SOLVENTOTHERMAL SYNTHESIS OF THE LAMELLAR SELENIDOSTANNATES(IV) A(2)SN(4)SE(9)CENTER-DOT-H2O (A = RB, CS) AND CS2SN2SE6

Reaction of A(2)CO(3) with Sn and Se in an H2O/CH3OH mixture at 115-13 0 degrees C affords the isotypic lamellar selenidostannates A(2)Sn(4)S e(9) . H2O 1 (A = Rb) and 2 (A = Cs). The polyanions (2)(infinity)[Sn4 Se92-] exhibit Sn4Se5 molecular building units, in which two adjacent Sn(TV) atoms of an Sn4Se4 8-membered ring are bridged by an additional Se atom. These units connect through (SnSe)(2) 4-membered rings to af ford a 4(4) anionic net with 16-membered cavities. Cs2Sn2Se6 (3) may b e prepared by methanolothermal reaction of Cs2CO3 with SnSe and Se at 130 degrees C and contains porous (2)(infinity)[Sn2Se62-] sheets in wh ich (1)(infinity)[SnSe32-] ribbons are linked through Se-Se bonds. The resulting 4(4) net displays 14-membered pores in which the Cs cations reside.