Oxime-substituted NCN-pincer palladium and platinum halide polymers through non-covalent hydrogen bonding (NCN = [C 6H 2(CH 2NMe 2) 2-2,6] −)

Abstract

The oxime-substituted NCN-pincer molecules HON CH-1-C 6H 3(CH 2NMe 2) 2-3,5 ( 2a) and HON CH-4-C 6H 2(CH 2NMe 2) 2-2,6-Br-1 ( 2b) were accessible by treatment of the benzaldehydes H(O)C-4-C 6H 3(CH 2NMe 2) 2-3,5 ( 1a) and H(O)C-4-C 6H 2(CH 2NMe 2) 2-2,6-Br-1 ( 1b) with an excess of hydroxylamine. In the solid state both compounds are forming polymers with intermolecular O–H⋯N connectivities between the Me 2NCH 2 substituents and the oxime entity of further molecules of 2a and 2b, respectively. Characteristic for 2a and 2b is a helically arrangement involving a crystallographic 2 1 screw axis of the HON CH-1-C 6H 3(CH 2NMe 2) 2-3,5 and HON CH-4-C 6H 2(CH 2NMe 2) 2-2,6-Br-1 building blocks. The reaction of 2b with equimolar amounts of [Pd 2(dba) 3 · CHCl 3] ( 3) (dba = di benzylidene acetone) or [Pt(tol) 2(SEt 2)] 2 ( 4) (tol = 4-tolyl) gave by an oxidative addition of the C–Br unit to M coordination polymers with a [(HON CH-4-C 6H 2(CH 2NMe 2) 2-2,6)MBr] repeating unit ( 5: M = Pd, 6: M = Pt). Complexes 5 and 6 are in the solid state linear hydrogen-bridged polymers with O–H⋯Br contacts between the oxime entities and the metal-bonded bromide.