Crystal structure and properties of indium telluride [Ga(en)(3)]In3Te7

[Ga(en)(3)]In3Te7 (I) has been synthesized by solvothermal technique using Rb2Te, GaC3, InCl3 and Te as starting materials and ethylenediamine as solvent at 180 degrees C for 7 days. The structure consists of a Zintl anion, (2)(infinity) [In3Te7](3-) and a complex cation, [Ga(en)(3)](3+). I belongs to the monoclinic, space group P2(1)/c, (no. 14), with unit cell dimensions: a = 1.0460(2) nm, b = 1.6981 (3) nm, c = 1.4994(6) nm, beta = 95.46(2)degrees, V = 2. 651 (1) nm(3), Z = 4. Optical studies were performed on the powder samples, which suggested that I is a semiconductor with a band gap of 1.65eV. The result of TGA thermal analysis on I indicated that the weight loss of enthylendiamine proceeded in three steps. The decomposition of I produced Ga2Te3, In2Te3, Te and ethylenediamine as the final residues.