chemical physics of discharges - Argonne National Laboratory
chemical physics of discharges - Argonne National Laboratory chemical physics of discharges - Argonne National Laboratory
LUd The actual structural definition must await isolation of sufficient quantities of the com- ponents for NMR studies under various conditions. The possibility of a hydrogenated p-terphenyl was carefully considered, but the only structure even remotely consistent with the infrared and NMR data would require that the center ring of p-terphenyl be non-aromatic with m'ono-substituted phenyl groups attached. Such a material could be formed by preferential hydrogenation of the center ring of p-terphenyl (statistically unlikely ) or by the reaction of phenyl radicals and 1,3 -cyclohexadiene as follows: This mechanism requires the formation of hydrogenated ortho terphenyl derivatives such as VIII, which were not noted by gas-liquid chromatography or infrared. TABLE 3 Biphenyl Fraction (a) X Yield % Exposed Benzene Biphenyl 0.30 o - Terphenyl 0.05 m - Terphenyl 0.02 p-Terphenyl Benzyl and phenyl cyclopentenes (C12 1 0.05 0.05 Phenylbenzylcyclopentenes ( Cle) 0.25 TOTAL 0.72 VI1 (3) Yield % Reaction Products 3.5 0.6 0.2 0.6 0.6 -% (a) Quantitative data were obtained by GLC, using a silicone gum rubber column with appropriate standard calibration curves based on peak height.
Polymeric Products The material which adheres to the glass dielectric surface in the reactor is a high melting solid ( 3 320°), insoluble in benzene and all common solvents. The infrared spectrum and the carbon-hydrogen ratio are essentially the same as noted for the benzene soluble material. The benzene soluble polymer was fractionated into three molecular weight ranges based on solubility in isooctane. The polymers are all yellow with the in- tensity increasing as the molecular weight decreases. The ultraviolet spectrum for the low molecular weight polymer shows a gradual tailing into the visible region. The physical property data for the polymeric fractions are summarized in Table 4. Infrared data indicate that the polymeric fractions are structurally similar to the low molecular weight products identified as benzyl and phenyl substituted cyclopentenes. The infrared evidence already presented for the low molecular weight products is applicable to the polymeric products and need not be repeated. The data are consistent with an average repeating unit containing the cyclopentene ring structure substituted with phenyl or benzyl groups. NMR data for the polymers were obtained in carbon tetrachloride at the cell holder temperature (40"). The spectrum obtained for the 300 molecular weight polymer fraction is presented in Figure 5. The extreme broadening of the proton resonances is associated with the complex, long range roton coupling in a risd system and the motional averaging commonly noted in polymers .'2 Scanning the same sample at 90°-in tetrachloroethylene did not significantly improve the resolution. The NMR spectrum of the- polymer in .pyridine (Figure 5 ) gives some improvement in the high field proton resolution, indicating a doublet at 2.6 ppm (benzylic protons ) and a complex methyl "proton resonance. The spectra are similar to those obtained for the low molecular weight precursors containing unresolved , ring protons. The NMR spectra generally eliminate polymer formation by:way of phenyl and hexatrienyl radicals as suggested for the radiolysis of benzene.23 The aliphatic proton portion of the spectrum is very similar -to that reported for cyclopentadiene polymers by Davies and Was~ermann.~~ The cyclopentadiene polymers had a molecular weight range of 1200-2300, ah'max.at 320-360 mp and non-olefinic proton to olefinic proton ratio of approximately 3/1. The data are consistent with polymer formanon by way of phenyl radical (or excited benzene) reaction with the fulvene produced to give phenyl or benzyl substituted cyclopentadienes which then polymerize to gve a polycyclopentene chain with pendant phenyl and/or benzyl groups. The average non-olefinic to olefinic proton ratio of 2.9 indicates that the many possible structures similar to XI (5/2) predominate over the alternate type structures, XI1 (7/0), 24 assuming our analogy to cyclopentadiene type polymers is valid. Q &, XI Many similar structures must be considered, including those derived from phenyl attack on the ring with polymerization through the exocyclic vinyl group of fulvene. (4)
- Page 404 and 405: 0 IS 0 14 LL 9 013 e \ 3 b- m *- 01
- Page 406 and 407: 402 HYDROGEN CYANIDE PRODUCED FROM
- Page 408 and 409: 404 Before startup, the system is p
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- Page 412 and 413: Table 3.- Product Gas Analyses and
- Page 414 and 415: 410 BIBLIOGRAPHY 1. American Public
- Page 416 and 417: Figure 2. Enclosure surrounding hyd
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- Page 420 and 421: 0. E c .4 7 .. .c . I ( - Low tempe
- Page 422 and 423: 418 cual. A mjor aa\;antage or' the
- Page 424 and 425: 420 Ir ?Y ? ? 9 9 9 pc rod n o c o
- Page 426 and 427: 422 Table 3. Room-texperature M'dss
- Page 428 and 429: 424 state, depending on the strengt
- Page 430 and 431: Table 4. Room-?;ergerature isomer s
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- Page 434 and 435: Brooks J.D. and Sternhell S. (1957)
- Page 436 and 437: (52) Gib3 T.C. and Greenwood N.N. (
- Page 438 and 439: 434 transducer vas then introduced
- Page 440 and 441: 436 yield is quite similar. The con
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- Page 444 and 445: 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 4
- Page 446 and 447: 442 CHEMICAL REACTIONS IN A CORONA
- Page 448 and 449: helium 444 CORONA REACTOR SYSTEM Fi
- Page 450 and 451: 446 The ultraviolet spectrum. for t
- Page 452 and 453: Biphenyl Fraction 448 The low molec
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- Page 458 and 459: ’. 454 Mechanism I The available
- Page 460 and 461: 456 , , . The relatively low yield
- Page 462 and 463: 458 h/lethylacetylene, allene and b
- Page 464 and 465: Introduction VAPOR PHASE DECOMPOSIT
- Page 466 and 467: 462 more efficient hydrogenation. T
- Page 468 and 469: 464 place in parallel with fragment
- Page 470 and 471: 466 P rl 0, k 7 rnI rn al k a I hl
- Page 472 and 473: 458 TABLE I. COMPOSI'IION OF GASEOU
- Page 474 and 475: REFERENCES 1. C. Hirayama and D. A.
- Page 476 and 477: i 472 Reciprocal Arc Enthalpy ,-> F
- Page 478 and 479: 474 be pumped down without altering
- Page 480 and 481: 476 Instead a hydrogen deficient fi
- Page 482 and 483: i 478
- Page 484 and 485: 480 FATTY ACIDS AND n-ALKANES IN GR
- Page 486 and 487: 482 TA5L,E 2. - Carbon number distr
- Page 488 and 489: 6. 7. a. 9. 484 Lawlor, D. L., and
- Page 490 and 491: ' I ' Sample No. 6 ' 12 IO 8 6 z 4
- Page 492 and 493: . 488 uiolecular weight of which ca
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LUd<br />
The actual structural definition must await isolation <strong>of</strong> sufficient quantities <strong>of</strong> the com-<br />
ponents for NMR studies under various conditions. The possibility <strong>of</strong> a hydrogenated<br />
p-terphenyl was carefully considered, but the only structure even remotely consistent<br />
with the infrared and NMR data would require that the center ring <strong>of</strong> p-terphenyl be<br />
non-aromatic with m'ono-substituted phenyl groups attached. Such a material could be<br />
formed by preferential hydrogenation <strong>of</strong> the center ring <strong>of</strong> p-terphenyl (statistically<br />
unlikely ) or by the reaction <strong>of</strong> phenyl radicals and 1,3 -cyclohexadiene as follows:<br />
This mechanism requires the formation <strong>of</strong> hydrogenated ortho terphenyl derivatives such<br />
as VIII, which were not noted by gas-liquid chromatography or infrared.<br />
TABLE 3<br />
Biphenyl Fraction (a)<br />
X<br />
Yield %<br />
Exposed Benzene<br />
Biphenyl 0.30<br />
o - Terphenyl 0.05<br />
m - Terphenyl 0.02<br />
p-Terphenyl<br />
Benzyl and phenyl cyclopentenes (C12 1<br />
0.05<br />
0.05<br />
Phenylbenzylcyclopentenes ( Cle) 0.25<br />
TOTAL 0.72<br />
VI1<br />
(3)<br />
Yield<br />
% Reaction Products<br />
3.5<br />
0.6<br />
0.2<br />
0.6<br />
0.6<br />
-%<br />
(a) Quantitative data were obtained by GLC, using a silicone gum rubber column with<br />
appropriate standard calibration curves based on peak height.
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