The organogallium azides
(N3)2
-
a
(R)
a
Ga[(CH2)3NMe2]1
-
a
(1a-c: R = CH3, tBu;
a = 0, 1),
(Et)(N3)2Ga (2a), and
(Et)(N3)2Ga·L
(2b
−
d: L = thf,
H2NtBu, py,
NC7H13) are quantitatively
synthesized by salt metathesis from the chloro species
(Cl)2
-
a
(R)
a
Ga[(CH2)3NMe2]1
-
a
(a = 0,
1) or EtGaCl2 and sodium azide. The preferential
ammonolysis of Ga−N3 bonds for
[Et2Ga(N3)]3 (4) and
1 and 2 is demonstrated; e.g. the dimer
Et2Ga(μ-NH2)(μ-N3)GaEt2
(3)
was obtained. The characterization of these compounds by means of
elemental analysis,
1H-, 13C-, 14N-, and
15N-NMR, MS, and infrared ν(N3) data is
reported. The dynamics of the
intramolecular Ga−N donor−acceptor bonded heterocycle and the azide
group is discussed
on the basis of variable-temperature NMR data. The barrier of
activation of the bimolecular
azide exchange process for
(N3)2Ga[(CH2)3NMe2]
(1c) amounts about 50
kJ·mol-1. The role
of ammonia as reactive carrier gas for low-pressure metal organic
chemical vapor deposition
(MOCVD) of GaN with 1c as precursor is discussed.