COMPLEXATION OF ORGANOTIN HALIDES WITH AMBIDENTATE, S, N, AND O DONOR LIGANDS

Eleven adducts derived from organotin halides of formula MeSnCl3 and R2SnCl2 (R = Me, Ph) were prepared with ligands containing N, 0, or S as possible bonding sites. X-ray crystal structure analyses for trichloromethyltin (IV)-l-methyl-2-(methylsulfinyl)imidazole (MeSnCl3.ImSOMe), trichloromethyltin(IV)-2-(n-propylsulfinyl)pyridine (MeSnCl3.PySOPr), and dichlorodimethyltin(IV)-1-methyl-2-(methylsulfinyl)imidazole(Me2SnCl2.ImSOMe) were determined. The MeSnCl3-ImSOMe complex crystallized in the space group P2(1)/n (No. 14) with a = 7.237 (4) angstrom, b = 14.074 (5) angstrom, c = 12.725 (5) angstrom, beta = 102.83 (3)-degrees, V = 1263.7 (8) angstrom3, Z = 4, and final R = 0.028 (R(w) = 0.032) for 2232 unique reflections. The MeSnCl3.PySOPr complex crystallized in space group P1BAR (No. 2) with a = 7.399 (2) angstrom, b = 8.740 (3) angstrom, c = 13.291 (4) angstrom, alpha = 95.47 (2)-degrees, beta = 100.25 (2)-degrees, gamma = 114.98 (2)-degrees, V = 752.5 (4) angstrom3, Z = 2, and final R = 0.042 (R(w) = 0.049) for 1959 unique reflections. The Me2SnCl2.ImSOMe complex crystallized in space group P1 (No. 1) with a = 6.985 (1) angstrom, b = 7.075 (1) angstrom, c = 7.320 (1) angstrom, alpha = 66.61 (2)-degrees, beta = 85.42 (2)-degrees, gamma = 87.94 (2)-degrees, V = 330.9 (1) angstrom3, Z = 1, and final R = 0.018 (R(w) = 0.022) for 1277 unique reflections. Whereas the molecular structures of MeSnCl3.ImSOMe and MeSnCl3.PySOPr show hexacoordination about tin, with the ligands binding both through nitrogen and the sulfinyl oxygen in a bidentate mode, in the Me2SnCl2.ImSOMe adduct the ligand is monodentate, forming an N-bonded, 5-coordinate complex. Proton and C-13 NMR data find these structures to be maintained in solution. NMR and IR data are presented for these and eight other adducts, finding that small changes in the Lewis acidity of the organotin chloride govern the coordination number and geometry about tin.