α,ω-bis(trichlorostannyl)alkanes as bis(monodentate) Lewis acids toward halide ions

Abstract

The reactions between X3Sn(CH2)nSnX3 (X = Cl, Br; n = 1, 3, 4, 8) and halide in solution are described. 119Sn NMR spectroscopy (CD2Cl2) indicates formation of five-coordinate dinuclear 1:2 adducts, [X4Sn(CH2)nSnX4]2-, with chloride and bromide. A trigonal-bipyramidal geometry has been confirmed in the solid state for the compound having X = Cl and n = 4. In contrast, fluoride reacts with X3Sn(CH2)nSnX3 to give six-coordinate tin species, [F5Sn(CH2)nSnF5].4- There was no evidence indicating that the tin atoms could act as a bidentate acid.