Molecular Structure of Carbanions and the Kinetics of Their Exchange Processes in Solution. The Kinetics of Inversion of 2-Methylbutylmagnesium Bromide and Related Compounds

摘要

Analysis of the results of changes among n.m.r. spectra of 2-methylbutylmagnesium bromide and bis-(2-methylbutyl)-magnesium as a function of temperature in several ethers reveals that the changes are due to different rates of inversion at the CH2Mg carbon atom. In diethyl ether the kinetic order of the inversion process is 2.5 in contained Grignard reagent, and enthalpy and entropy are 12 + or - kcal and -11 + or - 2 e. u., respectively; for the organomagnesium compound, the order is 2.0, and enthalpy and entropy are 18 + or - 5 kcal and 5 + 2 e. u. Investigation is underway on the kinetics of the carbanion inversion in organo-lithium, -beryllium, and-aluminum compounds. Reaction between metals and hexamethyl phosphoramide indicate that the amide is reduced to tris-dimethyl-amino phosphine. Organometallic compounds are being synthesized from certain azo compounds, including RC(=O)N=NR' and RNHNH2.