in toluene (N2); SnCl4 soln. added dropwise at -40°C to Sn complex soln. at1/4 molar ratio, warmed to room temp., stirred overnight, heated for 2 h at 80°C; evapd., hexane added, powder collected, dried (vac.); elem. anal.;

in toluene (N2); SnCl4 soln. added dropwise at -40°C to Sn complex soln. at1/4 molar ratio, warmed to room temp., stirred overnight, heated for 2 h at 80°C; evapd., hexane added, powder collected, dried (vac.); elem. anal.;

in toluene (N2); SnCl4 soln. added dropwise at -40°C to Sn complex soln. at1/4 molar ratio, warmed to room temp., stirred overnight, heated for 2 h at 80°C; evapd., hexane added, powder collected, dried (vac.); elem. anal.;