Coordination Chemistry of the Antimony(III) and Bismuth(III) Cations using Bis(α-iminopyridine) as Ligand

Abstract

Bis(alpha-iminopyridine) L has been employed as the redox non-innocent Schiff-base ligand to coordinate with cationic antimony(III) and bismuth(III) centers. Mono- and di- cationic compounds: [LSbCl₂ ][CF₃ SO₃ ] 1, [LBiCl₂ ][CF₃ SO₃ ] 2, [LSbCl₂ ]₂ [Sb₂ Cl₈ ] 3, [LBiCl₂ ]₂ [Bi₂ Cl₈ ] 4, [LSbCl][CF₃ SO₃ ]₂ 5, [LBiCl][CF₃ SO₃ ]₂ 6 have been isolated and characterized using single crystal X-ray crystallography in the solid-state and solution-state NMR studies. These compounds have been prepared from PnCl₃ (Pn=Sb, Bi) and chloride abstracting agent such as Me₃ SiCF₃ SO₃ or AgCF₃ SO₃ in the presence of L. The Bi tri-cationic species forms heteroleptic compound 7, being coordinated by two types of Schiff-base donors L and L'. The latter has been in situ generated by the cleavage of one of the two imines present in L.

Keywords: Schiff base; antimony(III); bismuth(III); cation; coordination.