Synthesis of pyridine functionalised, sterically hindered lithium and copper (I) alkyls; crystal structures of [{2-(Me3Si)2C(M)C5H4N}2](M = Li or Cu), dimeric compounds free of multicentre bonding

Abstract

Reactions of 2-bis (trimethylsilyl) methylpyridine, (1), with LiBuⁿ in hexane–diethyl ether, and LiBuⁿ in tetrahydrofuran followed by CuCl, yields thermally robust binuclear complexes [{2-(Me₃Si)C₂(M)C₅H₄N}₂] for M = Li and M = Cu respectively in which the metal is not involved in electron deficient bonding, being bound by C_α of one ligand and the nitrogen of a centrosymmetrically related ligand and has a close metal contact [M ⋯ M 2.560(9)(Li) and 2.412(1)Å(Cu)].