The X-ray crystal structures of (O,O-2,3-dimethylbutylene and O,O-2-dimethylpropylene dithiophosphato)diphenyltellurium(IV) derivatives, Ph2Te[S2POCMe2CMe2O]2 and 2Ph2Te[S2POCH2CMe2CH2O]2·2Ph2TeCl2·CS2 and those of (O,O-2,3-dimethylbutylene and O,O-2-dimethylpropylene dithiophosphoric acids, HS2POCM