Preparation, structure and optical properties of [CH/sub 3/SC(NH/sub 2/)/sub 2/]/sub 3/SNI/sub 5/, [CH/sub 3/SC(NH/sub 2/)/sub 2/][HSC(NH/sub 2/)/sub 2/]SnBr/sub 4/, (CH/sub 3/C/sub 5/H/sub 4/NCH/sub 3/)PbBr/sub 3/, and [C/sub 6/H/sub 5/CH/sub 2/SC(NH/sub 2/)/sub 2/]/sub 4/P/sub b3/I/sub 10/