Aluminum and Gallium Hydrazides

Abstract

Aluminum and gallium hydrazides have found considerable interest in current research because they are potentially useful as single source precursors for the epitaxial growth of semi-conducting AlN or GaN films. Furthermore, they may exhibit singular structural properties owing to the capability of the hydrazido group to act as a bidentate ligand. The synthesis of those hydrazides succeeds by several methods, such as the alkane and hydrogen elimination, which requires the treatment of alanes or gallanes with hydrazine derivatives containing at least one N-H function. Furthermore, the formation of salts by the employment of lithium hydrazides and chloroaluminum orgallium compounds or the hydroalumination of 2,3-diazabutadiene derivatives are facile synthetic methods. These hydrazides adopt a great variety of structures with four-, five-, and six-membered heterocycles or with polycyclic frameworks and cages. With the exception of sterically insufficiently shielded derivatives of unsubstituted hydrazine N2H4, their thermal stability is high enough to allow a secure handling. Only at elevated temperature does thermolysis occur, which in some cases yielded the nitrides AlN and GaN.