Transition metal complexes with wide-angle dithio-, diseleno- and ditelluroethers: properties and structural systematics

The ligands o-C6H4(CH2EMe)2 (E = S or Se) have been prepared and characterised spectroscopically. A systematic study of the coordination chemistry of these, together with the telluroether analogue, o-C6H4(CH2TeMe)2, with late transition metal centers has been undertaken. The planar complexes [MCl2{o-C6H4(CH2SMe)2}] and [M{o-C6H4(CH2EMe)2} 2](PF6)2 (M = Pd or Pt; E = S or Se), the distorted octahedral [RhCl2{o-C6H4(CH 2EMe)2}2]Y (E = S or Se: Y = PF6; E = Te: Y = Cl) and [RuCl2{o-C6H4(CH 2EMe)2}2] (E = S, Se or Te), the dithioether-bridged binuclear [{RuCl2(p-cymene)}2{µ-o- C6H4(CH2SMe)2}] and the tetrahedral [M'{o-C6H4(CH2EMe)2} 2]BF4 (M' = Cu or Ag; E = S, Se or Te) have been obtained and characterised by IR and multinuclear NMR spectroscopy ( 1H, 63Cu, 77Se{1H}, 125Te{1H} and 195Pt), electrospray MS and microanalyses. Crystal structures of the parent o-C6H 4(CH2SMe)2 and seven complexes are described, which show three different stereoisomeric forms for the chelated ligands, as well as the first example of a bridging coordination mode in [{RuCl 2(p-cymene)}2{µ-o-C6H4(CH 2SMe)2}]. These studies reveal the consequences of the sterically demanding o-xylyl backbone, which typically leads to unusually obtuse E-M-E chelate angles of ~100°. © The Royal Society of Chemistry.