Two monomeric gallium-nitrogen compounds Et2GaNH [C6H2 (2, 4, 6-t-Bu) 3] and EtGa {NH [C6H2 (2, 4, 6-t-Bu) 3]} 2 have been prepared and characterized. The compound Et2GaNH [C6H2 (2, 4, 6-t-Bu) 3], but not EtGa {NH [C6H2 (2, 4, 6-t-Bu) 3]} 2, decomposes at room temperature to form a new metallacyclic derivative {EtGaNH [C6H2 (4, 6-t-Bu) 2 (CMe2CH2-2)]} 2, GaEt3, and H2N [C6H2 (2, 4, 6-t-Bu) 3].