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Electrophysical properties and ultraviolet spectra of some polyazopolyarenes
V. G. KOSTROVSKIIet a/.
1936
6. Z.A. KOCHNOVA and M. F. SOROK1N, Lakokras. mat. i ikh primenenie, No. 6, 78, 1966 7. lYI.F. SOROKIN, Z. A. KOCHNOVA and B. N. GRAFKIN, Lakrokras. mat. i ikh primenenie, No. 4, 1, 1967 8. V. A. KARGIN and G. L. SLONIMSKH, Kratkie ocherki po fiziko-khimii polimerev (Short Essays on the Physical Chemistry of Polymers). Izd. "Khimiya", 1967 9. V. A. KARGIN, Uspekhi khimii 35: 1006, 1966 10. V. Ye. BASIN, V. I. YELINEK, T. N. GANINA and L. M. KORSUNSKII, Programma VII konferentsii po elektronnoi mikroscopii (Programme of the Seventh Conference on Electron Microscopy). Kiev, 1969 11. K. KUTSUYA, J. Polymer Sci. B3: 403, 1965 12. B. J. SPIT, Polymer 4: 109, 1963 13. M. R. KISELEV, E. N. YEVKO and V. M. LUKYANOVICH, Zavod. lab. 32: 201, 1966
ELECTROPHYSICAL
PROPERTIES
OF SOME
AND
ULTRAVIOLET
SPECTRA
POLYAZOPOLYARENES*
V. G. KOSTROVSKII, YE. D. •ITMAN, A. I. SHPON'KO, V. G. ~L~ZUR, IV[. P. TERI~UGOVA a n d I. L. KOTLYAREVSKII
Institute of Chemical Kinetics aud Combustion, Siberian Branch of the U.S.S.R. Academy of Sciences
(Received 23 January 1970) THIS p a p e r presents m e a s u r e m e n t s of the ultraviolet spectra a n d o f the t e m p e r a t u r e d e p e n d e n c e o f the electrical c o n d u c t i v i t y o f p o l y a z o p o l y a r e n e s with alkoxy- or dialkyl(arylalkyl)amino.groups as s u b s t i t u e n t s in t h e repeating unit o f t h e p o l y m e r chain, a n d containing sulphur atoms, nitrogen atoms or aliphatic bridges between the benzene nuclei. T h e p r e p a r a t i o n and properties of the polymers are described in references [1] a n d [2]. T h e electrical conductivities were m e a s u r e d b y the m e t h o d of reference [3]. The results are p r e s e n t e d in Table 1 a n d Fig. 1. T h e t e m p e r a t u r e d e p e n d e n c e of the specific electrical c o n d u c t i v i t y o f these p o l y m e r s is expressed b y the e q u a t i o n log a--~log aoE/]cT. T h e relationship bet w e e n log a 0 a n d E is linear (compensation effect, Fig. 1). The slope of the line (A log ao/AE~ l/To) corresponds to the t e m p e r a t u r e 200 °, a t which t h e specific electrical conductivities o f all the polymers are closest to one another, lying within t h e limits of 3 × 10 -11-+1 ohm-1, cm-1. T h e c o n d u c t l• w•t y asp 2o is 10-~e± a o h m -1. cm -~. I t is shown in reference [4] t h a t the position of a point on the straight line representing t h e compensation effect is d e p e n d e n t on s t r u c t u r a l features o f the p o l y m e r t h a t d e t e r m i n e the packing density of the molecules. We were unable t o e x t e n d this relationship to the present series of polymers. * Vysokomol. soyed. A13: No. 8, 1721-1726, 1971.
Electrophysical properties of some polyazopolyarenes
1937
The ultraviolet spectra of some of the polymers were recorded, in order to establish the system of electronic states in polyazopolyarenes. The spectra were recorded in solution in diethyl ether, dioxan and dimethylformamide, in a Cary-15 spectrophotometer. The polymers are only partially soluble and obviously the
1 .Oo/
E,eV
o
~ 0 ~"
000 0
-o
o
0 0 O~
o
t
~
,
o
I
,
i
I
e
I
1
I
tOgao
FIo. 1. Relationship between the pre-exponential factor and the energy of activation for electrical conductivity of polyazopo]yarenes.
spectra can be attributed only to the low-molecular fractions.* The absorption spectra, and the energy level schemes and the transitions between them are presented in Fig. 2 and Table 2. In Table 2 ¢ and ~* are the ground state and excited energy levels of the ~electrons of the benzene nuclei respectively, r l , ~2 and ~ , ~e* the energy levels of the ~-eleetrons of the - - N ~ I q bond, and n= and n, the split levels of the unshared pairs of the nitrogen atoms. A similar assignment of bands is made in reference [5] for azobenzene. The spectra of polymers I, I I and X X I X are similar to the spectrum of azobenzene (Fig. 2a), b u t in addition to the bands noted in reference [5] there is a band at 200 m/l. The fact that this was not observed b y the authors of reference [5] is evidently explained b y the fact-that the wavelength range of their apparatus did not extend below 210 m/l. When the hydrogen atoms in the para-position of azobenzene are replaced b y carbon atoms in these polymers a small longwave shift of all the bands occurs. The band in the 440 m/l region corresponds to the n~,s->~* transition. The broadness of this band is explained b y splitting of the n levels. According to reference [5] the band at 340 m# corresponds to the ~1->~* (longwave e d g e ) a n d ~i->~* (shortwave edge) transitions. The ¢ 2 - ~ * and ~ - > ~ * The molecular weight of the soluble fractions of some of the polymers, determined by the inverse ebullioscopic method, corresponds to m =4-5 (Table 1).
V . G. KOSTROVSKII
1938
et aL
T A B L E 1. E L E C T R I C A L OONDUOTIVITIES OF P O L Y A Z O P O L Y A R E N E S
PolymerNo.
Chemical f o r m u l a
E, eV logao
I
1-39 I
+, •
II
CHs
--
4.6
a;:~ 3.5X I 0 - '
I
1"0 X 10 -la ~H a
H , _- ~ / _- - N _ _,%_// / = \ _ _ S ~ - ~ ' ~%_.//-- FI_Y-H2 -]~-
III
H,--(--N~\
IV
- t-
H
'%_//--
9"0 X 10 - i s
S0,--/=\--N--~--H,
"%_//
/ = N--/=~--N
=
4"0 X 10 -1~
-]~-
-/~\-N
= \ =
H 1'0 X 10 - l e
V H--/
N
/=\
N
z l= ~ J
VI
\
~,--// "%--//
\
c,/
H -/-
H
IX
-/--N--Y=\--/=\--\
% / - - // "%- - // \
• i H.C.0 H,- /
-|-t,
X
\-
% // ",~ //
--I-
- H,
--i-
4"1 X 10 - i s H,
6"2 X 10 -re
0-o-0,., /o /oc5, 1.6 X 10 - i s
5,=
H,=
=
5.oo~--~/
N--(~--N~
XII
o,
XIII
+ -- I,g ,
H2--
/~
,-N
~.
\//\0-n-C,H,
\
0:
XV XVI *
-\
--~ - / = \ - 7 = \ - ~ - \ -
o~5,
XlV
3.5 X 10 -17
0C.H. /m
5,co\ XI
H,
/m
"OCH.
'-I--
5"0 × 10 -~1 /m
-l-
%--(/ %--// / ",,
H,CO"
3"9 X 10 - i s
/m
-|
\c~
N--/=\--/=\--~-
'-I-"
VIII
I
n-CsH~,
'-/-
VII
/~\--N--\=H
~J
"
0 n 0,5.
H~
]2' 1.9 X 10 -~8
1.7 X 10 - ~
)?.
)?,
2'0 × 10 -15
1"0 X 10 -1~
1"1 X 10 -15
* The molecular weights of polymers XVI, XVII a n d X V I I I were determined b y analysis of their hydrochlorides [1].
1939
Eleetrophysical properties of some polyazopdlyarenes T~B~.E 1 (cont.) Polymer No.
Chemical f o r m u l a
"("
XVlI *
E , eV loga0
)2
~
0"83
1"0 × 10 -x4
0"60
7"0 X 10 -14
0"64
5"1 × 10 -la
XX
1.04
5"3 × 10 -x~
XXI
0"79
1"0 X 10 -x5
XXlI
0"87
1'6 × 10 -xs
0"87
2-0 X 10-1=
1"78
5"1 × 10 -I1
1"58
1"0 X 10 -21
0"66
2.5 × 10 -is
0"67
4"2 X 10 -16
0"57
1"0 X 10 -x4
1"17
5"7 × I0 -s2
0"65
5"3 × 10 -15
1"4
6"0 × 1 0 - "
0"74
4"8 X 10 -15
~,-/-~J=\
~
"~
XVlII * O-n-Ca]~ ?
19--21
)
H = /=~--/:\--N(CH
XlX
o.-.,. . .
II ~
I
XXIII
L
\//%
\
~\
"~--Z/m
~Hs~ /
H,- [-- N ~ \ - - ~ ' ~ - - - N - XXIV
- l-
\ H,C0
XXV
)--Y
"~--'~
-
0OH,
N- / = \ --/---~\--N --'~ -- H, ~ - - ~ "~--~ -)-
/m
/
?-Y
\ H,C0 XXVI
[
/--'-. /
\//\
/
0CHs HsC
H, -- ./ = ~ _ /..~_~/ = . x _~_~/ ~\_~
~sCO/
= ~ _ _~_-/ /=\_~
\OCH.
CHs
/m
-_ ,\ - _ )~
H,
XXVII
\ a.co XXVIII
'-I-
ooa, --~_Y
",~_//-- \0CH,
k HsC0
XXIX XXX
~ ~ / ~ a , ~T= /--\
,~ // ,, :/--~-~-H. --/~~.--.-(- ~-~,,=>,,--c~. ,--~=,-3
'-t-
--'~_// %,_//
-/~
~,
).
~ \ ~ = \ ~ - / / - - N--\--H ' ---/-~T /--~__~/ -/' XXXI XXXII
k
H*C /
\CH, /~
V. G. KOSTROVSEIIe~ al.
1940
transitions should lie in the region of 280 m/~, but are prohibited and therefore their intensity is low. The authors of reference [5] ambiguously assign the band a t 2 4 0 m/~, either to the ~ - ~ 5 " transition or to a possible ~5->u~ transition. Since in contrast to those authors we were able to record the strong band in t h e 200 nap region, which is assigned to ~ - ~ 5 . transitions in benzene, the only possible assignment of the band at 240 m/~ is to the ¢ ->u* transition. D
I-0
))
,.~
-
d
,Z,J
IV , ~
I:
-.~
LI ', ,,/I, 0"5
1"0 I
0"5
I
~,;
1"-'7
I
I I"~---r"
I
I
I
I
1"0
I
)
I
i
T'~-t--
f 2
0"5 /\
//~\
\. I
P
300
I
f
J
I "~'~
500
J
[
300
J
I
J
5gg
---
A, m~
Fie. 2. Ultraviolet spectra of polyazopolyarenes: a: 1 - - I , 2--11, 3 - - X X I X ; b: 1 - - X X X a , 2 - - X X X ; 3 - - X X X b ; c: 1 - - X X X I , 2 - - V I I ; d - - I I I ; e: 1 - - X X X I I , 2--V; f - - f r a c t i o n of polymer X X I soluble in ether (1), in dioxan (2) and in dimetbylformamide (3).
No band shifts occur in the spectra of 4,4'-diaminoazodiphenyl (the product of oxidative dimerization of benzidine) (XXX), of polymer XXXa, obtained by oxidative polycondensation of dimer X X X , or of polymer XXXb, obtained from benzidine (Fig. 2b). This indicates that interactions of electrons in these conjugated systems die out almost completely at a distance of two monomer units. The only noteworthy change in the spectra of X X X , X X X a and X X X b is broadening of the bands on passing from the dimer to the polymers. Qualitatively there is no difference between the energy-level schemes for azobenzene and polymer XXXb. In the latter, because of the effect of the additional benzene nucleus oh the azo-group, the energy levels of its n-electrons are closer together than in
Eleetrophysical properties of some polyazopolyarenes
1941
TABLE 2. FREQUElqCIES OF THE TRANSITIONSIN THE ULTR/kVIOLETSPECTR~- OF POLYAZOPOLYARENES
I II XXIX XXX a,b XXXI VII III J-transition XXXII V
195 195 195 205 211 218 205 Strong 195 195
240 235 237 263 264 268 255 Strong ~255" ~0255"
335 338 340 410 420 425 385 Strong 440 450
340 343 344 415 425 435 395 Strong 450 500
~ 280 280 280 300 ~ 300 ~ 300 ~ 300 Weak N315
J-transition
Strong
Weak
Strong
Strong
Weak
* For polymersXXXII
and V- •
~315
440 440 ~ 440 ~ 500 ~ 500 ~ 530 ~480 Weak ~ 530 525 Strong Weak
-->~a.
p o l y m e r s I a n d II. On t h e basis o f the conclusions o f reference [5] it m a y be concluded t h a t t h e ~ level does n o t undergo a large shift. T h e n t h e b a n d a t 417 m/~ will obviously correspond to t h e ~1->~* (longwave edge) a n d 4 - > ~ (shortwave edge) transitions, a n d t h e b a n d at 263 m/~ t o t h e 4 - > ~ transition. I n t r o d u c t i o n of - - C H 3 a n d --C1 as s u b s t i t u e n t s in t h e ortho-position to t h e azo-group (polymers V I I a n d X X X I ) causes a longwave shift o f the b a n d in t h e 200 m~ region (Fig. 2c). This is explained b y t h e resonance effect of t h e substit u e n t on t h e benzene nucleus [6]. This shift is one of the a r g u m e n t s in f a v o u r of assignment of t h e 200 m/~ b a n d to t h e 4 ->4* transition. S u b s t i t u t i o n o f sulphur as a bridging a t o m (polymer I I I ) in place of an alip h a t i c group, has little effect on t h e levels of either the benzene nuclei or the azo-groups (Fig. 2d). T h e s p e c t r u m of p o l y m e r X X X I I indicates t h e presence o f conjugation (Fig. 2e). H e r e t h e r e is no shift in t h e ~5 and 4 " levels of the benzene nuclei in comparison w i t h those levels in p o l y m e r s I a n d II. T h e strong b a n d a t 450 m/~ corresponds to transitions of the s y s t e m of levels ~ - ~ and 4 - > ~ , shifted to the longwave region as a result of conjugation. T h e b a n d corresponding to t h e n~,s --->~ t r a n s i t i o n should a p p e a r in the same region (530 m~). I n fact in the s p e c t r u m of p o l y m e r V the levels of t h e u n s h a r e d electron pairs o f t h e nitrogen in the y - - N = N - - a n d N H bonds are s o m e w h a t different as a result of increased p r o b a b i l i t y of the n~,s ->~* transition, a n d t h e r e is a strong d o u b l e t a t 500-525 m/l. I n o t h e r respects t h e spectra of polymers X X X I I a n d V are t h e same. F r o m t h e spectra of t h e various fractions of p o l y m e r X X I (Fig. 2f, fraction 1, which is soluble in ether, consists m a i n l y o f the dimer, fraction 2, soluble in dio x a n and fraction 3, soluble in d i m e t h y l f o r m a m i d e ) r e c o r d e d in d i m e t h y l f o r m a mide, it is seen t h a t as the chain length increases all t h e bands b e c o m e broader,
1942
K . A . A~DRIA_N'OVeta[.
as in the case of lJolymer XXXb, and the spectrum loses its structure. This broadening of the bands can be explained by scattering of the light on the long polymer molecules. CONCLUSIONS
(1) The electrical conductivity of twenty eight polyazopolyarenes has been measured. (2) The electronic transitions in some of the polyazopolyarenes have been established. Translated by E. O. PK~y~PS REFERENCES 1. M. P. TERPUGOVA, V. G. MAZUR, I. L. KOTLYAREVSKH~ N. A. LAPSHINSKAYA
and Z. P. TROTSENKO, Izv. Akad. Nauk SSSR, ser. khim., 2351, 1970 2. M. P. TERPUGOVA, I. L. KOTLYAREVSKH and E. K. ANDRIEVSKAYA, Izv. Akad. Nauk SSSR, set. khim., 1854, 1964 3. V. G. KOSTROVSKII, I. L. KOTLYAREVSKII, A. S. ZANINA and S. I. SHERGINA, Vysokomol. soyed. Bl1: 334, 1969 (Not translated in Polymer Sei. U.S.S.R.) 4. I. L. KOTLYAREVSKII, M. P. TERPUGOVA, N. M. BAZHIN and M. F. BASHKIROV, Izv. Akad. Nauk SSSR, set. khim., 1620, 1966 5. H. H. JAFFE, S. I. YEH and R. W. GARDNER, J. Mol. Spectroscopy 2: 120, 1958; H. H. JAFFE and M. ORCHIN, Theory and Application of Ultraviolet Spectroscopy, pp. 278, 280, New York-London, 1962 6. W. WEST (Ed.), Primenenie spektroskopii v khimii (Application of Spectroscopy in Chemistry). Foreign Literature Publishing House, 1959 (Russian translation)
THE VARIATION IN THE VISCOSITY AND MOLECULAR-WEIGHT PARAMETERS IN LOW-TEMPERATURE DEGRADATION OF POLYDIMETHYLSILOXANE P R E P A R E D WITH INITIATORS OF DIFFERENT STRUCTURE* K . A. ANDRIANOV, S. A. PAVLOVA, I. I. TVERDOKHLEBOVA, N. V. PERTSOVA a n d I. V. ZHURAVLEVA Institute of Hetero-organic Compounds, U.S.S.R. Academy of Sciences
(Received 27 January 1970) POLYDIMETHYLSILOXANE o b t a i n e d b y p o l y m e r i z a t i o n w i t h alkaline i n i t i a t o r s h a s b e e n t h e s u b j e c t of s t u d y of a n u m b e r of a u t h o r s [1-7]. T h e results o f these s t u dies h a v e n o t a l w a y s b e e n in a g r e e m e n t however, a n d m o r e o v e r m o s t o f t h e w o r k on t h e r m a l a n d t h e r m a l - o x i d a t i v e d e g r a d a t i o n of p o l y d i m e t h y l s i l o x a n e has b e n e * Vysokomol. soyed. AI3: No. 8, 1727-1733, 1971.
1936
6. Z.A. KOCHNOVA and M. F. SOROK1N, Lakokras. mat. i ikh primenenie, No. 6, 78, 1966 7. lYI.F. SOROKIN, Z. A. KOCHNOVA and B. N. GRAFKIN, Lakrokras. mat. i ikh primenenie, No. 4, 1, 1967 8. V. A. KARGIN and G. L. SLONIMSKH, Kratkie ocherki po fiziko-khimii polimerev (Short Essays on the Physical Chemistry of Polymers). Izd. "Khimiya", 1967 9. V. A. KARGIN, Uspekhi khimii 35: 1006, 1966 10. V. Ye. BASIN, V. I. YELINEK, T. N. GANINA and L. M. KORSUNSKII, Programma VII konferentsii po elektronnoi mikroscopii (Programme of the Seventh Conference on Electron Microscopy). Kiev, 1969 11. K. KUTSUYA, J. Polymer Sci. B3: 403, 1965 12. B. J. SPIT, Polymer 4: 109, 1963 13. M. R. KISELEV, E. N. YEVKO and V. M. LUKYANOVICH, Zavod. lab. 32: 201, 1966
ELECTROPHYSICAL
PROPERTIES
OF SOME
AND
ULTRAVIOLET
SPECTRA
POLYAZOPOLYARENES*
V. G. KOSTROVSKII, YE. D. •ITMAN, A. I. SHPON'KO, V. G. ~L~ZUR, IV[. P. TERI~UGOVA a n d I. L. KOTLYAREVSKII
Institute of Chemical Kinetics aud Combustion, Siberian Branch of the U.S.S.R. Academy of Sciences
(Received 23 January 1970) THIS p a p e r presents m e a s u r e m e n t s of the ultraviolet spectra a n d o f the t e m p e r a t u r e d e p e n d e n c e o f the electrical c o n d u c t i v i t y o f p o l y a z o p o l y a r e n e s with alkoxy- or dialkyl(arylalkyl)amino.groups as s u b s t i t u e n t s in t h e repeating unit o f t h e p o l y m e r chain, a n d containing sulphur atoms, nitrogen atoms or aliphatic bridges between the benzene nuclei. T h e p r e p a r a t i o n and properties of the polymers are described in references [1] a n d [2]. T h e electrical conductivities were m e a s u r e d b y the m e t h o d of reference [3]. The results are p r e s e n t e d in Table 1 a n d Fig. 1. T h e t e m p e r a t u r e d e p e n d e n c e of the specific electrical c o n d u c t i v i t y o f these p o l y m e r s is expressed b y the e q u a t i o n log a--~log aoE/]cT. T h e relationship bet w e e n log a 0 a n d E is linear (compensation effect, Fig. 1). The slope of the line (A log ao/AE~ l/To) corresponds to the t e m p e r a t u r e 200 °, a t which t h e specific electrical conductivities o f all the polymers are closest to one another, lying within t h e limits of 3 × 10 -11-+1 ohm-1, cm-1. T h e c o n d u c t l• w•t y asp 2o is 10-~e± a o h m -1. cm -~. I t is shown in reference [4] t h a t the position of a point on the straight line representing t h e compensation effect is d e p e n d e n t on s t r u c t u r a l features o f the p o l y m e r t h a t d e t e r m i n e the packing density of the molecules. We were unable t o e x t e n d this relationship to the present series of polymers. * Vysokomol. soyed. A13: No. 8, 1721-1726, 1971.
Electrophysical properties of some polyazopolyarenes
1937
The ultraviolet spectra of some of the polymers were recorded, in order to establish the system of electronic states in polyazopolyarenes. The spectra were recorded in solution in diethyl ether, dioxan and dimethylformamide, in a Cary-15 spectrophotometer. The polymers are only partially soluble and obviously the
1 .Oo/
E,eV
o
~ 0 ~"
000 0
-o
o
0 0 O~
o
t
~
,
o
I
,
i
I
e
I
1
I
tOgao
FIo. 1. Relationship between the pre-exponential factor and the energy of activation for electrical conductivity of polyazopo]yarenes.
spectra can be attributed only to the low-molecular fractions.* The absorption spectra, and the energy level schemes and the transitions between them are presented in Fig. 2 and Table 2. In Table 2 ¢ and ~* are the ground state and excited energy levels of the ~electrons of the benzene nuclei respectively, r l , ~2 and ~ , ~e* the energy levels of the ~-eleetrons of the - - N ~ I q bond, and n= and n, the split levels of the unshared pairs of the nitrogen atoms. A similar assignment of bands is made in reference [5] for azobenzene. The spectra of polymers I, I I and X X I X are similar to the spectrum of azobenzene (Fig. 2a), b u t in addition to the bands noted in reference [5] there is a band at 200 m/l. The fact that this was not observed b y the authors of reference [5] is evidently explained b y the fact-that the wavelength range of their apparatus did not extend below 210 m/l. When the hydrogen atoms in the para-position of azobenzene are replaced b y carbon atoms in these polymers a small longwave shift of all the bands occurs. The band in the 440 m/l region corresponds to the n~,s->~* transition. The broadness of this band is explained b y splitting of the n levels. According to reference [5] the band at 340 m# corresponds to the ~1->~* (longwave e d g e ) a n d ~i->~* (shortwave edge) transitions. The ¢ 2 - ~ * and ~ - > ~ * The molecular weight of the soluble fractions of some of the polymers, determined by the inverse ebullioscopic method, corresponds to m =4-5 (Table 1).
V . G. KOSTROVSKII
1938
et aL
T A B L E 1. E L E C T R I C A L OONDUOTIVITIES OF P O L Y A Z O P O L Y A R E N E S
PolymerNo.
Chemical f o r m u l a
E, eV logao
I
1-39 I
+, •
II
CHs
--
4.6
a;:~ 3.5X I 0 - '
I
1"0 X 10 -la ~H a
H , _- ~ / _- - N _ _,%_// / = \ _ _ S ~ - ~ ' ~%_.//-- FI_Y-H2 -]~-
III
H,--(--N~\
IV
- t-
H
'%_//--
9"0 X 10 - i s
S0,--/=\--N--~--H,
"%_//
/ = N--/=~--N
=
4"0 X 10 -1~
-]~-
-/~\-N
= \ =
H 1'0 X 10 - l e
V H--/
N
/=\
N
z l= ~ J
VI
\
~,--// "%--//
\
c,/
H -/-
H
IX
-/--N--Y=\--/=\--\
% / - - // "%- - // \
• i H.C.0 H,- /
-|-t,
X
\-
% // ",~ //
--I-
- H,
--i-
4"1 X 10 - i s H,
6"2 X 10 -re
0-o-0,., /o /oc5, 1.6 X 10 - i s
5,=
H,=
=
5.oo~--~/
N--(~--N~
XII
o,
XIII
+ -- I,g ,
H2--
/~
,-N
~.
\//\0-n-C,H,
\
0:
XV XVI *
-\
--~ - / = \ - 7 = \ - ~ - \ -
o~5,
XlV
3.5 X 10 -17
0C.H. /m
5,co\ XI
H,
/m
"OCH.
'-I--
5"0 × 10 -~1 /m
-l-
%--(/ %--// / ",,
H,CO"
3"9 X 10 - i s
/m
-|
\c~
N--/=\--/=\--~-
'-I-"
VIII
I
n-CsH~,
'-/-
VII
/~\--N--\=H
~J
"
0 n 0,5.
H~
]2' 1.9 X 10 -~8
1.7 X 10 - ~
)?.
)?,
2'0 × 10 -15
1"0 X 10 -1~
1"1 X 10 -15
* The molecular weights of polymers XVI, XVII a n d X V I I I were determined b y analysis of their hydrochlorides [1].
1939
Eleetrophysical properties of some polyazopdlyarenes T~B~.E 1 (cont.) Polymer No.
Chemical f o r m u l a
"("
XVlI *
E , eV loga0
)2
~
0"83
1"0 × 10 -x4
0"60
7"0 X 10 -14
0"64
5"1 × 10 -la
XX
1.04
5"3 × 10 -x~
XXI
0"79
1"0 X 10 -x5
XXlI
0"87
1'6 × 10 -xs
0"87
2-0 X 10-1=
1"78
5"1 × 10 -I1
1"58
1"0 X 10 -21
0"66
2.5 × 10 -is
0"67
4"2 X 10 -16
0"57
1"0 X 10 -x4
1"17
5"7 × I0 -s2
0"65
5"3 × 10 -15
1"4
6"0 × 1 0 - "
0"74
4"8 X 10 -15
~,-/-~J=\
~
"~
XVlII * O-n-Ca]~ ?
19--21
)
H = /=~--/:\--N(CH
XlX
o.-.,. . .
II ~
I
XXIII
L
\//%
\
~\
"~--Z/m
~Hs~ /
H,- [-- N ~ \ - - ~ ' ~ - - - N - XXIV
- l-
\ H,C0
XXV
)--Y
"~--'~
-
0OH,
N- / = \ --/---~\--N --'~ -- H, ~ - - ~ "~--~ -)-
/m
/
?-Y
\ H,C0 XXVI
[
/--'-. /
\//\
/
0CHs HsC
H, -- ./ = ~ _ /..~_~/ = . x _~_~/ ~\_~
~sCO/
= ~ _ _~_-/ /=\_~
\OCH.
CHs
/m
-_ ,\ - _ )~
H,
XXVII
\ a.co XXVIII
'-I-
ooa, --~_Y
",~_//-- \0CH,
k HsC0
XXIX XXX
~ ~ / ~ a , ~T= /--\
,~ // ,, :/--~-~-H. --/~~.--.-(- ~-~,,=>,,--c~. ,--~=,-3
'-t-
--'~_// %,_//
-/~
~,
).
~ \ ~ = \ ~ - / / - - N--\--H ' ---/-~T /--~__~/ -/' XXXI XXXII
k
H*C /
\CH, /~
V. G. KOSTROVSEIIe~ al.
1940
transitions should lie in the region of 280 m/~, but are prohibited and therefore their intensity is low. The authors of reference [5] ambiguously assign the band a t 2 4 0 m/~, either to the ~ - ~ 5 " transition or to a possible ~5->u~ transition. Since in contrast to those authors we were able to record the strong band in t h e 200 nap region, which is assigned to ~ - ~ 5 . transitions in benzene, the only possible assignment of the band at 240 m/~ is to the ¢ ->u* transition. D
I-0
))
,.~
-
d
,Z,J
IV , ~
I:
-.~
LI ', ,,/I, 0"5
1"0 I
0"5
I
~,;
1"-'7
I
I I"~---r"
I
I
I
I
1"0
I
)
I
i
T'~-t--
f 2
0"5 /\
//~\
\. I
P
300
I
f
J
I "~'~
500
J
[
300
J
I
J
5gg
---
A, m~
Fie. 2. Ultraviolet spectra of polyazopolyarenes: a: 1 - - I , 2--11, 3 - - X X I X ; b: 1 - - X X X a , 2 - - X X X ; 3 - - X X X b ; c: 1 - - X X X I , 2 - - V I I ; d - - I I I ; e: 1 - - X X X I I , 2--V; f - - f r a c t i o n of polymer X X I soluble in ether (1), in dioxan (2) and in dimetbylformamide (3).
No band shifts occur in the spectra of 4,4'-diaminoazodiphenyl (the product of oxidative dimerization of benzidine) (XXX), of polymer XXXa, obtained by oxidative polycondensation of dimer X X X , or of polymer XXXb, obtained from benzidine (Fig. 2b). This indicates that interactions of electrons in these conjugated systems die out almost completely at a distance of two monomer units. The only noteworthy change in the spectra of X X X , X X X a and X X X b is broadening of the bands on passing from the dimer to the polymers. Qualitatively there is no difference between the energy-level schemes for azobenzene and polymer XXXb. In the latter, because of the effect of the additional benzene nucleus oh the azo-group, the energy levels of its n-electrons are closer together than in
Eleetrophysical properties of some polyazopolyarenes
1941
TABLE 2. FREQUElqCIES OF THE TRANSITIONSIN THE ULTR/kVIOLETSPECTR~- OF POLYAZOPOLYARENES
I II XXIX XXX a,b XXXI VII III J-transition XXXII V
195 195 195 205 211 218 205 Strong 195 195
240 235 237 263 264 268 255 Strong ~255" ~0255"
335 338 340 410 420 425 385 Strong 440 450
340 343 344 415 425 435 395 Strong 450 500
~ 280 280 280 300 ~ 300 ~ 300 ~ 300 Weak N315
J-transition
Strong
Weak
Strong
Strong
Weak
* For polymersXXXII
and V- •
~315
440 440 ~ 440 ~ 500 ~ 500 ~ 530 ~480 Weak ~ 530 525 Strong Weak
-->~a.
p o l y m e r s I a n d II. On t h e basis o f the conclusions o f reference [5] it m a y be concluded t h a t t h e ~ level does n o t undergo a large shift. T h e n t h e b a n d a t 417 m/~ will obviously correspond to t h e ~1->~* (longwave edge) a n d 4 - > ~ (shortwave edge) transitions, a n d t h e b a n d at 263 m/~ t o t h e 4 - > ~ transition. I n t r o d u c t i o n of - - C H 3 a n d --C1 as s u b s t i t u e n t s in t h e ortho-position to t h e azo-group (polymers V I I a n d X X X I ) causes a longwave shift o f the b a n d in t h e 200 m~ region (Fig. 2c). This is explained b y t h e resonance effect of t h e substit u e n t on t h e benzene nucleus [6]. This shift is one of the a r g u m e n t s in f a v o u r of assignment of t h e 200 m/~ b a n d to t h e 4 ->4* transition. S u b s t i t u t i o n o f sulphur as a bridging a t o m (polymer I I I ) in place of an alip h a t i c group, has little effect on t h e levels of either the benzene nuclei or the azo-groups (Fig. 2d). T h e s p e c t r u m of p o l y m e r X X X I I indicates t h e presence o f conjugation (Fig. 2e). H e r e t h e r e is no shift in t h e ~5 and 4 " levels of the benzene nuclei in comparison w i t h those levels in p o l y m e r s I a n d II. T h e strong b a n d a t 450 m/~ corresponds to transitions of the s y s t e m of levels ~ - ~ and 4 - > ~ , shifted to the longwave region as a result of conjugation. T h e b a n d corresponding to t h e n~,s --->~ t r a n s i t i o n should a p p e a r in the same region (530 m~). I n fact in the s p e c t r u m of p o l y m e r V the levels of t h e u n s h a r e d electron pairs o f t h e nitrogen in the y - - N = N - - a n d N H bonds are s o m e w h a t different as a result of increased p r o b a b i l i t y of the n~,s ->~* transition, a n d t h e r e is a strong d o u b l e t a t 500-525 m/l. I n o t h e r respects t h e spectra of polymers X X X I I a n d V are t h e same. F r o m t h e spectra of t h e various fractions of p o l y m e r X X I (Fig. 2f, fraction 1, which is soluble in ether, consists m a i n l y o f the dimer, fraction 2, soluble in dio x a n and fraction 3, soluble in d i m e t h y l f o r m a m i d e ) r e c o r d e d in d i m e t h y l f o r m a mide, it is seen t h a t as the chain length increases all t h e bands b e c o m e broader,
1942
K . A . A~DRIA_N'OVeta[.
as in the case of lJolymer XXXb, and the spectrum loses its structure. This broadening of the bands can be explained by scattering of the light on the long polymer molecules. CONCLUSIONS
(1) The electrical conductivity of twenty eight polyazopolyarenes has been measured. (2) The electronic transitions in some of the polyazopolyarenes have been established. Translated by E. O. PK~y~PS REFERENCES 1. M. P. TERPUGOVA, V. G. MAZUR, I. L. KOTLYAREVSKH~ N. A. LAPSHINSKAYA
and Z. P. TROTSENKO, Izv. Akad. Nauk SSSR, ser. khim., 2351, 1970 2. M. P. TERPUGOVA, I. L. KOTLYAREVSKH and E. K. ANDRIEVSKAYA, Izv. Akad. Nauk SSSR, set. khim., 1854, 1964 3. V. G. KOSTROVSKII, I. L. KOTLYAREVSKII, A. S. ZANINA and S. I. SHERGINA, Vysokomol. soyed. Bl1: 334, 1969 (Not translated in Polymer Sei. U.S.S.R.) 4. I. L. KOTLYAREVSKII, M. P. TERPUGOVA, N. M. BAZHIN and M. F. BASHKIROV, Izv. Akad. Nauk SSSR, set. khim., 1620, 1966 5. H. H. JAFFE, S. I. YEH and R. W. GARDNER, J. Mol. Spectroscopy 2: 120, 1958; H. H. JAFFE and M. ORCHIN, Theory and Application of Ultraviolet Spectroscopy, pp. 278, 280, New York-London, 1962 6. W. WEST (Ed.), Primenenie spektroskopii v khimii (Application of Spectroscopy in Chemistry). Foreign Literature Publishing House, 1959 (Russian translation)
THE VARIATION IN THE VISCOSITY AND MOLECULAR-WEIGHT PARAMETERS IN LOW-TEMPERATURE DEGRADATION OF POLYDIMETHYLSILOXANE P R E P A R E D WITH INITIATORS OF DIFFERENT STRUCTURE* K . A. ANDRIANOV, S. A. PAVLOVA, I. I. TVERDOKHLEBOVA, N. V. PERTSOVA a n d I. V. ZHURAVLEVA Institute of Hetero-organic Compounds, U.S.S.R. Academy of Sciences
(Received 27 January 1970) POLYDIMETHYLSILOXANE o b t a i n e d b y p o l y m e r i z a t i o n w i t h alkaline i n i t i a t o r s h a s b e e n t h e s u b j e c t of s t u d y of a n u m b e r of a u t h o r s [1-7]. T h e results o f these s t u dies h a v e n o t a l w a y s b e e n in a g r e e m e n t however, a n d m o r e o v e r m o s t o f t h e w o r k on t h e r m a l a n d t h e r m a l - o x i d a t i v e d e g r a d a t i o n of p o l y d i m e t h y l s i l o x a n e has b e n e * Vysokomol. soyed. AI3: No. 8, 1727-1733, 1971.