A series of bis(O,O-dialkyldithiophosphato)zinc(11) complexes, ZnL2 (LH = (R0)2PS2H; R = Et, Pri, Bu, Bui, Bus, cyclohexyl), has been isolated. Pyridine adducts ZnL2(py)2 (R = Et, Pr, Pri, Bui) and ZnL2(py) (R = Pr, Pri, Bui) have also been obtained. Basic complexes ZnO,3ZnL2 (R = Et, Pr) have been isolated. Molecular weight data show that ZnL2 associates in benzene. When R = Pri 2ZnL2 ↔ Zn2L4 ΔG0c -6kJ mol-1 The adducts ZnL2(py) are stable. Adducts ZnL2(py)2 dissociate in benzene; when R = Pr ZnL2(py) + PY + ZnL2(py)2 ΔG0c-7kJmol-1 (ΔG0 calculated from molal concentrations). Infrared data cannot distinguish between chelate, bridging, and unidentate PS2 groups. Co-crystallization of ZnL2(py)2 and XiL2(py)2 could not be achieved, suggesting ZnL2(py)2 is cis-octahedral.