Abstract: | Preparation and Crystal Structure of Ethylenediammonium Selenostannates(IV) and 2 SnSe2 · en]∞ The selenostannates(IV) enH2]2Sn2Se6] · en 1 and enH2]Sn3Se7] · 1/2en 2 have been prepared by the methanolothermal reaction of SnSe2 with ethylenediamine (en) (160°C, 13 bar) in the presence of respectively Se or BaSe. The Sn2Se6]4? anion in 1 consists of two edgebridged SnSe4 tetrahedra and displays crystallographic Ci symmetry. The crystal structure of 2 contains polyselenostannate(IV) sheet anions Sn2Se72], for which the basic elements are trigonal SnSe5 bipyramids. Each of the three symmetry independent Sn atoms is linked to the other Sn atoms via Sn? Se? Sn bridges leading to the formation of Sn3Se10 units. Methanolothermal reaction of SnSe2 with en alone yields the edge-bridged chain structure 2 SnSe2 en]∞ 3 , in which each of the Sn atoms is bonded to four Se atoms. Every second Sn atom is also coordinated by an en molecule and displays, therefore, an octahedral geometry. The remaining Sn atoms are coordinated tetrahedrally by Se atoms. |