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The beginnings of physical organic chemistry can be traced back to the early 19th Century in the work of Michael Faraday, and this area of study gained great prominence with the discovery by Moses Gomberg of the triphenylmethyl radical in 1900. From that time, the field has continually grown in its capabilities and now is widely used for the understanding of organic and bioorganic chemistry, using both experimental and theoretical approaches. Some of the history of this development is described. 相似文献
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Paul W. Tidwell George A. Mortimer 《Journal of polymer science. Part A, Polymer chemistry》1970,8(6):1549-1556
The method of determining chain-transfer constants in polymer systems, originally developed by Mayo, has been extended to the simultaneous determination of constants for several transfer agents. The validity of various calculation methods was examined. Particular attention was devoted to the question of how precisely chain-transfer constants are known. This extended method was applied to the determination of chain-transfer constants in ethylene polymerization under conditions where the limiting molecular weight in the absence of transfer agents cannot be directly measured, and it was shown that precision is improved (uncertanty reduced) by simultaneously determining more than one transfer constant. 相似文献
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Allen AD Cheng B Fenwick MH Givehchi B Henry-Riyad H Nikolaev VA Shikhova EA Tahmassebi D Tidwell TT Wang S 《The Journal of organic chemistry》2001,66(8):2611-2617
Tetramethylpiperidinyloxy (TEMPO, TO*) reacts with ketenes RR(1)C=C=O generated by either Wolff rearrangement or by dehydrochlorination of acyl chlorides to give products resulting from addition of one TEMPO radical to the carbonyl carbon and a second to the resulting radical. Reactions of phenylvinylketenes 4b and 4f, phenylalkynylketene 4c, and the dienylketene AcOCMe=CHCH=CHCMe=C=O (11) occur with allylic or propargylic rearrangement. Even quite reactive ketenes were generated as rather long-lived species by photochemical Wolff rearrangement in isooctane solution, characterized by IR and UV, and used for kinetic studies. The rate constants of TEMPO addition to eight different ketenes have been measured and give a qualitative correlation of log k(2)(TEMPO) = 1.10 log k(H(2)O) -3.79 with the rate constants for hydration of the same ketenes. Calculations at the B3LYP/6-311G//B3LYP/6-311G level are used to elucidate the ring opening of substituted cyclobutenones leading to vinylketenes and of 2,4-cyclohexadienone (17) forming 1,3,5-hexatrien-1-one (18). 相似文献
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Aguilar-Aguilar A Allen AD Cabrera EP Fedorov A Fu N Henry-Riyad H Leuninger J Schmid U Tidwell TT Verma R 《The Journal of organic chemistry》2005,70(23):9556-9561
[Structure: see text]. Ferrocenylketene (1) is calculated to be destabilized by 1.6 kcal/mol relative to phenylketene (10) by B3LYP isodesmic comparison to the corresponding alkenes. Ketene 1 generated by Wolff rearrangement in CH3CN is identified by the IR band at 2119 cm(-1) and has a rate constant for reaction with n-BuNH2 less than that for 10 by a factor of 5. 1,2-Bisferrocenyl-1,2-bisketene 18 and 1-ferrocenyl-2-trimethylsilyl-1,2-bisketene 21 were prepared by photochemical ring opening of the corresponding cyclobutenediones, and 18 undergoes rapid ring closure 67 times faster than the corresponding 1,2-diphenyl-1,2-bisketene, while bisketene 21 is longer lived than 18 by a factor of 3.2 x 10(4). 相似文献
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Nakamura Y Inamura K Oomuro R Laurenco R Tidwell TT Nishimura J 《Organic & biomolecular chemistry》2005,3(16):3032-3038
The reactions of various aromatic diazoketones with [60]fullerene were investigated in solution (o-dichlorobenzene) or in the solid-state. Under all the conditions examined, the fulleroid with the methine proton located over a six-membered ring was obtained as a major product along with a slight amount of the other fulleroid diastereoisomer and methanofullerene. Solid-state reactions considerably enhanced the reaction efficiency with minor effects on the selectivity. The thermal isomerization and photoisomerization from fulleroids into methanofullerene were relatively slow, almost independent of substituents under the conditions examined. 相似文献