Preparation, stereochemistry, and crystal structures of some complexes of the macrocycle 3,3,7,7,11,11,15,15-octamethyl-1,9-dithia-5,13-diazacyclohexadecane with CoII, NiII, CuI, CuII, ZnII, RhIII, AgI, CdII, PtII, and HgII salts