MECHANISM OF THE ZIEGLER DILITHIOMETHANE SYNTHESIS - AN ABINITIO STUDY OF METHYLLITHIUM PYROLYSIS
van Eikema Hommes N, Schleyer P, Wu YD (1992)
Publication Status: Published
Publication Type: Journal article
Publication year: 1992
Journal
Publisher: American Chemical Society
Book Volume: 114
Pages Range: 1146-1151
Journal Issue: 4
Abstract
Ziegler's disproportionation reaction of methyllithium to give dilithiomethane and methane upon heating to 225-degrees-C is predicted by ab initio theory (MP2/6-31 + G*//6-31G*) to proceed endothermically through a polar hydrogen-transfer mechanism within a tetrameric methyllithium aggregate, (CH3Li)4 --> CH2Li2.(Li/CH3)2 + CH4. A free energy of reaction of +19.6 kcal/mol and an activation barrier (DELTA-G double dagger) of 53.8 kcal/mol at 500 K are computed. The alternative reactions within dimeric and trimeric aggregates are endothermic by 31.1 and 21.4 kcal/mol at MP4SDTQ/6-31 + G*//6-31G* with activation barriers of 64.3 and 58.2 kcal/mol, respectively. Under the reaction conditions, methyllithium trimers should be in equilibrium with tetramers, but tetramers are still expected to be the predominant species.
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APA:
van Eikema Hommes, N., Schleyer, P., & Wu, Y.-D. (1992). MECHANISM OF THE ZIEGLER DILITHIOMETHANE SYNTHESIS - AN ABINITIO STUDY OF METHYLLITHIUM PYROLYSIS. Journal of the American Chemical Society, 114(4), 1146-1151.
MLA:
van Eikema Hommes, Nico, Paul Schleyer, and Yun-Dong Wu. "MECHANISM OF THE ZIEGLER DILITHIOMETHANE SYNTHESIS - AN ABINITIO STUDY OF METHYLLITHIUM PYROLYSIS." Journal of the American Chemical Society 114.4 (1992): 1146-1151.
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