Reversible dimerization of 9-cyano-10-methylacridinyl radical

The electrochemical reduction of the 9-cyano-10-methylacridinium cation in acetonitrile yielded the corresponding radical, which was rather stable at 20 °C and gave a resolved ESR spectrum. This radical reversibly dimerized in the temperature range from 20 to −30 °C. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1444–1445, August, 2006.     

Cobalt-catalyzed dimerization of alkenes

In the presence of CoX₂(PPh₃)₂/3 PPh₃ and zinc metal conjugated alkenes (CH₂CHCOOR, CH₂CHCN, CH₂CHSO₂Ph and CH₂CHCONEt₂) undergo reductive tail-to-tail dimerization to yield the corresponding saturated linear products. Under similar reaction conditions, vinylarenes (ArCHCH₂) give stereoselective head-to-tail dimerization products, trans-1,3-diarylbut-1-ene, in good to excellent yields.     

Triple Click Reaction Strategy for Macromolecular Diversity

This Feature Article focuses on the rapidly emerging concept of the “triple click reactions” towards the design and synthesis of macromolecules with well‐defined topology and chemical composition, and also precise molecular weight and narrow molecular weight distribution. The term “triple click reaction” used in this feature article is based on the utilization of three chemically and mechanistically different click reactions for polymer–polymer conjugation and post‐modification of the polymers. Three sequential click reactions of which two are identical should not be considered to be triple click reactions. The triple click reaction strategy for polymer conjugation and post‐modification of polymers is classified in this article based on the resultant architectures: linear and non‐linear structures.     

Numerical Studies of Ground State Phase Diagrams for the MMX Chains

Abstract

We study ground state phase diagrams for the MMX chains, using a one-dimensional dimerized 3/4-filled extended Hubbard-Peierls model with site diagonal and off-diagonal electron-lattice interactions. The ground states are obtained mainly in the Hartree-Fock approximation, and their accuracy is checked by the exact diagonalization of small clusters. We find a new phase in addition to frequently considered phases and compare our results with experimental results.