Di(imino)aryltin(iv) dichlorides as tectons for heterometallic coordination compounds

Abstract

Hydrolysis of [2-{(CH2O)2CH}C6H4]2SnCl2 (1) [prepared from 2-[(CH2O)2CH]C6H4MgBr and SnCl4, in 2 : 1 molar ratio] gave [2-(O=CH)C6H4]2SnCl2 (2). Treatment of with the appropriate amine, in the absence of a solvent or catalyst, resulted in the isolation in high yields of [2-(RN[double bond, length as m-dash]CH)C6H4]2SnCl2 [R = 2'-C10H7 (3), 2',4',6'-Me3C6H2 (4), PhCH2 (5), Me2NCH2CH2 (6), 2'-PyCH2 (7)]. The reaction of with [Pd(COD)Cl2] provided the heterometallic species [Cl2Pd{2-(2'-PyCH2N[double bond, length as m-dash]CH)C6H4}2SnCl2] (8). The compounds were characterised by multinuclear NMR spectroscopy in solution, and mass spectrometry and IR spectroscopy in the solid state. The molecular structures of 1, 2, 4-7 and 8·CH3CN were established by single-crystal X-ray diffraction. For all diorganotin(IV) dichlorides intramolecular O→Sn or Nimine→Sn coordination results in hypercoordinated species with a distorted octahedral (C,E)2SnCl2 core (E = O, N). The presence of intramolecular N→Sn interactions in solution, responsible for the restriction of free rotation of mesityl groups around the C-N(=C) single bonds, is suggested by (1)H and (13)C NMR data. In the heterometallic dinuclear complex 8 the octahedral coordination around tin is preserved as in 7 and the nitrogen atoms from the pyridyl groups in the pendant arms are coordinated to palladium, leading to a trans-square planar PdCl2N2 core.