Structural diversity in a homologous series of donor free alkali metal complexes bearing a sterically demanding triazenide

Abstract

The reactivity of the sterically demanding triazene Dmp–NN–N(H)–Dmp (Dmp₂N₃H, Dmp = 2,6-bis(2,4,6-trimethylphenyl)phenyl) with alkali metal bases and elemental heavy alkali metals has been examined. All reactions afforded the respective alkali metal triazenide complex. The solid-state molecular structures of these complexes display κ²-N,N′-chelation of the triazenide by the metal. The coordination sphere of each metal center is further furnished by M⋯π-arene interactions to the pendant mesityl groups of the triazenide, which enables each complex to exist as a mononuclear species with complexes of the heavier alkali metals display weak aggregation in solid-state. A heteroleptic dilithium complex, featuring μ–κ¹-N,N′-bridging of the triazenide by the two lithium centers, was also characterized.