The solvothermal technique was used for the synthesis of [(enH)2 (enH2)Sn2Se6] (en= ethylenediamine) which contains a [Sn2Se6]4- Zintl anion, two [enH] + and one [enH2]2+ cations. The reactants with a molar ratio of K2Se:SnCl2·2H20:Se:en= 1:1:4=48 were reacted at 150 ° C for 7 d. The crystal structure of [(enH)2(enH2)-Sn2Se6] was determined by X-ray crystal structure analysis to belong to triclinic space group P 1 with the unit cell parameters, a =0.86599(2) nm, 6 = 1. 1055(2) nm, c =0.66360(10) nm, α= 104.44(3)°, β= 110.93(3)°, γ= 79. 74(3)°, V-0.57178(19) nm"3, Z = 1. Studies on optical properties for the powder sample suggest that this compound is a semiconductor with a band gap of 1.76 eV and an absorption coefficient of 0.0105 μm-1 to solar radiation. The result of thermogravimetric (TG) analysis indicates that [(enH)2(enH2)Sn2Se6] is stable up to 180 °C .

Key words: SELENIUM COMPOUNDS, ORGANO TIN COMPOUND, OPTICAL PROPERTIES, SEMICONDUCTOR, CRYSTAL STRUCTURE, STABILITY