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Conformational dependence of CH(CD)-strechings in D -glucose and some deuterated derivatives as revealed by infrared and raman spectroscopy
Gxov~~
LONGHI, 1Polit~nic~, PiazzaLeonardo
Eli
32,20133
no (zt~ly)
2
lotions
oses
E
ENTAL
of nodal
in ~~~tionin
1-s
300 IO
3000
DDE
D-GLUCOSE
cm-’
28‘00
Cd
s
3
4
3000
cm”)
2800
2550
cm
-1
2948
2958 sh
2
2919 2895 2883
QUENCI~
(Cm-‘)
a-D-Glucose-l-do
2
I.R. AND R
2
2855
1.r.
ff-D-GlUCOSe
OBSERVED
C -STR~TCHlNG
2941
a-D-Gl~cose-6,~d~
rN THE
FOR D-GLUCO~
91
2941
2 2968
28
29 2937
12 92
2947
2973
2938
~-~-G~ucose-5,6,~d~ D-Glucose-2-d,
REGION
2978
2973 2 2 2 2
2934 2910
2948
2978
2978
TV-Glucose
CH(CD)-STRJZTCHINGS
IND-GLUCOSEANDDEUTERATEDDERIVATIVES
7
TABLE II GBSER~D~~NF~QU~CX~S
(cm-If INTHE
C-D
STRETCHING ~GIONFORDE~~~D~GLUC~
PYRANOSES ~-D-G~ucose-~-~*
2196.2
a-D-Glucosf96,6-d,
2240.0 2181.0 2123.0
a-&Glucose-5,6,6-d,
2232.3 2163.8-2143.6 2113.5
D-Glucose-Z-d,
2214
a-o-Glucose-J-d,
2144.3
the band at 2944 cm-l in conjunction with other motions. 6,6-Dideuteration should drastically modify the highly coupled motions. Furthermore, in the range %X202850 cm-t, one band has disappeared in both the Raman and the i-r. spectra, snggesting a sign~c~t ~n~bution of the CH, group also in this region. The Raman band at 2993 cm-l observed for 4, with no i.r. counterpart and not reported in ref. 13, is difficult to explain. All bands which appeared in the i .r . and Raman spectra of cr-rr-glucose-.5,6,6d3 (5) are found also in those of 4, at the same frequencies, except for the two i.r. bands at 2901 and 2855 cm-l and the Raman band at 2905 cm-r, suggesting that these are the frequencies of two delocalised normal modes both cont~ning contributions from C-5-H. The i.r. and Raman spectra of D-gk%X&?-dl (6) and D-glucose3-d, (7) are difficult to interpret. In all the spectra, there is a band at 2975 cm-l, characteristic of the /3 form. The other i.r. and Raman bands are found also in the spectra of 4(o), with different intensities, thus suggesting that 6 and 7 are o as confirmed by the n.m.r. data for 7. For 6, the Raman band at 2993 cm-l and the i.r. band at 2855 cm-” are not observed. On ~ornpa~~g the spectra of 7 and 6, it is seen that the band at 2883 cm-* (i.r. and Raman) is absent from the former, while the unusual band at 2990 cm-r is present and there are differences in the relative intensities of bands in the Raman spectra. The only certain assignment is that for the signal at 2883 cm-l which is characte~stic of C-3-H. Thus, for cu-D-glucopyranose (l), C-l-H gives an isolated band at 2945 cm-*, the CH* group is associated with a band at 2945 cm-t and possibly at 2963 cm-r, another stretching of this group is present at frequencies lower than 2920 cm-r, C-5-H contributes to the band at 2901 and/or 2855 cm-r, and the band for C-3-H is at 2890 cm-l. The CH-stretching normal modes of these molecules are delocalised over
G. LONG~I,
6. ZERRi,
6. ~ATERLINI,
L. RICARD,
S. A
ration at a sin
of force constants
to characte~se e constant was k
ifferences between t e o~ent~tion
of
to
c
)-STRE~HINGS
IN D-GLUCOSE AND DEU~RA~D
be at frequencies lower thy those for the ar form, which is entrap
DERIVA~VES
to obviation.
10
6. LONGHI, G. ZERBI, 6. PA~RLINI~
\
L. RICARD, S. A
H-2 P-D-
U-D-Glucose
Fig. 4. Newman projections the c~stalline state.
of HCOH groups in cy-and
P-D-
Glucose uc~pyran~se, as viewed from 0 to C. in
force constants. ifferences
in the spectra.
TABLE III ~XPERIME~AL
FREQUENCIES
CONSTA~S’ -~ .---
FOR
ISOLATED
---_.
AND
--..-_.
Ref. .-._
c-H-ST~rCHlNGS
DIAGONAL
.-
CH gauche to l~~ep~i~
__--
--..----..---
wcf/ {cm- ‘)
fq” ~rnd~~e/~~ ocN (cm-‘)
,~ ~mdyne/~j f“n
ethanol
2Sb
2898
4.594
2957
4.789
Dioxane
176 2oc
2876 28
4.530 4.481
2962 2950
4.805 4.768
2911
4.642
Tetrahydropyran
---.-,
20c
.---.
FORCE
-
CH trans IOi~nepair
..-.-.-_______
CORRESPONDING
2831
-.-_. I.--
4.3
_--1_-_
.-______.-..___.
~Calculated according to ref. 5. 6Deduced from the i.r. spectra of selectively deuterated
molecules.
1-S
C
11
INGS IN D-GLUCOSE
U-D-Glucose
P-D-Glucose
H:5 an projections of CH*OH
u~p~anose,
as viewed from G6 to G5,
in the c~stalline state.
e intense featur
VALUES OF THE.DIAGON~
cC-3-H C-2-H
C-4-H
FORCE ~ONST~
4.530 4.5 4.550 4.550 4.702 4.730 4.750
(mdyn~~) FORTHECH-STONINGS
C-5-H C-l-H C-4-H C-2-H C-3-H C-4-H’
OFD-GLUCOSE
4.530 4.530 4. 4.730 4.730 4,799 4.799
--_-._.~-.._
- OhSC-5-H - 0.31C-6-H’ - 0.12C-6-H” ~.18C-~-~~ + 0.51C-3-H + O.lOC-5-H + 0.56C-3-H - 0.41~~6-H’
’ -
2149 __._-__
2894 2892
0.71~~3-H 0.87C-60.77C-5-H 0.76C-2-D
+ O.liXXi-H’
2901 2889 2877 2150
- 0.59C-~~”
0.85C-4-H
2964
-5-H - O.l6C-2-H -1-H - O.l4C-3-H
0.9%I-H 0.72~~3-H O.~C-2-H
- 0. 6-H’ - O.l2C-2-~ - 0 -6-H’ - 0.6SC-OH - O.l2C-3-H + -6-H” 6-H’
+ 0.14C-6-H’
-2-H -1-H - O.I4C-2-H
- O.llC-2-H - O.l2G6-H” - O.l7C-2-H 0.22(3-5-H - ~.33C-~H’ + 0.3SC-2-X + 0. IOC-2-H
- 0.25C-5-H
i_lI____
0.71C-6-H’ + 0.69C-S-H + O.l~-~H~ l.OC-2-H - O.IlC-1-H + O.l6C-4-H + O.l3C-5-H 0.76C-5-H - o.mC-6-H’ 0.76C-3-D ..-.-_. ..-....
0. -4-H 0. -6-H” 0. -3-H 0. -2-H 0. -6-H’ 0.77C-5-H 0.76C-1-D
2965
+ 0. - 0. - 0.
- O.l6C-2-H
_---
- 0.2X-2-H - 0. . llC-1-H + O.l4C4-H 0.7SC-S-H + 0.676-3-H + O.l4C-2-H 0. -6-D” - 0.37C~~’ + 0.34C-6-D” 0.66C-ED’
0.79C-OH
1.oZC-4-H
2 2 2 2 2 2 2
2892 2879 2199 2122
2959
-.--
a-D-<;iuCOS‘?-l-d1
-6-H”
(R.m.U.)-‘~ FOR a-~-GLU~~~RANOSES -.___-_-
- O.~C-~~’ - 0 + O.l2C-OH - 0. ’ + 0.17~~6-H”
AND ~G~N~E~~ORS
-2-H -2-H -3-H 0.67C-2-H t 0.77C-OH + 0.12C-4-H 0. -6-D” - 0.37C-ED’ 0.73C-5-D + 0.21C-6-D’ 0.63~~6-D’ + 0. -6-D” - 0.21C-5-D
(Cm-‘) ---.
U-~-Gi~cO~e
2199 2147 2120
2958
CALCULATED ~~QUENCIES
TABLE V
D-GLUC
ERIVA
3 d +
13
~LC~A~D
FREQUENC~S
(Cm-‘)
AND ABSOLUTE IN~NSITIES
CHARGES FOR a-D-GL~~GSES -___-u
-_-__A
X l#“),
WITH THE SETS OF
_ __.^ B
0.259
0.440
4.213 9.907 O-62$ 9.739
7.581 II.083 0.718 8.748 3.076 5544
9.423
10.724 2.975 9.418 5.429
0.420 12.240 0.750 9.8 2.910 5.540 fr.2so
0.399 9.330 5.637 0.284 5.519 119.924 4.381
0.610 14.490 5.470 0.330 4.380 6.73~ 4/m
0.227 4.146 9.867 6.208 4.532 5.227 6.013
0.400
Q.~ 7.576 0.462
.§ .2 .5 .O 2891.7 2882.0 2149.5
(t?SU2.Cd
2.779 6.732 0.735 7.583 10.836 4.3 2.736
?.4~0
11.110 4.440 5.440 4.150 3.760
.._.- .-.... _.-.-_--
-“) AND
2.49$ 5.187
4.347 7. 0. 11. 2. ‘7. 3.
t
d
----_-A
---_.~I
7
and VIII. From a comparison with Fig. 1, it appears that the intensities of the low-frequency bands have been overestimated relative to those of high frequency. When the charge values of set A were interchanged, the intensities in column B were obtained. The spectra in Fig. 6 were calculated (set B) for the CH-stretching region for the isotopic species of known anomeric composition, ascribing a Lorentzian band-shape to the transitions with 5 cm-r half-height full band-width. In this way, the calculated and experimental spectra compare fairly well even though there is no explanation of why the charges of the weaker CH’s should be higher. It is not known whether this fact is general or applies only to some CH’s. The expe~mental finding that, for D-glucose, the higher frequencies correspond to the higher intensities is contrary to what is usually observedig.
Although the calculations reported here cannot be considered as final, they give a better understanding of the vibrational spectra of D-glucose and rationalise the marked differences in the spectra of the ty and p forms. For ff-D~glucopyr~ose, the orientation of C-5-H trans to a lone pair on O-5 is defined by the 4C, conformation of the pyranose ring, which determines its characteristic frequency to be unambiguously low, at 2880 cm-r. Indeed, some modifications in the i.r. and Raman spectra are observed near this frequency for 5 but, as shown by the data in Table V, C-5-H couples with C-3-H which has a similar force constant. Moreover, the calculated C-S-D stretching frequency is at 2147 cm-i, close to the observed value at 2150 cm-l. C-3-H is almost tram to a lone pair on the closest hydroxyl oxygen (Fig. 5) and it is likely that its stretching vibration should be at -2880 cm-r. This view accords with the observed disappearance of the band at 2883 cm-r in the ir. and Raman spectra of 7 and with the correspondingly low CD-stretching observed at 2144 cm-*. Moreover, with C-3-H and C-5-H being degenerate, symmetric and antisymmetric motions at 2880 and 2900 cm-r, respectively, are obtained from the force field. This might exptain how Sdeuteration causes the disappearance of two i-r. bands (2901 and 2855 cm-r), since the band for C-3-H, now decoupled from C-S-II, is shifted towards the frequency of another CH-stretching, possibly C-2-H. In the i.r., the normal mode C-3-H -I- C-5-H (which is predicted to be more intense) is calculated at lower frequency (see Table VII and Fig. 6), in contrast to what is observed for 4. Also, in the Raman, the strongest feature was observed at 2905 cm-i and, in general, symmetric motions are expected to be more intense than antisymmetric. These facts require a reversal of the order of these two frequencies which could be accomplished by changing the sign of the interaction force constantsfi, if the diagonal force constant of Table IV is maintained. Furthermore, our force field makes it hard to interpret the 2914 cm-r band of 1,3,6,and 7, which seems to correlate to that at 2905 cm-i in 4.
1
6. LONGHI, G. ZERBI, 6. PA~RLINI,
L. RI~ARD, S. A
the relevant force constants, a
ve rise to two cou
rientation,
namely, in
*Standard localisatio~ proced~es for the oxygen done-pain obtained from a STO-36 quantum mechanical calculation on ethano13’ indicate that the lobes of Fig. 5 are se~drated by -127”, which would render the C-2-H stretching force constant h Prelimina~ calculations. fitting 4C-2the observed valne, ve results which are no better those presented here.
1NGS IN D-GLUCOSE
C
~QUENCIES 1~9), v
(Clll-*
FOR ~D~LUC~E
1
DDE
MOORS
(a.rILU.-lR),
GLUCOSE IN AQ~OUS
Eigen~ectors
AND
ABLE
I~NS~IES
SOL~ION
IA
+ 0.63G
I,
5.8
8.
4.8 0.3 5.4 6.145 6.127 8.3
4. 0. 5. 5.670 6. 5.563
12.135 1.543
.1.079 13.850
6. 0. 3. 11.343 1.518 0.893 8.499
G. LO~GHI. G. ZERRI. 6. PA~~RLI~I,
20
COMPARISON
OF OBSERVED
I.R..
AND
RAMAN,
AND
._._ I
CALCULATED
CALCULA’KdJ
II
FREQUENCIES
FOR D-GLUCOSE
FREO~~N~I~,
RESP~~IV~LY:
IV - ----
.--_-._
~~~l..U~N
L. RICARD. S. A
(COLUMNS Iv
CONTAINS
b-111 THE
CONTAIN
THE
CALCIJLATED
.-
III - .----_
I
Ii
III
IV
29 29 29 2892 Zg80
2 2 2 2893 2889 2877
C-4-H
2958 2943
C-4-H C-l-H
2894 2889
C-3-H
C-3-H C-6-H’ C-2-H - C-4C-2-H + C-4-H C-1-H C-5-H
a-D-Glucose
2914 2892 2877 (2855)
2919 28~5 83
2 2 2 2 2 2 2877
29 29 29 2891 2876 (285s)
C-2-H
~-D-~fucose-6,6-do 2993 ? 29 2941
2963 2938 Osh 1 4 2855
2978 2968
2936
2939
2924 sh 2902 (2888) (28S6)
2905
2959 2943
C-4-H C-1-H
29 2937
2994 ? 2968 2941
2 2892 2879
C-3-H - C-5-H C-2-H C-.3-H + C-S-H
2884
2891
2964 2944 2943
C-6-H“ C-I-H
2894 2892 2882
C-6-H’ - C-5-H C-2-H C-5-H - C-6-H’ aiN
I
11
2974
2982 2973
2964 2947 2938 2912 2892 2883 --
----..-
C-3--H - C-S-H C-2-H C-6-H’ C-S-H + C-3-H
AD-Glucose-5.6,6-do
2978 2973 2964
-C-6-H”
---______
- C-4-H
2947 2933
2948 2934 2910
297s 2970 2961 2941 2925
2880
2883
2877
+ C-2-H
- c-6-w
IV
2975 2970
C-3-H C-6-H’
2 2943 2942
C-4-H - C-6-H” C-6-H” -t C-4-H C-l-H
2951 2925
C-4-H C:. 1-H
2889 2877
C-6-H’ C-5-H + C-3-H
2890 2877
C-6-I-I” + C-S-H - C-S-H
21
AC
m-
22
G. LONGHI, 6. ZERBI, 6. PA~RI,IN~.
tto (Unive~it~
L. RICARD. S. ABBATE
di Tries
NCES M. STACEY.ANDD. H.WHI~~N,~ Chem. Sot..(1954) 171-176. J. Poiy~. Sci., Part C, 7 (1963) 171-185. I., AND J. L. KOENIG, ~ar~~hydr. Res.. 19 (1971) 297-310; 23 (1972) ydr. Res., 32 (1974) 79-91. Chem.,
88 (1984) 6
. Phys. Chem., 88 (
11 6. PA~R~I,
1. Chent. Sot., 108 (1 GGIANI,6. G. GALLO,AND A. retrahedrl~tl, 22 (1966) Tesi di laurea in Fisica, Univesit~ di Milano, 1983.
ELLS,Ph.D. Thesis, The Institute of Paper Cliemistry, Appleton. 14 J. H.
k-416.
1389-1397. I-3083.
Wisconsin, 1977.
SCHAC
25 J.T~v~RT, 0. SAUR, A. JANIN,ANDJ. C. I,AVALLEY, 1.Mol. Strucr., 33 (lY76) 265-272. I, J. Chem. P&s..
PUtxz, personal communication. L. JOSIEN, J. Chim. Phys.,
82 (19~5) 3534-3541.
(1968) 183~1855:
200 (1968)
LONGHI, 1Polit~nic~, PiazzaLeonardo
Eli
32,20133
no (zt~ly)
2
lotions
oses
E
ENTAL
of nodal
in ~~~tionin
1-s
300 IO
3000
DDE
D-GLUCOSE
cm-’
28‘00
Cd
s
3
4
3000
cm”)
2800
2550
cm
-1
2948
2958 sh
2
2919 2895 2883
QUENCI~
(Cm-‘)
a-D-Glucose-l-do
2
I.R. AND R
2
2855
1.r.
ff-D-GlUCOSe
OBSERVED
C -STR~TCHlNG
2941
a-D-Gl~cose-6,~d~
rN THE
FOR D-GLUCO~
91
2941
2 2968
28
29 2937
12 92
2947
2973
2938
~-~-G~ucose-5,6,~d~ D-Glucose-2-d,
REGION
2978
2973 2 2 2 2
2934 2910
2948
2978
2978
TV-Glucose
CH(CD)-STRJZTCHINGS
IND-GLUCOSEANDDEUTERATEDDERIVATIVES
7
TABLE II GBSER~D~~NF~QU~CX~S
(cm-If INTHE
C-D
STRETCHING ~GIONFORDE~~~D~GLUC~
PYRANOSES ~-D-G~ucose-~-~*
2196.2
a-D-Glucosf96,6-d,
2240.0 2181.0 2123.0
a-&Glucose-5,6,6-d,
2232.3 2163.8-2143.6 2113.5
D-Glucose-Z-d,
2214
a-o-Glucose-J-d,
2144.3
the band at 2944 cm-l in conjunction with other motions. 6,6-Dideuteration should drastically modify the highly coupled motions. Furthermore, in the range %X202850 cm-t, one band has disappeared in both the Raman and the i-r. spectra, snggesting a sign~c~t ~n~bution of the CH, group also in this region. The Raman band at 2993 cm-l observed for 4, with no i.r. counterpart and not reported in ref. 13, is difficult to explain. All bands which appeared in the i .r . and Raman spectra of cr-rr-glucose-.5,6,6d3 (5) are found also in those of 4, at the same frequencies, except for the two i.r. bands at 2901 and 2855 cm-l and the Raman band at 2905 cm-r, suggesting that these are the frequencies of two delocalised normal modes both cont~ning contributions from C-5-H. The i.r. and Raman spectra of D-gk%X&?-dl (6) and D-glucose3-d, (7) are difficult to interpret. In all the spectra, there is a band at 2975 cm-l, characteristic of the /3 form. The other i.r. and Raman bands are found also in the spectra of 4(o), with different intensities, thus suggesting that 6 and 7 are o as confirmed by the n.m.r. data for 7. For 6, the Raman band at 2993 cm-l and the i.r. band at 2855 cm-” are not observed. On ~ornpa~~g the spectra of 7 and 6, it is seen that the band at 2883 cm-* (i.r. and Raman) is absent from the former, while the unusual band at 2990 cm-r is present and there are differences in the relative intensities of bands in the Raman spectra. The only certain assignment is that for the signal at 2883 cm-l which is characte~stic of C-3-H. Thus, for cu-D-glucopyranose (l), C-l-H gives an isolated band at 2945 cm-*, the CH* group is associated with a band at 2945 cm-t and possibly at 2963 cm-r, another stretching of this group is present at frequencies lower than 2920 cm-r, C-5-H contributes to the band at 2901 and/or 2855 cm-r, and the band for C-3-H is at 2890 cm-l. The CH-stretching normal modes of these molecules are delocalised over
G. LONG~I,
6. ZERRi,
6. ~ATERLINI,
L. RICARD,
S. A
ration at a sin
of force constants
to characte~se e constant was k
ifferences between t e o~ent~tion
of
to
c
)-STRE~HINGS
IN D-GLUCOSE AND DEU~RA~D
be at frequencies lower thy those for the ar form, which is entrap
DERIVA~VES
to obviation.
10
6. LONGHI, G. ZERBI, 6. PA~RLINI~
\
L. RICARD, S. A
H-2 P-D-
U-D-Glucose
Fig. 4. Newman projections the c~stalline state.
of HCOH groups in cy-and
P-D-
Glucose uc~pyran~se, as viewed from 0 to C. in
force constants. ifferences
in the spectra.
TABLE III ~XPERIME~AL
FREQUENCIES
CONSTA~S’ -~ .---
FOR
ISOLATED
---_.
AND
--..-_.
Ref. .-._
c-H-ST~rCHlNGS
DIAGONAL
.-
CH gauche to l~~ep~i~
__--
--..----..---
wcf/ {cm- ‘)
fq” ~rnd~~e/~~ ocN (cm-‘)
,~ ~mdyne/~j f“n
ethanol
2Sb
2898
4.594
2957
4.789
Dioxane
176 2oc
2876 28
4.530 4.481
2962 2950
4.805 4.768
2911
4.642
Tetrahydropyran
---.-,
20c
.---.
FORCE
-
CH trans IOi~nepair
..-.-.-_______
CORRESPONDING
2831
-.-_. I.--
4.3
_--1_-_
.-______.-..___.
~Calculated according to ref. 5. 6Deduced from the i.r. spectra of selectively deuterated
molecules.
1-S
C
11
INGS IN D-GLUCOSE
U-D-Glucose
P-D-Glucose
H:5 an projections of CH*OH
u~p~anose,
as viewed from G6 to G5,
in the c~stalline state.
e intense featur
VALUES OF THE.DIAGON~
cC-3-H C-2-H
C-4-H
FORCE ~ONST~
4.530 4.5 4.550 4.550 4.702 4.730 4.750
(mdyn~~) FORTHECH-STONINGS
C-5-H C-l-H C-4-H C-2-H C-3-H C-4-H’
OFD-GLUCOSE
4.530 4.530 4. 4.730 4.730 4,799 4.799
--_-._.~-.._
- OhSC-5-H - 0.31C-6-H’ - 0.12C-6-H” ~.18C-~-~~ + 0.51C-3-H + O.lOC-5-H + 0.56C-3-H - 0.41~~6-H’
’ -
2149 __._-__
2894 2892
0.71~~3-H 0.87C-60.77C-5-H 0.76C-2-D
+ O.liXXi-H’
2901 2889 2877 2150
- 0.59C-~~”
0.85C-4-H
2964
-5-H - O.l6C-2-H -1-H - O.l4C-3-H
0.9%I-H 0.72~~3-H O.~C-2-H
- 0. 6-H’ - O.l2C-2-~ - 0 -6-H’ - 0.6SC-OH - O.l2C-3-H + -6-H” 6-H’
+ 0.14C-6-H’
-2-H -1-H - O.I4C-2-H
- O.llC-2-H - O.l2G6-H” - O.l7C-2-H 0.22(3-5-H - ~.33C-~H’ + 0.3SC-2-X + 0. IOC-2-H
- 0.25C-5-H
i_lI____
0.71C-6-H’ + 0.69C-S-H + O.l~-~H~ l.OC-2-H - O.IlC-1-H + O.l6C-4-H + O.l3C-5-H 0.76C-5-H - o.mC-6-H’ 0.76C-3-D ..-.-_. ..-....
0. -4-H 0. -6-H” 0. -3-H 0. -2-H 0. -6-H’ 0.77C-5-H 0.76C-1-D
2965
+ 0. - 0. - 0.
- O.l6C-2-H
_---
- 0.2X-2-H - 0. . llC-1-H + O.l4C4-H 0.7SC-S-H + 0.676-3-H + O.l4C-2-H 0. -6-D” - 0.37C~~’ + 0.34C-6-D” 0.66C-ED’
0.79C-OH
1.oZC-4-H
2 2 2 2 2 2 2
2892 2879 2199 2122
2959
-.--
a-D-<;iuCOS‘?-l-d1
-6-H”
(R.m.U.)-‘~ FOR a-~-GLU~~~RANOSES -.___-_-
- O.~C-~~’ - 0 + O.l2C-OH - 0. ’ + 0.17~~6-H”
AND ~G~N~E~~ORS
-2-H -2-H -3-H 0.67C-2-H t 0.77C-OH + 0.12C-4-H 0. -6-D” - 0.37C-ED’ 0.73C-5-D + 0.21C-6-D’ 0.63~~6-D’ + 0. -6-D” - 0.21C-5-D
(Cm-‘) ---.
U-~-Gi~cO~e
2199 2147 2120
2958
CALCULATED ~~QUENCIES
TABLE V
D-GLUC
ERIVA
3 d +
13
~LC~A~D
FREQUENC~S
(Cm-‘)
AND ABSOLUTE IN~NSITIES
CHARGES FOR a-D-GL~~GSES -___-u
-_-__A
X l#“),
WITH THE SETS OF
_ __.^ B
0.259
0.440
4.213 9.907 O-62$ 9.739
7.581 II.083 0.718 8.748 3.076 5544
9.423
10.724 2.975 9.418 5.429
0.420 12.240 0.750 9.8 2.910 5.540 fr.2so
0.399 9.330 5.637 0.284 5.519 119.924 4.381
0.610 14.490 5.470 0.330 4.380 6.73~ 4/m
0.227 4.146 9.867 6.208 4.532 5.227 6.013
0.400
Q.~ 7.576 0.462
.§ .2 .5 .O 2891.7 2882.0 2149.5
(t?SU2.Cd
2.779 6.732 0.735 7.583 10.836 4.3 2.736
?.4~0
11.110 4.440 5.440 4.150 3.760
.._.- .-.... _.-.-_--
-“) AND
2.49$ 5.187
4.347 7. 0. 11. 2. ‘7. 3.
t
d
----_-A
---_.~I
7
and VIII. From a comparison with Fig. 1, it appears that the intensities of the low-frequency bands have been overestimated relative to those of high frequency. When the charge values of set A were interchanged, the intensities in column B were obtained. The spectra in Fig. 6 were calculated (set B) for the CH-stretching region for the isotopic species of known anomeric composition, ascribing a Lorentzian band-shape to the transitions with 5 cm-r half-height full band-width. In this way, the calculated and experimental spectra compare fairly well even though there is no explanation of why the charges of the weaker CH’s should be higher. It is not known whether this fact is general or applies only to some CH’s. The expe~mental finding that, for D-glucose, the higher frequencies correspond to the higher intensities is contrary to what is usually observedig.
Although the calculations reported here cannot be considered as final, they give a better understanding of the vibrational spectra of D-glucose and rationalise the marked differences in the spectra of the ty and p forms. For ff-D~glucopyr~ose, the orientation of C-5-H trans to a lone pair on O-5 is defined by the 4C, conformation of the pyranose ring, which determines its characteristic frequency to be unambiguously low, at 2880 cm-r. Indeed, some modifications in the i.r. and Raman spectra are observed near this frequency for 5 but, as shown by the data in Table V, C-5-H couples with C-3-H which has a similar force constant. Moreover, the calculated C-S-D stretching frequency is at 2147 cm-i, close to the observed value at 2150 cm-l. C-3-H is almost tram to a lone pair on the closest hydroxyl oxygen (Fig. 5) and it is likely that its stretching vibration should be at -2880 cm-r. This view accords with the observed disappearance of the band at 2883 cm-r in the ir. and Raman spectra of 7 and with the correspondingly low CD-stretching observed at 2144 cm-*. Moreover, with C-3-H and C-5-H being degenerate, symmetric and antisymmetric motions at 2880 and 2900 cm-r, respectively, are obtained from the force field. This might exptain how Sdeuteration causes the disappearance of two i-r. bands (2901 and 2855 cm-r), since the band for C-3-H, now decoupled from C-S-II, is shifted towards the frequency of another CH-stretching, possibly C-2-H. In the i.r., the normal mode C-3-H -I- C-5-H (which is predicted to be more intense) is calculated at lower frequency (see Table VII and Fig. 6), in contrast to what is observed for 4. Also, in the Raman, the strongest feature was observed at 2905 cm-i and, in general, symmetric motions are expected to be more intense than antisymmetric. These facts require a reversal of the order of these two frequencies which could be accomplished by changing the sign of the interaction force constantsfi, if the diagonal force constant of Table IV is maintained. Furthermore, our force field makes it hard to interpret the 2914 cm-r band of 1,3,6,and 7, which seems to correlate to that at 2905 cm-i in 4.
1
6. LONGHI, G. ZERBI, 6. PA~RLINI,
L. RI~ARD, S. A
the relevant force constants, a
ve rise to two cou
rientation,
namely, in
*Standard localisatio~ proced~es for the oxygen done-pain obtained from a STO-36 quantum mechanical calculation on ethano13’ indicate that the lobes of Fig. 5 are se~drated by -127”, which would render the C-2-H stretching force constant h Prelimina~ calculations. fitting 4C-2the observed valne, ve results which are no better those presented here.
1NGS IN D-GLUCOSE
C
~QUENCIES 1~9), v
(Clll-*
FOR ~D~LUC~E
1
DDE
MOORS
(a.rILU.-lR),
GLUCOSE IN AQ~OUS
Eigen~ectors
AND
ABLE
I~NS~IES
SOL~ION
IA
+ 0.63G
I,
5.8
8.
4.8 0.3 5.4 6.145 6.127 8.3
4. 0. 5. 5.670 6. 5.563
12.135 1.543
.1.079 13.850
6. 0. 3. 11.343 1.518 0.893 8.499
G. LO~GHI. G. ZERRI. 6. PA~~RLI~I,
20
COMPARISON
OF OBSERVED
I.R..
AND
RAMAN,
AND
._._ I
CALCULATED
CALCULA’KdJ
II
FREQUENCIES
FOR D-GLUCOSE
FREO~~N~I~,
RESP~~IV~LY:
IV - ----
.--_-._
~~~l..U~N
L. RICARD. S. A
(COLUMNS Iv
CONTAINS
b-111 THE
CONTAIN
THE
CALCIJLATED
.-
III - .----_
I
Ii
III
IV
29 29 29 2892 Zg80
2 2 2 2893 2889 2877
C-4-H
2958 2943
C-4-H C-l-H
2894 2889
C-3-H
C-3-H C-6-H’ C-2-H - C-4C-2-H + C-4-H C-1-H C-5-H
a-D-Glucose
2914 2892 2877 (2855)
2919 28~5 83
2 2 2 2 2 2 2877
29 29 29 2891 2876 (285s)
C-2-H
~-D-~fucose-6,6-do 2993 ? 29 2941
2963 2938 Osh 1 4 2855
2978 2968
2936
2939
2924 sh 2902 (2888) (28S6)
2905
2959 2943
C-4-H C-1-H
29 2937
2994 ? 2968 2941
2 2892 2879
C-3-H - C-5-H C-2-H C-.3-H + C-S-H
2884
2891
2964 2944 2943
C-6-H“ C-I-H
2894 2892 2882
C-6-H’ - C-5-H C-2-H C-5-H - C-6-H’ aiN
I
11
2974
2982 2973
2964 2947 2938 2912 2892 2883 --
----..-
C-3--H - C-S-H C-2-H C-6-H’ C-S-H + C-3-H
AD-Glucose-5.6,6-do
2978 2973 2964
-C-6-H”
---______
- C-4-H
2947 2933
2948 2934 2910
297s 2970 2961 2941 2925
2880
2883
2877
+ C-2-H
- c-6-w
IV
2975 2970
C-3-H C-6-H’
2 2943 2942
C-4-H - C-6-H” C-6-H” -t C-4-H C-l-H
2951 2925
C-4-H C:. 1-H
2889 2877
C-6-H’ C-5-H + C-3-H
2890 2877
C-6-I-I” + C-S-H - C-S-H
21
AC
m-
22
G. LONGHI, 6. ZERBI, 6. PA~RI,IN~.
tto (Unive~it~
L. RICARD. S. ABBATE
di Tries
NCES M. STACEY.ANDD. H.WHI~~N,~ Chem. Sot..(1954) 171-176. J. Poiy~. Sci., Part C, 7 (1963) 171-185. I., AND J. L. KOENIG, ~ar~~hydr. Res.. 19 (1971) 297-310; 23 (1972) ydr. Res., 32 (1974) 79-91. Chem.,
88 (1984) 6
. Phys. Chem., 88 (
11 6. PA~R~I,
1. Chent. Sot., 108 (1 GGIANI,6. G. GALLO,AND A. retrahedrl~tl, 22 (1966) Tesi di laurea in Fisica, Univesit~ di Milano, 1983.
ELLS,Ph.D. Thesis, The Institute of Paper Cliemistry, Appleton. 14 J. H.
k-416.
1389-1397. I-3083.
Wisconsin, 1977.
SCHAC
25 J.T~v~RT, 0. SAUR, A. JANIN,ANDJ. C. I,AVALLEY, 1.Mol. Strucr., 33 (lY76) 265-272. I, J. Chem. P&s..
PUtxz, personal communication. L. JOSIEN, J. Chim. Phys.,
82 (19~5) 3534-3541.
(1968) 183~1855:
200 (1968)