New mixed ligand organotellurium(IV) compounds containing dithiocarbamatesand the more flexible imidotetraphenyldithiodiphosphinates. The crystal structures of C8H8Te(S2CNEt2)[SPPh2)(2)N]center dot H2O, C8H8Te(S2CNC5H10)[SPPh2)(2)N], and C8H8Te(S2CNC4H8S)[(SPPh2)(2)N]

The synthesis of the following mixed ligand organotellurium(IV) compounds C 8H8Te(S2CNEt2)[(SPPh2)(2)N].H2O (1), C8H8Te(S2CNC5H10)[(SPPh2)(2)N] (2), C8 H8Te-(S2CNC4H8O)[(SPPh2)(2)N] (3) and C8H8Te(S2CNC4H8S)- [(SPPh2)(2)N] (4) was achieved. They were characterized by IR, H-1, C-13, P-31 and Te-125 NMR , mass spectroscopy, and elemental analyses. The X-ray crystal structures o f 1, 2 and 4 were determined. The both types of ligands display an asymmetr ical chelating coordination mode on interaction with the tellurium atom. Wh en these aniso-bonded donor atoms are included in the coordination sphere, the tellurium atom exhibit an effective co-ordination number of seven. The arrangement may be described as 1:2:2:2 coordination with a presumably ster eoactive lone-pair of electrons.