.‘ .- ._._-___ ~. _. .: -_ _ vi= 4-6) bands; Danielak~ et al:~[4]~.claimed:&_ -_ .: _~_ . -_ -: -. ;-._- _‘.: .-7‘._:-I.’ ’ absolute wave-number uncertainty of 5 x 10;3-8 -_. ._ -: .-- c -: _--- 1 _ , & .-i &-&.&&; & physiqLe;:&_a& I ._-_; ~ 2__. 10T3 cm__l,_.The.specira._being reeor_ded.:by the :‘l same:spectro~pi~ method, _~&Ri:,that a.‘FeGge I-‘ .%iaicq Parr: de Gzandmo&~nivenit~ i~Iti_~Tc+~ 37+?00 -. -‘-‘F-~‘-:~.,, ..: -.:.._-.:_.; ,I~;‘_ _:;. :. =.,. :_-:= - hollow &thode was usedfor~&libratJon h&s: This :. -i -.. .+
..
-~ .
~-.
-_ ._
0301-010&&5/.S~3.30 6 E@vier Scietke Publishers B.V. -(North-Holland Rhysics~blishing Div+ion)z .__~ : :
_r
‘_
‘-1 A.1 [-
_._‘,!_-.
-.~.--. _ :
--:_ ‘_-.
. -.,_ ~. _ _-: ;z;:_’ _Ir-i_l.
is probably too optimistic for two reasonsr (I) the corresponding accuracy is ten times better than that associated with the Fe reference wave numbers c of Zaidel et al_ [5]_ (2) this uncertainty
wave-number uncertainty is of the same order of magnitude as the one obtained (2 x 10w3-4 x 10m3 cm-‘) by Luc and co-workers [8,9] in recent visibIe Fourier transform spectroscopy (ITS) measurements_ So_ this value for their absolute accuracy would be very surprising FE has been aIs0 used in the visibIe range by Amiot [lo] For the reinvestigation of the G_ Swan bands. The comparison of the oncertaintres between conventional and FT spectroscopy is now well known: For intense emission bands. free from overlapping and recorded with sufficient resolution, the FfS accuracy is almost five to ten times better than the precision obtained with grating spectroggphs. However. for weak bands, or when the spectral sensitivity of the FTS decreases (due to detectors or filters). the accuracy of both methods becomes comparable we have reinvestigated the Consequently. Angstrom bands by means of FfS. especiahy because the red part of this spectrum may be recorded under favorable conditions. providing wave numbers (for the corresponding bands) of higher accuracy than those previously obtained_ The need for a reinvestigation of the &gstrijm bands is sqgested by the study of the perturbations appearing in this spectrum_ It is well known that the (r2p)‘( a2pXc*2p) A’II state is extensiveiy perturbed by the vaIenee states belonging to the (~2p)~(a2p)‘(=*2p) configuration (ll-13]_ As all previous studies of these perturbations, via the Amzstrarn bands (for rzCr60), were published befor; the first comprehensive study undertaken by
Jenkins fl5], and by Watson [16.17]. According to these authors, the extra-lines observed for 8 G J G 17 in the (O-O) band arise from a perturbation due to the a311 state This perturb& assignment is inconsistent with Field’s results [11.12] -arid also with the reinvestigation of the A’fI state recently undertaken in ref_ [13]_ This perttuber misassignment has inam previously revised for some of these extra-lines- (for J = 9. 12 and 16) and correctly assigned to the e 3Z-(a = I)-A’Z(u = 0) spin-orbit interaction (see, for instance, table 54 of Krupenie’s monograph [lSn_ -We shall show that the remaining extra-lines (for J G 17) are also due to the same interaction. iMoreover, we shall assign new extra-lines, not previously reported, by using term-value tables coiiected in ref_ il3]_ An additional perturbation (arising from an unknown perturber) has been reported by Janjic et al. [19] in the u = 1 level (between J = 7 and 8) of the upper (&p)‘(a2p)(3sa) B’Z+ Rydberg state for ‘3C’60_ So. we shah eftamine if this perturbation occurs in the ordinary Angstrom bands. In a final step. it should be desirable to undertake a global and direct reduction of all the available data connected with the Angstrom bands (including the A-X B-X_ and B-A systems). with an appropriate_ weightd non-linear. least-squares procedure This first preliminary paper will mainly describe our spectrum, with a special emphasis on perturbations and extra-lines_ By combining the present FTS data with the A’fI term-values obtained in ref_ (13). we will deduce an accurate set of energy Ievels for the Rydberg B’Z’ state.
2. EvperimentaI
Field [‘_I]. there are some errors in this literature about this subject For instancz= we shall show that the vibrational assignments of the levels of the ,.sv+ _ state proposed by Coster and Brons [14], for the perturbers cf the A’lTf, u = 1 and 3 levels
are erroneous_ This is also the case! for the perturber
assignment
reported
by
Rosenthal
and
The spectrum of the &strem system was produced in a mixture of carbon monoxide and oxygen flowing through a fused silica tube of 30 cm length and 8 mm id_ The discharge was excited by means of a “C-type- antenna connected to a 150 W, 2450 MHz microwave generator_ The emitted radiation was collected at right angies to the tube. the oxygen pressure being kept high enough that the production of CO relative to C,.is favored_ The spectra were recorded with the Fourier
-,
_-
interfero&t& of Laboratoire Aim5 Cotton. Theresqlution limit used w$s 0.05 cm-l; the observed { _ linewidth being equal to 0.1 cm-‘. The wave-number calibration w& obtained using the Xe 3-S @i previously assi&e& have b&n obsev&i ..i&-..i& ’ line narrowed by stimulated emission which Serves (O-O) band (three in the Q branch arising frQm t&e to control the path difference of the interferom& I: 1 e3Z-, u = 1 perturbed, and otie iti the P btich ter. Because of the ‘&t&width and S/s ratio, the _; due to the d ‘4, u = 4_.inteF&idn).-As numerous wave-number absolute a&racy is better than CL01 additional perturbing- ~extra-levels, _due to these cm-’ in the spectral range (16500-25000 cm-‘) e-A and d-A interactions, have been observed via studiedthe A-+X system [13]“, further extra-lines, +t yet observed, are expected to appear in the AngstrGm bands. 3. Rest&s and -ion The (O-l) band sho\m:the maximum value for the S/N ratio_ This higher value might explain why the band head is not so well resolved as in the RI. The line assignments other bands_ Nevertheless, this band is also observed up to J = 38. The (O-l) band is also strongly The CO emission spectrum has been recorded perturbed. in this case by the a’3Z’(o = lO)-A’IT by FTS between 16500 and 25000 cm-‘. Five (u = 1) spin-orbit interaction which provides two bands belonging to the B’Z*+ A’rf transition This perturbation was previously extra-lines. appear in this range: the (O-O), (O-l), (Q-2). and (O-3) bands of the (O-u”) progression. and also 23 studied by Coster and Brons [14], who have prolines of the (l-l) band. It is well known 1201that posed an erroneous vibrational numbering for the each of these bands exhibits P, Q and R branches_ perturber (nameiy CT=. = 8)_ The correct vibrational As the A’Il state is extensively perturbed by numbering of the a’32* state ~‘iis first established ‘A, ?Z+, %-, and ‘A valence states the ‘2-. by Henberg and Hugo 1221,and the relevant ones [ll-131. the analysis of some Iiaes and extra-lines are also listed in table 1 of ref_ [12]. These vibrais not straightforward_ Our present assignments, tional assignments of perturbing levels are the only collected in tabIe 1, were carried out by using (i) ones which are consistent with the matrix elenrenr the Kepa-Rytel analysis [3], (ii) Field’s reduction method described by Field et al_ [23]_ As the rele[7] of these preceding data, and (iii) the new vant level also perturbs A’Ii( u = 0) near J = 66 reinvestigation of the A’lI state and its perturba[13], the slope-nrerhod [23] provides an additional tions reported in ref_ [13)_ test which does not support the vibrational assigns The (O-O) band, which appears as the most ment of Coster and Bion.s_ The (O-2) band includes six extra-lines, indicatperturbed band. exhibits 16 extra-lines (with 9
_-.
:
16
22172094(2oj * 22173_4s4 (14). ~ 22175_6o2(15) 22lks23(15) 2218199S(10) 221S6~ (8) 2219L320 (9)+ 2yLl57_ (7) 222o3.86o (8) 222174_056(27)* 9%" rnllrn (7) 22lS?_o55(29)15% zrxM61 (7) 2zxm76S(l7) 268 22231_S78(9) 22214_411 (9) 46% 222z7_w_ (7) Ea&l33 (9)* 30% 2223S_Sl3 (6) 22263_449(25) 15tf1 222WL275 (6) 222S3_o55(33)' ss 22261_%1 (4)
Ii
22304-494 (33) * 456 22274_131(50) +
I.
2 3 4 5. 6 7 S 9
~~
IO 11 12 13
14 15
22B6322 223OO_ISI~ 223l4_129 2232s_7SO 22344_102 2236al23
(5) (6) (5) (5) (6) (7)
31
22516.853 (7) 22394_33o (7) 22412671 (S) 22434m?(15)" 22427_So7(2o) 46% 2245o_406(Ll) 22471391 (S) 22494379(12) 225oS_O37(16)
32 33 3-z 35 36 37
22533.14441) 22557_621(15) 22584805(26) 22599AS2(17) 22626_667(22) 22653_054(2o)
(O-1, M 4 5 6
2o6912o7(14) 20695258(12) 2o7ooa9 (9)
2s 29
13
.-
.2216X169 (11) 22165_734(23)22163_938@1) 2216Z930(19) 22162642 (19) 22163.187 (13) 22164_634 (20) 22167-265 22172w4 22159JSO 22166359 22lSOS75 22171.670
.~
22274_131(50)
22181571<10)
222s7_645(11)
22188_997 (II?
223Ols27
221%_494 2X79-938 22205.982 22193.482 22205378 22219.122 22215.640 22225.657 22236.022 22246943 22258.492 22270-697
wl7_077(18)
(12, (22) * 16% (13) (12) 398 (11) (22) 26% (9) (7j (8) (sj (8) (11)
y
(11)
22300538 (25) 16% 22334.291 (19) 22321sO7 (22) 39% 22341.467 (15) 22355205 (23) 26% 22359_469 (15) 22377219 (14) 22395309(X0) 22413.947 (12) 22433210 (14) 22453.126 (2S) 22473?27 (18) 22495_060 (14) 22517264 (22) 2254255&p) 22536289 (22j 46% 22562683(25)
222S3.603 (9) 22297263 (8) 22311.768 (11) 22329372 (21) 22323x4 (31) 46% 2234u65(lS) 22358.997 (13) 22378.144 (30) 223s7399 (41) 22406561(2X) * 23s .22409z?So5)
22587504(30) 22614s4 (28) 22631.772 (63j bJ
226mm (9) -(1u zQ72Om4(30)
22429353 22453_359(31) (22) 22464239(25j 224S7_602 (24)
20676_647(&
_
22248.l27 (27)
(8)
:.
::
..
-’
22x3858(20) 222xX057 (IS) 22233.494 (21) + 22246-133 (9) *
(IO) (20) * (22) 428 (15) (24) 24% (9)
22176.891
-.z-.
.-~22179_938(22)+ 22lS5_~49 (41) 22191320 (9) _* 22l98_026(20)
_
.- : --.. - -.:
CO
Four&
.., 8 9 10 11 12 -13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 (O-2)band 1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16 17
z .
2Otil:i570.‘(8j _. AO718559(l2) 2&2ij~131-_(8) '20734.422 -(6) -20743.407--(S) 20753.115 ci> 20763519 (4)+ 20773.661. (6) 20786515 (7) 20799.096 (5) 20812498 (5) 20826443 (7) 20841216 (7) 2OS56_747_ (6) 20873.029. (6) 2OS90276. (7) 20907317 (6) 20926.207 (7) 209l4_649 (7)
_~
-- 206so517.(i6j-. : -. 206S3503~1) 20687_gy(13) -~. 2Ofi9J578(16) 20696&2(19) 20702;516(18) 20709_iq57~(9)~, 20716.300 (8) 2072!.336-(10)b'207329?3 (9) 1074242426(13) 20752.584(16) 20763519 (4)+ 20775_132<16) 2078754-$(1~) 20800.687(16) 20814.630(17) 2OS29628 (9)
20964867 (7) 2098X657 (7) 21oo81406 (9) 21004262(20)35% 21028.867 (7) 21051.887 (7) 21075593 (8) 21100.120 (8)
19241.152 (7) 192421709 (5) 19245058 (4) 19248.170 (3) 192?2104 (2) 19256.833 (2) ===-4O) -1?26&35s $2) 19275.4~~ (1) * 10283274 (I) ~19291.875 (1) 19301252 (1) 19311.412. (l) 1932Ly55 (1) 19334q8 (1) 1934$5s9 0) 19359-883 (l)
:.
%59_761(23) 20876.811(12) 208~_430(11)
: ---20746.711~ij ._‘-- .207q_493_qij. ._ .. 2076&?4?(17) -. : .20781_126(15) 20794_0@3(11). -. .~0s07571(13).-~--' 2fx32l_SSS(ll) ‘_ 20836.893(12) 20852.619 (9) 20869:074(E) : 2op250<~0) 20904_147(10) -: 20922784 (8) 2094&0(7) 20962.251~(10) 2~83.10~(13) 21004.757 (8) 21027_434<10) 21052_223(22) 21046.712(50)4953 21072_935(13) 21097&2 (7)
19237331 19234_972 19233.383 19232591, 19232591 19233_383 19234972
(4)+ (4)-f (3) * (3)+ d' (3)+ d' (3)' (4)'
~:
~-_
19237_331
(4)+
19248945 ,(4) 19254.410(11) 19260.609 (6) 19267.659 (6) 19275.452 (l)+ 19284.042 (4) 19293_3%.(4) 19303531
19240.473 (3) 19244.392 (2) 19249B94 -(4) 19254586 (2. _. 19260.S60 (2)~-19*7&m (2) --1c75_768 (2) 19284.401 (2) --~19293.827~(2)
..
..,-...
I _.
--.
(4)
19314.454 (4) 19326_147- (3) 19338.631-(4) 19351sS7 (3) 29365925 (3) 1938a747. (3) :9396_351.(3) 19412738 (3) 19429-907.(3)
-_
.. :__-.1 :I ....
..
(conriR~~mncxrpa&
.~. -.
.. : -.
_..:
20912_778(11) 20931.814(17) 20951411 (17) 20972167(16) 20!?93_446(10) 21015_491(l9) 21038.273(12) 21061_822(15) 21086_124(24)
.:: -. .
-
7~ z; --:-.; ~:-:.-’ - :;:: _‘;
-
-:
_:.
26 f7 28 29
19515529 (2) 19537_3so (2) 19561202 c_) 19545_027 (9)2&z 19576651 (2) 195%_111(13)181 1960Lz036 (2) 1%26_935 (3) I%52303 (3)
~9366.607 0)
19315_050 (2) 1932&857 19339_477 g; 19352929 (3) 19367250 (2) 19382633 (3) EMolnO8 (4) 193s9_227(14)29% 19412246 (3) iW30_~ (4) 19448839 (3)
19527_642 (3) 19549-675 (4) 195x&758 (4) 19598522 (5) 19587_021(15)29% 19617-742 (5) 19643.603 (4) 19669-679 (5)
19467955
19696-436 (5)
(3)
19486_147 .(3)
19506.483~(3)
35 36 37 38
I%78360 (3) 19305_163 (3) 1973z821 (4) 19760_651 (4) I979alal (5) 19820311(10)
lw87_9?2 (4) 19509_@+2 (4) 19523-791 (7) 19534_381(12)49% 19549_885 (5) 19573.424 (7) 19597x42 (7) 19621549 (7) 19647229 (S) 19673_668(10)
19724_059 (6) 19752.83s (5) 19775-y(13) 19785_782(11)49% 1980X916 (7) 1984aO55 (9) 19sm666 (9) 19903_363(17) 19936_626(22) 19970~626(20)
(0-3)bad 1 2 3 4 5 6 7 s 9 IO 11 I2 13 I4 IS 16 17 IS I9 20 21 22 23 M 25 26 27
17828_403(10) 17830.072 (6) l7837zsn (5) 17835B48 (4) i784Om4 (3) 1784498s (3) 178501756 (3) lf85f.401 (2) 17864_s49 (2) mrnI25 (2) i~~lc,) 17892163 (2) 17tnE925 (I) I7914514 (I) 17926_934 (I) 1794a173 (I) 17954256 (1) i7%9_lM (1) 17984_896 (I) 18mI_469 (I) 18018877 (1) 180371164 (1) 18056_I65 (I) 18076.064 (1)' 180x831 (2) 18118376 (I) i814c_949 (I)*
17824514(11) 17822270(12) 17820_856(10) 17820281 (8)d' 17820501 (6) 17821.602 (7) 17823516 (5) 17826.237 (4) 17829_796 (4) 17s35_182 (4) 17839.403 (3) 17845-452 (3) 17852327 (3) 17860_038 (3) 17868576 (3) 1787x%8 (2) 17888_150 (3) 17899.160 (2) 17911_055 (2) 17923.754 (2) i7937JO3(2) 17951.634 (3) 17966-876 (2) l798zQ8 (3) 17999-826 (2) 18017501 (3) 18036_141 (3)
17841_742(18) 17848_106(19) 17855339 (8) 17863.392 (6) 17S72.243 (6) 17881_927 (4) 17892_448 (4) 1m3_780 (3) 17915_942 (4) 17928.935. (3) 179tL753 (3) 17957394 (3) 17972860 (3) 17989_160 (3) 18006281 (2) 18024228 (3) i80429T7 (2) 18062610 (2) 18053m5 (2) 18104307 (2) 18126349 (3) 18149299 (3) 18173_053- (3) 18197_64-~(3) 182231102 (3) 18249318 (3)
30 31 3' 33 x
(canrimndm==pogc)
.
.
: _:._:y _ ,_ .-..
_ :
-.
_.,:‘__.-_~,.;;~~._r;:~_~~~
:.
.-.
_
.;.,_
-
::>
-,
A-C
.~
.-.
J. 28
-fm
2. F--q
--
:
.‘o(J)_:
. . . f_ .._ -:‘_
--_
-_, :
~--
_‘of *h, & A-+g&
s
18158_798 18187-628
29 ~.
33
:
.(7)25% (2). _ ‘-
35
36 37 38 39 40
:
:-_ :,
-: -.
I.- .z
-I
.
&
i8&7_66fI
(3)
18238584 18265309
(2) (2)
18117.151
(4)
:.- -
./z.,
:.
-.:_
-q;)
--“.:_
.,
,.
-_.
. -.:._
--
:
/_:
18333.802 ;:
18140.949 (1) + 18X4-639 (4) ~-:18189.185 (4) .~ 18214531 (4) .. _182+0_699 (4) 18267-712 (4) 18295568 (7) 18324285 (13) 18353836 (27)
..-
~. 183++?3-. lS392%4
=
;---L.:.>_T, ; .;.-_-.> -‘I-; _; ;y ._. . . . .
.)
;;__
~-z._-=’ _-;<+ ._;+_yy+l _;_,c.-L
.;_._
-
I~.
‘_.
J_:,
‘j-:L‘;~yy&& . _ .. _-:_+.-<_; ._ -- .L--‘_‘___ .._.
_I._;_.~~I,~~:~:;.li__~. :;-;-_c
y
._:
.-i8&&(5):
_m .I-- --
;-. .,:;.-
;. I’.-
-, ‘-” 18276_443..(3);
:~18076_06&(i)+.:
(2).
-
: :_ L
~8055.602--(3)
18232.733
18293.092 (2) 18320162 (2) 18349-639 (2) 18379669 (3) 184~qSO1 (3) 18147,174 (8) 18474-707(15) 13508.247(13)
34 -’
:
_‘_--p(J)
18165542 (2)
-.-
30 31 32
(l-l) 5 6 7 8 9 10 11 12 13 14 15 16 17
C Amicu
.
Table 1 (continued) ‘.
le Jib&.
. ..
: ;
y.;
..::_
:
i -.-I:;.’ r.:a.-;l;;,
:I_.
‘.--.:.-- :I]-I_.‘.
c4) (4)., -(4)
18423.661 (6) 18455.814-(Sj 18488.753 $6) 18522%7 (6)
;;:1’.
:
-- ;’
.~ ._’ : .: I;-.,;. I:.
I
-:_ __ . .._.I z ---’ ” -:.:_. ~- I‘. : - -- ... ... I :.-
-.
tid 22799.744(32) 22758.058(54) 22759324 (29) 22761239 (63) 22763.768(12) 22767.036(40)
22781.115(23) 22791.974(24) 22798.406(18) 22sO5.428(54) 22813.125C9) 22821503 (20) zz830514 (29) 22845.192(17) 22850545 (17) 22861527 (17) 22873X0 (22
22775.428(24) 227&o-622(25) 22786465 (55) 22792954 (22) 22800.181(21) 228OsLKt5(19)
*’ Errozs (in units of lo-’
an-‘) zuc reported bctm~ parentheses_A “+” indicates the coincidence of wo unresolved lina. these lines the error re&ted kxeen prostheses might be undercstimalcd A * *- shows the additional exrra-lines. ” Blended lioesw =’ Extza-lines are identified by the perccntqe ( c So) of tbcir A’ Il character_ d) Bandhead-
For
~. .. J+ahxe that we have obtained. As for the other bands, the (O-3) band is.also strongly perturbed. even. if only one. extra-line was a&signed. This extra-line arises from. thiz a’?Z?(u = 13)-A’Ti(o = 3) spinYorbit inter+xtion. For similar reasons, as indkated above, the viirational assignment of this perturbing level reported by Coster and. Brons mustbeaxt7qxed~ T -. ‘. ~: In the c&e,of pekrbations, ihe consisten&of tnqatklysis may also be tested when both P-and R lines possess extra-linei (for th+.same J-@ue)_ In ..such cases, the energy’ difference between the wave numbers of. a liae and ita k&a-line repres&s. the
_.
:
.2.
energy
separation
e parity)
of -the
between
AllI.
the lower
state
and
main live1 (of. its
extra-level_-
:for the P. and R lines should be the same, to- within the expexime+l uncertainties_ A typical example.& provided by the (O-2) b-ad-at J = 32_ Foi the P ’ .lines we get: AE = 10590 &0_019.cm-‘,-and-for the g-lines we have Ak = 10.573 -*.0.024 cm’*_ Therefore,
these
The agreement
differences
betwe&
calcuIa.zd
these experimental
valu+
for the- separation b&w-
main -tid exfra line+ - also give% an accurate Iocation of- the corresppnd__ ing : perturbing extra-level.: ms &se- x&s succesS fully +tpplied for_ ali the other sin&r -es; ._,.:--.: 5 -.
.~
. _
-1
386
AC
Ie
&L
C. Rmior / F&trier xranqorm sprcxroscop_r of he CO
.ings~riim km& I
Finally_ near the violet end of our spectrum_ 23 Iines of the- weak (1-I) band were also assigned_ The highest J-value obsetx-ed for this band was J = 17 for the Q branch_ Let us now compare once again, the accuracies andresuItsofourFTSmeasuremen KSand those obtained from con\mtidnaI grating s+zctroscopy_ As indicated above. the FIX measurements are more accurate than those of Kepa and Rytel, especial1~ for the (O-2) and (O-3) bands_ Hcxx-ever_ the (1 -I) band has been recorded uith comparable accuracies in both methods_ It should be noticed that the KR data t3]_ although not so accurate_ are more complete since they include the (O-4). (O-5) and (I-O) bands not observed in the present F’f spectra_ Moreover_ the (l-4)_ (l-5) and (l-6) bands recorded by Danielak et al_ [4] have not been recorded by FIX It is aIso well known that a weak predissociation occurs in the B’E’ state at I = 3s for c = 0 and at J = IS for c = I [ISI_ Ahhough a decrease of the intensity is observed in our spectrum for both cases_ these _ibreaking-off_ of branches are not as conclusive as the ones recently reported in ref_ 124.1 for the reinvestigation of the B’X *-X ix* transition_ and also b_v Klopotek aud Vidal j25) in their laser twestep excitation technique_ To con&de this section. ‘scf must point out that additional perturbations_ not reported above_ aIso occur in this Ff spectrum even if no extra-lines arise from their interactions_ This is. for instance_ the case for the d ‘A( c = S)-A’lT( c = 3) spin-orbit interaction_ perturbing the (O-3) band between /=ISand J= 26_ In other words. the waventimhers coliected in table 1 contain accurate information about the extensively perturbed CO A’II state_ This is p&taps the most important feature of this FT spectrum_
_& the (O-O)_ (O-1). (O-2) and (O-3) b-ands share the common B’E’( F = 0) IeveI, the corresponding data of table I may be reduced to a singje set of energy Ieveis For the B’Z+( c = 0) level. So, to each wave number appearing in tabIe 1 ue have added the corresponding lower termvahxe of the A’liI state_ recently reinvestigated in
ret [13]_ This procedure gives a numerical value For the corresponding energg level, and aIs For the - error associated with this determination by adding the two corresponding errors_ In order to be as exhaustive as possibIe. thismeth+ \vas also extended to the (U-4) and-(0-5) bands measured by Kepa and Rytel (31 from conventional spectroscopy- Therefore_ each energy ievel of the B state may be determined by numerous independent mezurements (up to 19 * in our case)_ Consequently, it becomes possible to obtain a weighted avenge value For this particular level, along with a standard error having a statistical si&ficance_ Each weight is the reciprocrd of the square of the total error. For the A’II state the absoIute error is determined for each rotational Ievel, and varies between = O-01 and = 0.05 cm-‘. According to Field-s reduction OF the KR data [7j_ a constant absoIute error of O-02 em-’ was assumed_ These results are presented in table 2. Ln addition_ these energg-levels where reduced to mokcular parameters_ coliected in table 4 below aIong with those previously obtained for comparison. by fitting the parabola I= 1, + Box - Dex’ [where _r = J( J + I)] to the term-values iisted in table 2_ with the aid of a weighted linear Ieastsquares. The rather good value For the standard deviation of the fit (SD=0_009 cm-‘) indicates that the molecular parameters are accurately determined_ Moreover. these moIecuIar parameters have aIso been deduced by fitting the (O-O) FI ijfzer listed in table 1. along uith the A’II. u = 0 levels and extra-levels reported in ref. [13]. The corresponding fitting procedure (2’ version of LSQCO) is described in ret [13]. Our values for B, and Do are in full agreement with the ones previousIy obtained by TXford and Vanderslice 1261, and also by Kepa and RyteI [3]_ The band-origin values that we have obtained from our two fits agree within 31x -However, _&ey are sIightIy Iarg+r than the one reported in ref_ 1261, although these authors did not indicate their corresponding error. The same procedure was also applied to theB ‘LT_ u = I Ievel. As we have only 23 lines recorded by FIS. we have added the more numeroUS conventional measurements previously obtained by
Table 2 .C~Bl~+(elO);ncrgyle\rl+(cm-‘) Obsawzdl’.
I
a -t
..~-
2 3 4 5 6 7 8 9 10 11 :2 13 14
:.
--:_ -Error!”
S6916.211
0.038
920_104 92?sl32 939565 955.133 974.641 999.012 $702x273 056.425 091.477 130_410 173.236 219942 270546 325.016
0.030 0.022 0.019 0.026 O-024 0.019 O_OZ O-021 O-021 0.022 0.02? 0.020 0.022 O-023 0.024 0.021
15 16
38336-a 445.555
11 IS 19 20
511-697 581.671 655317 733.230
21 22 23 24 25 26 27 28 29
814.SOS 900234 9S9.512 88082656 179-637 2sG.462 385.135 493.639 605.972
30 31
?22140 842_10?
O_OZI 0_017 O-020 O-016 0.016 O-023 0.020 O-029 0.023
32 33 34
965940 s9093.54S 224948
0.032 O-039 o_(i35
35 36 37 3s 39
MO.150 499.160 641_9+2 7SS570 93x920
0.038 O-039 0.025
_
Calculated =’
:-
--
86916.198
-
g2o_og4
: -:-
--
-927.887.. 939575 955.158 974.636
L
pears & bg 0.06 cm-’ smO&er -than the‘ o&obtained by Tilford and ~an&rslice [26]_ Let-& n&v consider the B, values~ Our value is in very close agreement with those obtained in refs. [4,24,26], these four determinations yidding an average. value: z, = X921918. (55). However, Kep& and Rytel’s value, namely -B, = 1.92164 f 0XKKlO4; seems too small compared with the other ones: We believe that this is due to their D, value which is also too small_ Our last remark wiil -concern the perturbation detected by Janjic et al_ [19] in the B’S’, ZJ= 1 level (for- ‘3C’60). Table 3 indicates that all the observed - calculated quantities are smaller than
99KOOS 87025272 056.429 091.475 130.411 173234 219942 no535 325.oG8 383362 445591
O-026 0.019 0.017
511.6% 5!31_6?1 655515
O-022 0.020 0_02I
133225 814.797 90022S 989515 8808L653 179-639 280.468 385.138 493.642 605.977
the that,
I
360.157 499.167 641.965 788546 ?38_903
0.061
abq$
the&
=l)
encqy
levels (an-‘) Error b’
CIaIcuhted c’ 89002203 009.890
3 4
021.432 036.795 056.010 079-06s 89105.958 136.684 I71zs4. 209.665
0.025 0.036
ox_421 036-794 056JM9 079_065 105.962 136.697 171269
8 9 10
data were fmally ~reduced to t&m+alues and later to mokcular parameters_ For reasons indicated in
conclude
0.050 O-035
: 7
=+th the (l-4),
describ$
may
Observed .)
15 16 17
et al_- [4] and dealing
we
S9002_180 009.890
13 14
Danidak
Thus,
: 2
11 It
(l-5), and (I-6) ban&As
errors-
within our uncertainties, no perturber crosses
Table 3 CO B”‘(c
?22138 84L120 %591S 89093528 224_%2
O-027
corresponding
251.915 298.007 347-910 401.636 459203 520573 895SS.761.
0.022 O_OlS 0.023 0.031
0.025 O-020 0.014 O-029 0.034 O-035 0.026 0.033 0.026 _
209.678 251.920 297995 347x99 401632 459.190 .520570. S9585.771
:-
*’ Weighted awage value cakutawd by combining y meas-. urcmcms of cable 1, Dan+& et at. data 141. and A*TI* term-vabxs [13J_ ” 10 of the pmading statist&l debnnination =’ ~Calculat&-from tht firled molecular constants given in cab1;4_
_
0
=.
B,
0
86916_l9S(3) *’ 869!621? (3) a?
.1_9sI30 (IO) l) lzMsOss(11)” 1_94sm~(~zs) b’ 19981~ :
S&l4_16 d) I
ss998359(~ij~’
ss99s_42 dl 8899sx21 (l3) c,
_.
1921117(IO) -’ 1921w(*4)b’ 192l90(~20)=’ 19220” 1s19o (7) =J
D,xIO" 6_729(8) ” &700(10)‘~ 6_7oo(fIs)~’ ‘6_7& _, 7_2S(32)” 6_40(+60)*’ 7-70 <&70) c, 759 736(5)”
=’ Racnt mrkc =-I c9mqx&stotbcdircctCtofthc(o-o) T;TshnasEoag~LhtheA”n.c~O~~~da~~~ kccdinwf_[13~tJ ‘acamintics(lo)arcinunilsofthe~t Rgz&m&rc~rcponedby*e authon
emphasize that further ~&tra-Iin-- h&kg Ls++l& mix&g qoe&i~&‘-in;av 1 lje- ‘d&&d in the... .-. -.Angstram b&is. *eir: wavenumber -valu&~~kay~~ be easily _predicied by.-’ ko&ii~. -&e.-giGkkni mokcular parameters of the B’Z*. state with ihe perturbing &ua_levels listed in ref. [!3]; i
: Adinowkdgem+?nt
-
-_
We wish to thank Professor R-W__ Field for providing us with his unpublished CO data, .md for a critical reading of the manuscript. The authors are grateful to Dr_ J. Verges of Laboratoire Aimi Cotton for recording the spectra on his Fourier apparatus_
” F-
lilforJ and Vandesks [26L l EK?c&qaal[24j_U~t;er(lo)~inuQiuof zIxkusipifiirf~quoteh
CJF-
the B’X+, F= 1 Iewz! ktween J = I and 17 for the ordinary ‘Q.?O moIectde- The case of ‘3C’60 will be reconsidered, directIy from the B-X transition, in ret 1241s
4_ coneh&on The reinvestigation of the hgstrijm bands by Fourier transform spectroscopy has provided a highiy accurate and con$stent set of measurements_ For the frost tin16 the astrophysicists have at their disposal accurate calibration lines for the CO mokcuIe obtained in the .hibk range by FiS_ We have aho shown that it was easy to reduce our experimental data to a self-consistent set of energy Levels For the B %* State, which are particulariy ac&rate for the u = 0 level Among the term vaIues of the higher states of co. we believe that the present set of term-values of the B state are the mostaazura te ones_ We have aIso presenteda reliable set of extraIines whase perturber assignments and mixing coefficients are consistent with Fieki-s results and with recent stu&s of ~the ATI state- We must .-
[l] AJ_ &m&n and I- ThaIen. No\a A&Rep Sot Sci upps& 3 (1875) 9. 121CV_v_ Rasad. G_I- F.Ibak‘ksd S Paddi Ftaldy. J_ Mol. Spatry_ lG4 (1984) 165. ~. 131R Kepa an& M Rycd. Aaa Pb>s Pokm A37 (1970) 585s [S] J. Danietak. R Kqa, K Gjczyk and M_ Rytd, Acta Pbys PohxL A39 0971) 29. [5] A_N_ zaidd. W-K Prok~fycv. She Raiskij. EJ. !5hreidcr. Tablicy Spckmkqkh Jinii (G_I.FL. M-w. 1962). [6] B. Edlax. J. Opt Sot Am. 43 (1953) 339_. [7] RW_ F&d. Unpublished reduction of Kepa-Ryrd‘s dame 18) P. Luc and S_ Gcrsccnkorn. Astron Asirophys 18 (1972) 209_ 191 S_ Gasta&oro. P_ Luc. A Pa-h. I Quvilfe. Asvoa Anropbys. 5s (19x) 255. [IO] CmAmkx. Anroph>x J. Sup@_ Scrs 52 (1983) 329. [III RW_ F&i. ?h D. Thesis. Harvard Uniwsity. Cambridge. USA (1971)m 1121RW_ Fm B_G_ W&e; J_D_ Simmons and SG. lilford, J_ MoL Spatry_ 44 (1972) 383_ 1131AC_ It Fkch, F_ Lamay. I Rostas. RW. FKi K-Yost&o. C Brown and E Chipman. Rcinwsigatioa of tbcCOA’Iis~&aPditspertub&ons.tokpubkbed_ [I9 D. Coma- and F. Brims. Pbysica l(l934) 634. [lSJ I R-that and FA Jenkins Proc NalL Acad_ ScL US 15 (xX29) 896_ (161 W-W_ W+on PbRev_ 410932) 378L [lq W-W_ Wauoo. Phjx &v_ 42 0932) 509_ pq P_H_Knpeoie.The* qlc&mdttimonaridr-. (NatLB&_~W&bmgto&l%&‘ .[19] I JaaFc. J_-Da&b& R_-Kcpa and U Rytd. Acfa phj& PokuLA41(l972)757: -. .~. y -- .” ~.
[221 G. Herzbag -&d i-l H&i. Can_ I Phys. 33 J1955) 757-1 1231RU’_ Field, A. Lagaqiist and I; ~cnhom. Physica Saipta : _ -. -. 14 0976) 298.
;.... _ ~~_. -..
-,‘--..~7r-
-.
..-,
-__
-. -__
.-.
.
.
_-
_
:
_‘..
-
:
‘.
~..;_-___=
-..
.,::.._.
--_._...;
.._-
I-.--
5::
i
-.
‘_‘~<=;~-.-.~z;i.-:
;-
~r-r-~~~-l_r~_~_~~-~~.~~~
q&&J -pg& ijj ‘r&-j &gq ; gi.;_; ;._: ;.__:_:;:::I,... :‘. y,;;7 ;: +; : -;: , :_. :: __g:l_;y;; ..;:r:;_:. .I: ;. +y;; .+g :q if: -_._; -,; _,:5; +%&p&~$ .. Nonh_Hd.d~rtr;lam~ -- .:I.- I- ._. \ :-: .’ . _‘.: _.-__-_~_-: ;-;j -_ _:. _~<__-.. -,-:,;:’ --; _-~.~._II:~~~~,,-~~‘)’ ---:::.r:
1-z
.--
I -,_ _
‘_
-y. ;._
.-
_.
._ .;.
.. . . . . _:--.:_.
-
‘.
;.L--_i
.‘T’_
%
:... ;--
-2
_
.;.:z_-_._:-
:
_.-
--_
._.‘_C
.,;
.-.
-:-
:
-.
-:_
_.-.‘._
:
:
.,
: ;_.
.,-_: .,~.._._..
_y,,
..
-.. ;
and
-1. _, _<:: ; .:.
i;..
.,-
Obiercmobe
F&&m&de.
.’ j,-
::i ..s
.-_ -__;
.-
-__
de Meucfoti 5
_ :
_.
z.
.
.
,.-.
f-,-e
L&wax&
_ :.
ak Physique 22 Octoba
:.
AfaEruI~~r~ ci &Ogiqzu -.
19-c
in iinal form 17
-.’
Acm&ph&iquc.
~prii
B&i&&
22;:
..
Campus d-O&-. -_
:.
by ivmbiing
m
.,
.Li~
; : -. -:
__..-
_-;~--;
--,’ ._,-
_ -1 ._. -_;. : -. -:.;
:
~,
bands of the CO B’E+ - A’II perturbations of the lower A%i
~~~;md~mep~ouspcnurberyti~~rs~~~isedN~-~ceen~k\-els state are d&&d
-_I-_-
91405 Orsay. Frmr
-.
and the most accurate caw&iod
:
:
._
ktgsvii~ q&m ha\% been raorded by.Fo&i& slate are rei&si~ted_ Ad&&ma1 extra-tines are and~mole&larparame:~_forthheB
dam_
.-:
._-. :_ +~-;-.~~l--_ : ..:-_-_
:
1985
_ T-k (O-O), (0-l).
:
_z- _,,, -;
--
I.
.-c_ A&fIQT.
_,.__
17
: ._
..-.- 1 .~
-_.‘:
;i\;~~_~_*~~:.~..~~--~~~~,
-:‘;;..-l;;.,_,-:.‘::‘; ;‘:f_
-
_if-fm .-
Pk& Jcz&eiz, 92,9(,
..~
-
R&&d .-
_
&&S:
-1.
..
,k+ ‘gf _;‘..~~:S:T-_~i~i_~3~~~-~~
._:_-z;-:l.. J. _.;:** 1; ,,L,. . .
-..
: _. _.
;I
Ly.:_... ?_:.:, ._-__ ~~ :_z_.,_ ._.>.-.,
& _& & &&-F&G
.Sp~~~~&p~
-dXstroph_vsiq&
:..a
‘._
.,_
I
._.
.-.i.;:;:
‘. -.L~.r_,.,..__
TJ&$NSFOm
LJ&anmtmr
._;
I.
f _‘_.
.
FOum
;y:1,
..-I
.,- ‘.
-:_-..:~-.=_,:
.._
.
-,. __. -.
1, Introduction
_I. -_ .-. .: 2 m, and givinga-dkpersion ranging froniO.?:.td .-I 1.1 ~/mm.Curiously, t&se_bands have not been
‘-.
The B'Zt-, AtII transition of CO, which may reinvestigated under. the. most accurate conven- 1. be easily observed in the visible region, has been tional conditions: for instance by-using A. 10 m’ the subject of numerous studies since its discovery jectrograph fitted v+h a powerful grating- _ by kqstrorn in 1875 [l]_ These works were ini.~The RR data con&m the stronger (O-q,; &, = tially devoted to the ordinary: “C% molecule 0,5) and (l-u,; c;, = O-l) b&k The calibration and.extended later to the-various isotopic sp&& of their wave numbers &s achieved by using an of this molecule_ The most recent one w&under-~ iron arc and the -wave numbers of the reference lirieswere those of the tables of kaidel et al; [5] taken by F’rasad et:& [2], -and cotkernS the.rare corrected by the formulae of Edlen [6]_’ Repa. and t3C”0 isotopic. molec+e_ ..Read&s can find. an Rytel [3] gave a realistic absoIute waveriumber e_xhaustive bibliography (up -to 1983) about the -. uncertainty rariging from 0.02. to ($05 Cm+. .The Angstrom bands in this last paper_ It .should be _noticed that ah these works were carried -out- by validity of these values is suggested by the vveigthed using convention+ spectroscopy_ --: non-linear least-squares. fits perfotkxi by Fieid For the ordinary t?t?O molecule, ihe -most [7]_ In these calculations the KR.data were$tted accurate data are probably those obtained in 1970. by assuming a.tinstant experimental error-of 0.02 by, Kepa and Rytel (RR) [3] and ,by Danielah et al_ - T -It and the dimensionlerk variance- obtained ..-. = ‘. was n&y equd to u&y__ I-,- -_. ;.-~ 1 1. .- ._[4] in 1971: These data have been obtained from a plane g&&g sprktrograph h&g a fo@ length of ; 1-1-.- _ In a-more re&nt paper, dealing w&h the (l-Ga;. ' .. : 1 L_ :_.‘ .- ._._-___ ~. _. .: -_ _ vi= 4-6) bands; Danielak~ et al:~[4]~.claimed:&_ -_ .: _~_ . -_ -: -. ;-._- _‘.: .-7‘._:-I.’ ’ absolute wave-number uncertainty of 5 x 10;3-8 -_. ._ -: .-- c -: _--- 1 _ , & .-i &-&.&&; & physiqLe;:&_a& I ._-_; ~ 2__. 10T3 cm__l,_.The.specira._being reeor_ded.:by the :‘l same:spectro~pi~ method, _~&Ri:,that a.‘FeGge I-‘ .%iaicq Parr: de Gzandmo&~nivenit~ i~Iti_~Tc+~ 37+?00 -. -‘-‘F-~‘-:~.,, ..: -.:.._-.:_.; ,I~;‘_ _:;. :. =.,. :_-:= - hollow &thode was usedfor~&libratJon h&s: This :. -i -.. .+
..
-~ .
~-.
-_ ._
0301-010&&5/.S~3.30 6 E@vier Scietke Publishers B.V. -(North-Holland Rhysics~blishing Div+ion)z .__~ : :
_r
‘_
‘-1 A.1 [-
_._‘,!_-.
-.~.--. _ :
--:_ ‘_-.
. -.,_ ~. _ _-: ;z;:_’ _Ir-i_l.
is probably too optimistic for two reasonsr (I) the corresponding accuracy is ten times better than that associated with the Fe reference wave numbers c of Zaidel et al_ [5]_ (2) this uncertainty
wave-number uncertainty is of the same order of magnitude as the one obtained (2 x 10w3-4 x 10m3 cm-‘) by Luc and co-workers [8,9] in recent visibIe Fourier transform spectroscopy (ITS) measurements_ So_ this value for their absolute accuracy would be very surprising FE has been aIs0 used in the visibIe range by Amiot [lo] For the reinvestigation of the G_ Swan bands. The comparison of the oncertaintres between conventional and FT spectroscopy is now well known: For intense emission bands. free from overlapping and recorded with sufficient resolution, the FfS accuracy is almost five to ten times better than the precision obtained with grating spectroggphs. However. for weak bands, or when the spectral sensitivity of the FTS decreases (due to detectors or filters). the accuracy of both methods becomes comparable we have reinvestigated the Consequently. Angstrom bands by means of FfS. especiahy because the red part of this spectrum may be recorded under favorable conditions. providing wave numbers (for the corresponding bands) of higher accuracy than those previously obtained_ The need for a reinvestigation of the &gstrijm bands is sqgested by the study of the perturbations appearing in this spectrum_ It is well known that the (r2p)‘( a2pXc*2p) A’II state is extensiveiy perturbed by the vaIenee states belonging to the (~2p)~(a2p)‘(=*2p) configuration (ll-13]_ As all previous studies of these perturbations, via the Amzstrarn bands (for rzCr60), were published befor; the first comprehensive study undertaken by
Jenkins fl5], and by Watson [16.17]. According to these authors, the extra-lines observed for 8 G J G 17 in the (O-O) band arise from a perturbation due to the a311 state This perturb& assignment is inconsistent with Field’s results [11.12] -arid also with the reinvestigation of the A’fI state recently undertaken in ref_ [13]_ This perttuber misassignment has inam previously revised for some of these extra-lines- (for J = 9. 12 and 16) and correctly assigned to the e 3Z-(a = I)-A’Z(u = 0) spin-orbit interaction (see, for instance, table 54 of Krupenie’s monograph [lSn_ -We shall show that the remaining extra-lines (for J G 17) are also due to the same interaction. iMoreover, we shall assign new extra-lines, not previously reported, by using term-value tables coiiected in ref_ il3]_ An additional perturbation (arising from an unknown perturber) has been reported by Janjic et al. [19] in the u = 1 level (between J = 7 and 8) of the upper (&p)‘(a2p)(3sa) B’Z+ Rydberg state for ‘3C’60_ So. we shah eftamine if this perturbation occurs in the ordinary Angstrom bands. In a final step. it should be desirable to undertake a global and direct reduction of all the available data connected with the Angstrom bands (including the A-X B-X_ and B-A systems). with an appropriate_ weightd non-linear. least-squares procedure This first preliminary paper will mainly describe our spectrum, with a special emphasis on perturbations and extra-lines_ By combining the present FTS data with the A’fI term-values obtained in ref_ (13). we will deduce an accurate set of energy Ievels for the Rydberg B’Z’ state.
2. EvperimentaI
Field [‘_I]. there are some errors in this literature about this subject For instancz= we shall show that the vibrational assignments of the levels of the ,.sv+ _ state proposed by Coster and Brons [14], for the perturbers cf the A’lTf, u = 1 and 3 levels
are erroneous_ This is also the case! for the perturber
assignment
reported
by
Rosenthal
and
The spectrum of the &strem system was produced in a mixture of carbon monoxide and oxygen flowing through a fused silica tube of 30 cm length and 8 mm id_ The discharge was excited by means of a “C-type- antenna connected to a 150 W, 2450 MHz microwave generator_ The emitted radiation was collected at right angies to the tube. the oxygen pressure being kept high enough that the production of CO relative to C,.is favored_ The spectra were recorded with the Fourier
-,
_-
interfero&t& of Laboratoire Aim5 Cotton. Theresqlution limit used w$s 0.05 cm-l; the observed { _ linewidth being equal to 0.1 cm-‘. The wave-number calibration w& obtained using the Xe 3-S @i previously assi&e& have b&n obsev&i ..i&-..i& ’ line narrowed by stimulated emission which Serves (O-O) band (three in the Q branch arising frQm t&e to control the path difference of the interferom& I: 1 e3Z-, u = 1 perturbed, and otie iti the P btich ter. Because of the ‘&t&width and S/s ratio, the _; due to the d ‘4, u = 4_.inteF&idn).-As numerous wave-number absolute a&racy is better than CL01 additional perturbing- ~extra-levels, _due to these cm-’ in the spectral range (16500-25000 cm-‘) e-A and d-A interactions, have been observed via studiedthe A-+X system [13]“, further extra-lines, +t yet observed, are expected to appear in the AngstrGm bands. 3. Rest&s and -ion The (O-l) band sho\m:the maximum value for the S/N ratio_ This higher value might explain why the band head is not so well resolved as in the RI. The line assignments other bands_ Nevertheless, this band is also observed up to J = 38. The (O-l) band is also strongly The CO emission spectrum has been recorded perturbed. in this case by the a’3Z’(o = lO)-A’IT by FTS between 16500 and 25000 cm-‘. Five (u = 1) spin-orbit interaction which provides two bands belonging to the B’Z*+ A’rf transition This perturbation was previously extra-lines. appear in this range: the (O-O), (O-l), (Q-2). and (O-3) bands of the (O-u”) progression. and also 23 studied by Coster and Brons [14], who have prolines of the (l-l) band. It is well known 1201that posed an erroneous vibrational numbering for the each of these bands exhibits P, Q and R branches_ perturber (nameiy CT=. = 8)_ The correct vibrational As the A’Il state is extensively perturbed by numbering of the a’32* state ~‘iis first established ‘A, ?Z+, %-, and ‘A valence states the ‘2-. by Henberg and Hugo 1221,and the relevant ones [ll-131. the analysis of some Iiaes and extra-lines are also listed in table 1 of ref_ [12]. These vibrais not straightforward_ Our present assignments, tional assignments of perturbing levels are the only collected in tabIe 1, were carried out by using (i) ones which are consistent with the matrix elenrenr the Kepa-Rytel analysis [3], (ii) Field’s reduction method described by Field et al_ [23]_ As the rele[7] of these preceding data, and (iii) the new vant level also perturbs A’Ii( u = 0) near J = 66 reinvestigation of the A’lI state and its perturba[13], the slope-nrerhod [23] provides an additional tions reported in ref_ [13)_ test which does not support the vibrational assigns The (O-O) band, which appears as the most ment of Coster and Bion.s_ The (O-2) band includes six extra-lines, indicatperturbed band. exhibits 16 extra-lines (with 9
_-.
:
16
22172094(2oj * 22173_4s4 (14). ~ 22175_6o2(15) 22lks23(15) 2218199S(10) 221S6~ (8) 2219L320 (9)+ 2yLl57_ (7) 222o3.86o (8) 222174_056(27)* 9%" rnllrn (7) 22lS?_o55(29)15% zrxM61 (7) 2zxm76S(l7) 268 22231_S78(9) 22214_411 (9) 46% 222z7_w_ (7) Ea&l33 (9)* 30% 2223S_Sl3 (6) 22263_449(25) 15tf1 222WL275 (6) 222S3_o55(33)' ss 22261_%1 (4)
Ii
22304-494 (33) * 456 22274_131(50) +
I.
2 3 4 5. 6 7 S 9
~~
IO 11 12 13
14 15
22B6322 223OO_ISI~ 223l4_129 2232s_7SO 22344_102 2236al23
(5) (6) (5) (5) (6) (7)
31
22516.853 (7) 22394_33o (7) 22412671 (S) 22434m?(15)" 22427_So7(2o) 46% 2245o_406(Ll) 22471391 (S) 22494379(12) 225oS_O37(16)
32 33 3-z 35 36 37
22533.14441) 22557_621(15) 22584805(26) 22599AS2(17) 22626_667(22) 22653_054(2o)
(O-1, M 4 5 6
2o6912o7(14) 20695258(12) 2o7ooa9 (9)
2s 29
13
.-
.2216X169 (11) 22165_734(23)22163_938@1) 2216Z930(19) 22162642 (19) 22163.187 (13) 22164_634 (20) 22167-265 22172w4 22159JSO 22166359 22lSOS75 22171.670
.~
22274_131(50)
22181571<10)
222s7_645(11)
22188_997 (II?
223Ols27
221%_494 2X79-938 22205.982 22193.482 22205378 22219.122 22215.640 22225.657 22236.022 22246943 22258.492 22270-697
wl7_077(18)
(12, (22) * 16% (13) (12) 398 (11) (22) 26% (9) (7j (8) (sj (8) (11)
y
(11)
22300538 (25) 16% 22334.291 (19) 22321sO7 (22) 39% 22341.467 (15) 22355205 (23) 26% 22359_469 (15) 22377219 (14) 22395309(X0) 22413.947 (12) 22433210 (14) 22453.126 (2S) 22473?27 (18) 22495_060 (14) 22517264 (22) 2254255&p) 22536289 (22j 46% 22562683(25)
222S3.603 (9) 22297263 (8) 22311.768 (11) 22329372 (21) 22323x4 (31) 46% 2234u65(lS) 22358.997 (13) 22378.144 (30) 223s7399 (41) 22406561(2X) * 23s .22409z?So5)
22587504(30) 22614s4 (28) 22631.772 (63j bJ
226mm (9) -(1u zQ72Om4(30)
22429353 22453_359(31) (22) 22464239(25j 224S7_602 (24)
20676_647(&
_
22248.l27 (27)
(8)
:.
::
..
-’
22x3858(20) 222xX057 (IS) 22233.494 (21) + 22246-133 (9) *
(IO) (20) * (22) 428 (15) (24) 24% (9)
22176.891
-.z-.
.-~22179_938(22)+ 22lS5_~49 (41) 22191320 (9) _* 22l98_026(20)
_
.- : --.. - -.:
CO
Four&
.., 8 9 10 11 12 -13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 (O-2)band 1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16 17
z .
2Otil:i570.‘(8j _. AO718559(l2) 2&2ij~131-_(8) '20734.422 -(6) -20743.407--(S) 20753.115 ci> 20763519 (4)+ 20773.661. (6) 20786515 (7) 20799.096 (5) 20812498 (5) 20826443 (7) 20841216 (7) 2OS56_747_ (6) 20873.029. (6) 2OS90276. (7) 20907317 (6) 20926.207 (7) 209l4_649 (7)
_~
-- 206so517.(i6j-. : -. 206S3503~1) 20687_gy(13) -~. 2Ofi9J578(16) 20696&2(19) 20702;516(18) 20709_iq57~(9)~, 20716.300 (8) 2072!.336-(10)b'207329?3 (9) 1074242426(13) 20752.584(16) 20763519 (4)+ 20775_132<16) 2078754-$(1~) 20800.687(16) 20814.630(17) 2OS29628 (9)
20964867 (7) 2098X657 (7) 21oo81406 (9) 21004262(20)35% 21028.867 (7) 21051.887 (7) 21075593 (8) 21100.120 (8)
19241.152 (7) 192421709 (5) 19245058 (4) 19248.170 (3) 192?2104 (2) 19256.833 (2) ===-4O) -1?26&35s $2) 19275.4~~ (1) * 10283274 (I) ~19291.875 (1) 19301252 (1) 19311.412. (l) 1932Ly55 (1) 19334q8 (1) 1934$5s9 0) 19359-883 (l)
:.
%59_761(23) 20876.811(12) 208~_430(11)
: ---20746.711~ij ._‘-- .207q_493_qij. ._ .. 2076&?4?(17) -. : .20781_126(15) 20794_0@3(11). -. .~0s07571(13).-~--' 2fx32l_SSS(ll) ‘_ 20836.893(12) 20852.619 (9) 20869:074(E) : 2op250<~0) 20904_147(10) -: 20922784 (8) 2094&0(7) 20962.251~(10) 2~83.10~(13) 21004.757 (8) 21027_434<10) 21052_223(22) 21046.712(50)4953 21072_935(13) 21097&2 (7)
19237331 19234_972 19233.383 19232591, 19232591 19233_383 19234972
(4)+ (4)-f (3) * (3)+ d' (3)+ d' (3)' (4)'
~:
~-_
19237_331
(4)+
19248945 ,(4) 19254.410(11) 19260.609 (6) 19267.659 (6) 19275.452 (l)+ 19284.042 (4) 19293_3%.(4) 19303531
19240.473 (3) 19244.392 (2) 19249B94 -(4) 19254586 (2. _. 19260.S60 (2)~-19*7&m (2) --1c75_768 (2) 19284.401 (2) --~19293.827~(2)
..
..,-...
I _.
--.
(4)
19314.454 (4) 19326_147- (3) 19338.631-(4) 19351sS7 (3) 29365925 (3) 1938a747. (3) :9396_351.(3) 19412738 (3) 19429-907.(3)
-_
.. :__-.1 :I ....
..
(conriR~~mncxrpa&
.~. -.
.. : -.
_..:
20912_778(11) 20931.814(17) 20951411 (17) 20972167(16) 20!?93_446(10) 21015_491(l9) 21038.273(12) 21061_822(15) 21086_124(24)
.:: -. .
-
7~ z; --:-.; ~:-:.-’ - :;:: _‘;
-
-:
_:.
26 f7 28 29
19515529 (2) 19537_3so (2) 19561202 c_) 19545_027 (9)2&z 19576651 (2) 195%_111(13)181 1960Lz036 (2) 1%26_935 (3) I%52303 (3)
~9366.607 0)
19315_050 (2) 1932&857 19339_477 g; 19352929 (3) 19367250 (2) 19382633 (3) EMolnO8 (4) 193s9_227(14)29% 19412246 (3) iW30_~ (4) 19448839 (3)
19527_642 (3) 19549-675 (4) 195x&758 (4) 19598522 (5) 19587_021(15)29% 19617-742 (5) 19643.603 (4) 19669-679 (5)
19467955
19696-436 (5)
(3)
19486_147 .(3)
19506.483~(3)
35 36 37 38
I%78360 (3) 19305_163 (3) 1973z821 (4) 19760_651 (4) I979alal (5) 19820311(10)
lw87_9?2 (4) 19509_@+2 (4) 19523-791 (7) 19534_381(12)49% 19549_885 (5) 19573.424 (7) 19597x42 (7) 19621549 (7) 19647229 (S) 19673_668(10)
19724_059 (6) 19752.83s (5) 19775-y(13) 19785_782(11)49% 1980X916 (7) 1984aO55 (9) 19sm666 (9) 19903_363(17) 19936_626(22) 19970~626(20)
(0-3)bad 1 2 3 4 5 6 7 s 9 IO 11 I2 13 I4 IS 16 17 IS I9 20 21 22 23 M 25 26 27
17828_403(10) 17830.072 (6) l7837zsn (5) 17835B48 (4) i784Om4 (3) 1784498s (3) 178501756 (3) lf85f.401 (2) 17864_s49 (2) mrnI25 (2) i~~lc,) 17892163 (2) 17tnE925 (I) I7914514 (I) 17926_934 (I) 1794a173 (I) 17954256 (1) i7%9_lM (1) 17984_896 (I) 18mI_469 (I) 18018877 (1) 180371164 (1) 18056_I65 (I) 18076.064 (1)' 180x831 (2) 18118376 (I) i814c_949 (I)*
17824514(11) 17822270(12) 17820_856(10) 17820281 (8)d' 17820501 (6) 17821.602 (7) 17823516 (5) 17826.237 (4) 17829_796 (4) 17s35_182 (4) 17839.403 (3) 17845-452 (3) 17852327 (3) 17860_038 (3) 17868576 (3) 1787x%8 (2) 17888_150 (3) 17899.160 (2) 17911_055 (2) 17923.754 (2) i7937JO3(2) 17951.634 (3) 17966-876 (2) l798zQ8 (3) 17999-826 (2) 18017501 (3) 18036_141 (3)
17841_742(18) 17848_106(19) 17855339 (8) 17863.392 (6) 17S72.243 (6) 17881_927 (4) 17892_448 (4) 1m3_780 (3) 17915_942 (4) 17928.935. (3) 179tL753 (3) 17957394 (3) 17972860 (3) 17989_160 (3) 18006281 (2) 18024228 (3) i80429T7 (2) 18062610 (2) 18053m5 (2) 18104307 (2) 18126349 (3) 18149299 (3) 18173_053- (3) 18197_64-~(3) 182231102 (3) 18249318 (3)
30 31 3' 33 x
(canrimndm==pogc)
.
.
: _:._:y _ ,_ .-..
_ :
-.
_.,:‘__.-_~,.;;~~._r;:~_~~~
:.
.-.
_
.;.,_
-
::>
-,
A-C
.~
.-.
J. 28
-fm
2. F--q
--
:
.‘o(J)_:
. . . f_ .._ -:‘_
--_
-_, :
~--
_‘of *h, & A-+g&
s
18158_798 18187-628
29 ~.
33
:
.(7)25% (2). _ ‘-
35
36 37 38 39 40
:
:-_ :,
-: -.
I.- .z
-I
.
&
i8&7_66fI
(3)
18238584 18265309
(2) (2)
18117.151
(4)
:.- -
./z.,
:.
-.:_
-q;)
--“.:_
.,
,.
-_.
. -.:._
--
:
/_:
18333.802 ;:
18140.949 (1) + 18X4-639 (4) ~-:18189.185 (4) .~ 18214531 (4) .. _182+0_699 (4) 18267-712 (4) 18295568 (7) 18324285 (13) 18353836 (27)
..-
~. 183++?3-. lS392%4
=
;---L.:.>_T, ; .;.-_-.> -‘I-; _; ;y ._. . . . .
.)
;;__
~-z._-=’ _-;<+ ._;+_yy+l _;_,c.-L
.;_._
-
I~.
‘_.
J_:,
‘j-:L‘;~yy&& . _ .. _-:_+.-<_; ._ -- .L--‘_‘___ .._.
_I._;_.~~I,~~:~:;.li__~. :;-;-_c
y
._:
.-i8&&(5):
_m .I-- --
;-. .,:;.-
;. I’.-
-, ‘-” 18276_443..(3);
:~18076_06&(i)+.:
(2).
-
: :_ L
~8055.602--(3)
18232.733
18293.092 (2) 18320162 (2) 18349-639 (2) 18379669 (3) 184~qSO1 (3) 18147,174 (8) 18474-707(15) 13508.247(13)
34 -’
:
_‘_--p(J)
18165542 (2)
-.-
30 31 32
(l-l) 5 6 7 8 9 10 11 12 13 14 15 16 17
C Amicu
.
Table 1 (continued) ‘.
le Jib&.
. ..
: ;
y.;
..::_
:
i -.-I:;.’ r.:a.-;l;;,
:I_.
‘.--.:.-- :I]-I_.‘.
c4) (4)., -(4)
18423.661 (6) 18455.814-(Sj 18488.753 $6) 18522%7 (6)
;;:1’.
:
-- ;’
.~ ._’ : .: I;-.,;. I:.
I
-:_ __ . .._.I z ---’ ” -:.:_. ~- I‘. : - -- ... ... I :.-
-.
tid 22799.744(32) 22758.058(54) 22759324 (29) 22761239 (63) 22763.768(12) 22767.036(40)
22781.115(23) 22791.974(24) 22798.406(18) 22sO5.428(54) 22813.125C9) 22821503 (20) zz830514 (29) 22845.192(17) 22850545 (17) 22861527 (17) 22873X0 (22
22775.428(24) 227&o-622(25) 22786465 (55) 22792954 (22) 22800.181(21) 228OsLKt5(19)
*’ Errozs (in units of lo-’
an-‘) zuc reported bctm~ parentheses_A “+” indicates the coincidence of wo unresolved lina. these lines the error re&ted kxeen prostheses might be undercstimalcd A * *- shows the additional exrra-lines. ” Blended lioesw =’ Extza-lines are identified by the perccntqe ( c So) of tbcir A’ Il character_ d) Bandhead-
For
~. .. J+ahxe that we have obtained. As for the other bands, the (O-3) band is.also strongly perturbed. even. if only one. extra-line was a&signed. This extra-line arises from. thiz a’?Z?(u = 13)-A’Ti(o = 3) spinYorbit inter+xtion. For similar reasons, as indkated above, the viirational assignment of this perturbing level reported by Coster and. Brons mustbeaxt7qxed~ T -. ‘. ~: In the c&e,of pekrbations, ihe consisten&of tnqatklysis may also be tested when both P-and R lines possess extra-linei (for th+.same J-@ue)_ In ..such cases, the energy’ difference between the wave numbers of. a liae and ita k&a-line repres&s. the
_.
:
.2.
energy
separation
e parity)
of -the
between
AllI.
the lower
state
and
main live1 (of. its
extra-level_-
:for the P. and R lines should be the same, to- within the expexime+l uncertainties_ A typical example.& provided by the (O-2) b-ad-at J = 32_ Foi the P ’ .lines we get: AE = 10590 &0_019.cm-‘,-and-for the g-lines we have Ak = 10.573 -*.0.024 cm’*_ Therefore,
these
The agreement
differences
betwe&
calcuIa.zd
these experimental
valu+
for the- separation b&w-
main -tid exfra line+ - also give% an accurate Iocation of- the corresppnd__ ing : perturbing extra-level.: ms &se- x&s succesS fully +tpplied for_ ali the other sin&r -es; ._,.:--.: 5 -.
.~
. _
-1
386
AC
Ie
&L
C. Rmior / F&trier xranqorm sprcxroscop_r of he CO
.ings~riim km& I
Finally_ near the violet end of our spectrum_ 23 Iines of the- weak (1-I) band were also assigned_ The highest J-value obsetx-ed for this band was J = 17 for the Q branch_ Let us now compare once again, the accuracies andresuItsofourFTSmeasuremen KSand those obtained from con\mtidnaI grating s+zctroscopy_ As indicated above. the FIX measurements are more accurate than those of Kepa and Rytel, especial1~ for the (O-2) and (O-3) bands_ Hcxx-ever_ the (1 -I) band has been recorded uith comparable accuracies in both methods_ It should be noticed that the KR data t3]_ although not so accurate_ are more complete since they include the (O-4). (O-5) and (I-O) bands not observed in the present F’f spectra_ Moreover_ the (l-4)_ (l-5) and (l-6) bands recorded by Danielak et al_ [4] have not been recorded by FIX It is aIso well known that a weak predissociation occurs in the B’E’ state at I = 3s for c = 0 and at J = IS for c = I [ISI_ Ahhough a decrease of the intensity is observed in our spectrum for both cases_ these _ibreaking-off_ of branches are not as conclusive as the ones recently reported in ref_ 124.1 for the reinvestigation of the B’X *-X ix* transition_ and also b_v Klopotek aud Vidal j25) in their laser twestep excitation technique_ To con&de this section. ‘scf must point out that additional perturbations_ not reported above_ aIso occur in this Ff spectrum even if no extra-lines arise from their interactions_ This is. for instance_ the case for the d ‘A( c = S)-A’lT( c = 3) spin-orbit interaction_ perturbing the (O-3) band between /=ISand J= 26_ In other words. the waventimhers coliected in table 1 contain accurate information about the extensively perturbed CO A’II state_ This is p&taps the most important feature of this FT spectrum_
_& the (O-O)_ (O-1). (O-2) and (O-3) b-ands share the common B’E’( F = 0) IeveI, the corresponding data of table I may be reduced to a singje set of energy Ieveis For the B’Z+( c = 0) level. So, to each wave number appearing in tabIe 1 ue have added the corresponding lower termvahxe of the A’liI state_ recently reinvestigated in
ret [13]_ This procedure gives a numerical value For the corresponding energg level, and aIs For the - error associated with this determination by adding the two corresponding errors_ In order to be as exhaustive as possibIe. thismeth+ \vas also extended to the (U-4) and-(0-5) bands measured by Kepa and Rytel (31 from conventional spectroscopy- Therefore_ each energy ievel of the B state may be determined by numerous independent mezurements (up to 19 * in our case)_ Consequently, it becomes possible to obtain a weighted avenge value For this particular level, along with a standard error having a statistical si&ficance_ Each weight is the reciprocrd of the square of the total error. For the A’II state the absoIute error is determined for each rotational Ievel, and varies between = O-01 and = 0.05 cm-‘. According to Field-s reduction OF the KR data [7j_ a constant absoIute error of O-02 em-’ was assumed_ These results are presented in table 2. Ln addition_ these energg-levels where reduced to mokcular parameters_ coliected in table 4 below aIong with those previously obtained for comparison. by fitting the parabola I= 1, + Box - Dex’ [where _r = J( J + I)] to the term-values iisted in table 2_ with the aid of a weighted linear Ieastsquares. The rather good value For the standard deviation of the fit (SD=0_009 cm-‘) indicates that the molecular parameters are accurately determined_ Moreover. these moIecuIar parameters have aIso been deduced by fitting the (O-O) FI ijfzer listed in table 1. along uith the A’II. u = 0 levels and extra-levels reported in ref. [13]. The corresponding fitting procedure (2’ version of LSQCO) is described in ret [13]. Our values for B, and Do are in full agreement with the ones previousIy obtained by TXford and Vanderslice 1261, and also by Kepa and RyteI [3]_ The band-origin values that we have obtained from our two fits agree within 31x -However, _&ey are sIightIy Iarg+r than the one reported in ref_ 1261, although these authors did not indicate their corresponding error. The same procedure was also applied to theB ‘LT_ u = I Ievel. As we have only 23 lines recorded by FIS. we have added the more numeroUS conventional measurements previously obtained by
Table 2 .C~Bl~+(elO);ncrgyle\rl+(cm-‘) Obsawzdl’.
I
a -t
..~-
2 3 4 5 6 7 8 9 10 11 :2 13 14
:.
--:_ -Error!”
S6916.211
0.038
920_104 92?sl32 939565 955.133 974.641 999.012 $702x273 056.425 091.477 130_410 173.236 219942 270546 325.016
0.030 0.022 0.019 0.026 O-024 0.019 O_OZ O-021 O-021 0.022 0.02? 0.020 0.022 O-023 0.024 0.021
15 16
38336-a 445.555
11 IS 19 20
511-697 581.671 655317 733.230
21 22 23 24 25 26 27 28 29
814.SOS 900234 9S9.512 88082656 179-637 2sG.462 385.135 493.639 605.972
30 31
?22140 842_10?
O_OZI 0_017 O-020 O-016 0.016 O-023 0.020 O-029 0.023
32 33 34
965940 s9093.54S 224948
0.032 O-039 o_(i35
35 36 37 3s 39
MO.150 499.160 641_9+2 7SS570 93x920
0.038 O-039 0.025
_
Calculated =’
:-
--
86916.198
-
g2o_og4
: -:-
--
-927.887.. 939575 955.158 974.636
L
pears & bg 0.06 cm-’ smO&er -than the‘ o&obtained by Tilford and ~an&rslice [26]_ Let-& n&v consider the B, values~ Our value is in very close agreement with those obtained in refs. [4,24,26], these four determinations yidding an average. value: z, = X921918. (55). However, Kep& and Rytel’s value, namely -B, = 1.92164 f 0XKKlO4; seems too small compared with the other ones: We believe that this is due to their D, value which is also too small_ Our last remark wiil -concern the perturbation detected by Janjic et al_ [19] in the B’S’, ZJ= 1 level (for- ‘3C’60). Table 3 indicates that all the observed - calculated quantities are smaller than
99KOOS 87025272 056.429 091.475 130.411 173234 219942 no535 325.oG8 383362 445591
O-026 0.019 0.017
511.6% 5!31_6?1 655515
O-022 0.020 0_02I
133225 814.797 90022S 989515 8808L653 179-639 280.468 385.138 493.642 605.977
the that,
I
360.157 499.167 641.965 788546 ?38_903
0.061
abq$
the&
=l)
encqy
levels (an-‘) Error b’
CIaIcuhted c’ 89002203 009.890
3 4
021.432 036.795 056.010 079-06s 89105.958 136.684 I71zs4. 209.665
0.025 0.036
ox_421 036-794 056JM9 079_065 105.962 136.697 171269
8 9 10
data were fmally ~reduced to t&m+alues and later to mokcular parameters_ For reasons indicated in
conclude
0.050 O-035
: 7
=+th the (l-4),
describ$
may
Observed .)
15 16 17
et al_- [4] and dealing
we
S9002_180 009.890
13 14
Danidak
Thus,
: 2
11 It
(l-5), and (I-6) ban&As
errors-
within our uncertainties, no perturber crosses
Table 3 CO B”‘(c
?22138 84L120 %591S 89093528 224_%2
O-027
corresponding
251.915 298.007 347-910 401.636 459203 520573 895SS.761.
0.022 O_OlS 0.023 0.031
0.025 O-020 0.014 O-029 0.034 O-035 0.026 0.033 0.026 _
209.678 251.920 297995 347x99 401632 459.190 .520570. S9585.771
:-
*’ Weighted awage value cakutawd by combining y meas-. urcmcms of cable 1, Dan+& et at. data 141. and A*TI* term-vabxs [13J_ ” 10 of the pmading statist&l debnnination =’ ~Calculat&-from tht firled molecular constants given in cab1;4_
_
0
=.
B,
0
86916_l9S(3) *’ 869!621? (3) a?
.1_9sI30 (IO) l) lzMsOss(11)” 1_94sm~(~zs) b’ 19981~ :
S&l4_16 d) I
ss998359(~ij~’
ss99s_42 dl 8899sx21 (l3) c,
_.
1921117(IO) -’ 1921w(*4)b’ 192l90(~20)=’ 19220” 1s19o (7) =J
D,xIO" 6_729(8) ” &700(10)‘~ 6_7oo(fIs)~’ ‘6_7& _, 7_2S(32)” 6_40(+60)*’ 7-70 <&70) c, 759 736(5)”
=’ Racnt mrkc =-I c9mqx&stotbcdircctCtofthc(o-o) T;TshnasEoag~LhtheA”n.c~O~~~da~~~ kccdinwf_[13~tJ ‘acamintics(lo)arcinunilsofthe~t Rgz&m&rc~rcponedby*e authon
emphasize that further ~&tra-Iin-- h&kg Ls++l& mix&g qoe&i~&‘-in;av 1 lje- ‘d&&d in the... .-. -.Angstram b&is. *eir: wavenumber -valu&~~kay~~ be easily _predicied by.-’ ko&ii~. -&e.-giGkkni mokcular parameters of the B’Z*. state with ihe perturbing &ua_levels listed in ref. [!3]; i
: Adinowkdgem+?nt
-
-_
We wish to thank Professor R-W__ Field for providing us with his unpublished CO data, .md for a critical reading of the manuscript. The authors are grateful to Dr_ J. Verges of Laboratoire Aimi Cotton for recording the spectra on his Fourier apparatus_
” F-
lilforJ and Vandesks [26L l EK?c&qaal[24j_U~t;er(lo)~inuQiuof zIxkusipifiirf~quoteh
CJF-
the B’X+, F= 1 Iewz! ktween J = I and 17 for the ordinary ‘Q.?O moIectde- The case of ‘3C’60 will be reconsidered, directIy from the B-X transition, in ret 1241s
4_ coneh&on The reinvestigation of the hgstrijm bands by Fourier transform spectroscopy has provided a highiy accurate and con$stent set of measurements_ For the frost tin16 the astrophysicists have at their disposal accurate calibration lines for the CO mokcuIe obtained in the .hibk range by FiS_ We have aho shown that it was easy to reduce our experimental data to a self-consistent set of energy Levels For the B %* State, which are particulariy ac&rate for the u = 0 level Among the term vaIues of the higher states of co. we believe that the present set of term-values of the B state are the mostaazura te ones_ We have aIso presenteda reliable set of extraIines whase perturber assignments and mixing coefficients are consistent with Fieki-s results and with recent stu&s of ~the ATI state- We must .-
[l] AJ_ &m&n and I- ThaIen. No\a A&Rep Sot Sci upps& 3 (1875) 9. 121CV_v_ Rasad. G_I- F.Ibak‘ksd S Paddi Ftaldy. J_ Mol. Spatry_ lG4 (1984) 165. ~. 131R Kepa an& M Rycd. Aaa Pb>s Pokm A37 (1970) 585s [S] J. Danietak. R Kqa, K Gjczyk and M_ Rytd, Acta Pbys PohxL A39 0971) 29. [5] A_N_ zaidd. W-K Prok~fycv. She Raiskij. EJ. !5hreidcr. Tablicy Spckmkqkh Jinii (G_I.FL. M-w. 1962). [6] B. Edlax. J. Opt Sot Am. 43 (1953) 339_. [7] RW_ F&d. Unpublished reduction of Kepa-Ryrd‘s dame 18) P. Luc and S_ Gcrsccnkorn. Astron Asirophys 18 (1972) 209_ 191 S_ Gasta&oro. P_ Luc. A Pa-h. I Quvilfe. Asvoa Anropbys. 5s (19x) 255. [IO] CmAmkx. Anroph>x J. Sup@_ Scrs 52 (1983) 329. [III RW_ F&i. ?h D. Thesis. Harvard Uniwsity. Cambridge. USA (1971)m 1121RW_ Fm B_G_ W&e; J_D_ Simmons and SG. lilford, J_ MoL Spatry_ 44 (1972) 383_ 1131AC_ It Fkch, F_ Lamay. I Rostas. RW. FKi K-Yost&o. C Brown and E Chipman. Rcinwsigatioa of tbcCOA’Iis~&aPditspertub&ons.tokpubkbed_ [I9 D. Coma- and F. Brims. Pbysica l(l934) 634. [lSJ I R-that and FA Jenkins Proc NalL Acad_ ScL US 15 (xX29) 896_ (161 W-W_ W+on PbRev_ 410932) 378L [lq W-W_ Wauoo. Phjx &v_ 42 0932) 509_ pq P_H_Knpeoie.The* qlc&mdttimonaridr-. (NatLB&_~W&bmgto&l%&‘ .[19] I JaaFc. J_-Da&b& R_-Kcpa and U Rytd. Acfa phj& PokuLA41(l972)757: -. .~. y -- .” ~.
[221 G. Herzbag -&d i-l H&i. Can_ I Phys. 33 J1955) 757-1 1231RU’_ Field, A. Lagaqiist and I; ~cnhom. Physica Saipta : _ -. -. 14 0976) 298.