Coordination Complexes of Tin(IV) Chloride with Unidentate Nitrogen Bases

Abstract

A single crystal X-ray study shows the product of reaction between quinuclidine, ‘qn’, and tin(IV) chloride in toluene solution to be, unusually, a five-coordinate neutral complex [qnSnCl₄]. Sn—N is 2.282(5) Å in an axial site of a trigonal bipyramidal array, trans to an Sn—Cl bond 2.367(2) with Sn—Cl (equatorial) 2.323(2)–2.333(2) Å. With 1,4-pyrazine, ‘pz’, as adumbrated by earlier spectroscopic work, a 1 : 2 (centro-symmetric) adduct, trans-[pz₂SnCl₄] is obtained (rather than a pyrazine bridged polymer) [Sn—N 2.246(1), Sn—Cl 2.3883(4), 2.3980(4) Å].