Nucleophilic Triphenylgermanides of Magnesium and Calcium

Abstract

The dimeric calcium and magnesium hydrides, [(BDI)AeH]2 [BDI = HC{(Me)CNDipp}2, Dipp = 2,6‐i‐Pr­2C6H3;­ Ae = Mg or Ca] do not react with Ph3GeH in non‐coordinating solvent. Addition of THF, however, induces deprotonation and access to monomeric Ae‐germanide complexes, [(BDI)Ae{GePh3}(THF)], both of which have been structurally characterized. Although this process is facile when Ae = Ca, the analogous magnesium‐based reaction requires heating to temperatures >100 °C, under which conditions germanide formation is complicated by THF ring opening and the generation of an alkaline earth germyl‐C‐terminated n‐butoxide, [(BDI)|Mg{μ2‐O(CH2)4GePh3}]. Reactions of [(BDI)Ca{GePh3}(THF)] with N,N'‐di‐isopropylcarbodiimide and benzophenone provide the respective germylamidinate and germylalkoxide derivatives, [(BDI)Ca{(i‐PrN)2CGePh3}(THF)] and [(BDI)Ca{OC(GePh3)Ph2}(THF)], demonstrating its potential as a well‐defined and soluble source of the [Ph3Ge]− anion in nucleophilic addition reactions.