Addition of triethylenetetramine (TETN) and tetramethylammonium (TMA+) to (\mathrm{SnS}{2}) and (\mathrm{SnSe}{2}) slurries followed by heating at (150^{\circ} \mathrm{C}) under autogenous hydrothermal conditions results in novel thio and thio-oxide phases. These materials crystallize in time sequence as the added amines decompose. Initially 2-D frameworks with composition (\left(\mathrm{Sn}{3} X{7}\right)^{2-}, X=\mathrm{S}) or (\mathrm{Se}) are produced. In the case of the sulfides these are shown to transform to 2-D and 3-D oxy-sulfides frameworks which incorporate the decomposed template. The structures of two materials in this sequence have been determined from single crystal X-ray diffraction. The first, (\mathrm{Sn}{3} \mathrm{Se}{7} \cdot \mathrm{C}{6} \mathrm{~N}{4} \mathrm{H}{16} \mathrm{CO}), designated TETN-SnSe-1, crystallizes after 1 day of digestion in space group (P b c a), with (a=23.553(6), b=) 14.004(6), and (c=13.967(4) \AA). The structure contains (\mathrm{SnSe}{5}) coordination polyhedra which form (\mathrm{Sn}{3} \mathrm{Se}{4}^{4+}) semicubes; six such semicubes are linked via (\mathrm{Se}{2}) bridges to form apertures in the (\mathrm{Sn}{3} \mathrm{Se}{7}^{2-}) sheet in (010). Similar structures occur in the TETN-SnS and TMA-SnS systems. The second material, with a framework designated SnOS-SB3, is formed after 5 days of digestion in either the TMA-SnS or TETN-SnS systems and crystallizes in C2/c, with (a=35.62(1), b=18.468(4), c=21.858(6) \AA), and (\beta=) 115.36(1) ({ }^{\circ}). The structure consists of tetrahedral clusters of composition (\left[\mathrm{Sn}{10} \mathrm{~S}{20} \mathrm{O}{4}\right]^{8-}), which are linked via single (\mathrm{S}) bridges at three corners to form a 2-D framework of composition (\left[\mathrm{Sn}{20} \mathrm{~S}{37} \mathrm{O}{8}\right]^{10-}). This is one member of a theoretical structural farrily with composition (\left[\mathrm{Sn}{10} \mathrm{~S}{20-n / 2} \mathrm{O}{4}\right]^{(8-n)-}), where (0 \leq n \leq 4) and represents the number of connections between clusters. 1995 Academic Press, Inc.