COMPLEXES OF BINUCLEATING LIGANDS .11. SOME PALLADIUM(II) COMPLEXES OF A LIGAND CONTAINING A BRIDGING THIOPHENOXIDE COMPONENT

Binuclear palladium(II) complexes of the trianionic binucleating ligand (L3-), formally derived from 2-mercapto-5-methylisophthalaldehyde di-2′-hydroxyanil by loss of one mercapto and two phenolic protons, appear to present a significantly larger exchangeable bridging site than earlier binucleating systems containing a bridging phenoxide component. Thus LPd+2 is found to incorporate at this site a range of 'three atom bridges' as in, for example, PdOC-(CH3)OPd, PdNHC(C6H5)NHPd and PdP(C6H5)2CH2P(C6H5)2Pd and apparently some related H-bonded three atom bridges as in, for example, PdO(H)⋯H⋯N(H)(R)Pd. In one case, Na[LPd2(NO2)2]2H2O, it appears that two independent nitrite groups are bound at the normally bridging site (i.e. a 'non-bridged' system). However, LPd+2 will also incorporate 'two atom bridges', e.g. pyrazolate anion, neutral pyridazine, and a single nitrite ion bridging via N and O. Even 'one atom bridges' can be accommodated provided they are large enough, e.g. I-, Br-, but the corresponding chloro-bridged complex, LPd2Cl, could not be obtained. © 1979.