Crystal and molecular structures of three diimine adducts of diphenyltin dichloride

Abstract

The crystal structures of three diimine adducts of diphenyltin dichloride have been determined at room temperature. The colorless crystals of the adduct formed with 5-methylphenanthroline, [Ph₂SnCl₂(5-Mephen)], C₂₅H₂₀Cl₂N₂Sn, are monoclinic, space group P2₁/n with unit cell dimensions a = 9.393(5) Å b = 12.896(3) Å, c = 18.034(4) Å, β = 94.48(3)°, Z = 4 and D_x = 1.641Mg m⁻³. The yellow crystals of the 4,7-dimethylphenanthroline adduct, [Ph₂SnCl₂(4,7-Me₂phen)], C₂₆H₂₂Cl₂N₂Sn, are monoclinic, space group P2₁/n with unit cell dimensions a = 9.163(2) Å, b = 17.828(4) Å, c = 14.395(5) Å, β = 101.29(2)°, Z = 4 and D_x = 1.590Mg m⁻³. Yellow crystals of the 4,5-diazafluorene-9-one adduct, [Ph₂SnCl₂(4,5-diazafluorene-9-one)], C₂₃H₁₆Cl₂N₂OSn, are orthorhombic, space group Pbca with unit cell dimensions a = 16.239(2) Å, b = 16.673(2) Å, c = 16.058(2) Å, Z = 8 and D_x = 1.607Mg m⁻³. The structures were solved by direct methods and refined by a full-matrix least-squares procedure to final R = 0.043 using 2542 reflections for [Ph₂SnCl₂(5-Mephen)], R = 0.060 using 2521 reflections for [Ph₂SnCl₂(4,7-Me₂phen)], and R = 0.038 using 1919 reflections for [Ph₂SnCl₂(4,5-diazafluorene-9-one)]. The tin atoms in the three adducts exist in distorted octahedral geometries with the phenyl substituents occupying trans positions. An examinations of the derived parameters in the three structures shows that the two phenanthroline ligands have similar coordinating abilities towards Ph₂SnCl₂ and that these ligands are stronger Lewis bases than 4,5-diazafluorene-9-one.