Darstellung, Struktur und einige Reaktionen von Tris(dimethylamino)gallan / Preparation, Structure and Some Reactions of Trisdimethylaminogallane

Abstract

The aminogallanes Ga[N(CH 3 ) 2 ]3 (1), ClGa[N(CH 3 ) 2 ] 2 (2) and Ga[N(Si(CH 3 ) 3 ) 2 ] 3 (3) are prepared by reacting GaCl 3 with LiN(CH 3 ) 2 and NaN[Si(CH 3 ) 3 ] 2 , respectively. Excess LiN(CH 3 ) 2 leads to LiGa[N(CH 3 ) 4 ] which reacts with GaCl 3 to yield 1. CS 2 inserts into all Ga—N bonds of 1 yielding monomeric Ga[S 2 CN(CH 3 ) 3 ) 2 ] 3 (4). 1 dimerizes via dimethylamino bridges. In contrast, 1 H. NMR spectra indicate group exchange for dimeric 2. Assoziation of 3 is prevented due to steric hindrance. The gallium atom in 4 exhibits hexacoordination, and there is evidence for the binding of the (CH 3 ) 2 NCS 2 groups through S atoms only.