Crystal Structure of [(α‐Cyanoisopropyl‐sodium · Tetramethylenediamine)4]: How Coordination Expansion from Li to Na Centers can Increase the Aggregation State of an α‐Nitrile “Carbanion”

Abstract

A tetrameric contact ion pair structure with a distorted cubane (NNa)4 core is revealed for the title complex 1. The structures of such α-nitrile “carbanions”–important intermediates in organic chemistry–are dependent on the identity of the metal employed, as a comparison with the related complex 2 with an (NLi)2 ring shows.