2,2'-azobisisobutyronitrile in melt (N2); heating a melt of tin compd. with ligand and AIBN to 140°C for 1 h; cooling, column chromy. (SiO2, gradient petroleum ether/CH2Cl2); elem. anal.;

in chloroform dropwise addn. of a soln. of Br2 in CHCl3 to a soln. of tin compd. in CHCl3 at 0°C, stirring for 24 h; evapn., recrystn. (petroleum ether); elem. anal.;

in chloroform dropwise addn. of a soln. of I2 in CHCl3 to a soln. of tin compd. in CHCl3 at 0°C, stirring for 24 h; evapn., recrystn. (petroleum ether); elem. anal.;