Reactivity of functionalised cyclometallated complexes of palladium(II). Crystal and molecular structure of [Pd{3-(CHO)C 6H 3C(H)NCy}(Br)(PEtPh 2)

Abstract

Treatment of the cyclometallated complexes [{Pd[3-(CHO)C 6H 3C(H)NCy}(X)} 2] [X=Cl ( 1), Br ( 2), I ( 3)] with tertiary monophosphines in a complex/phosphine 1:2 or 1:4 molar ratio afforded the halide-bridged cleaved [Pd{3-(CHO)C 6H 3C(H)NCy}(X)(L)] ( 6– 17) and non-cyclometallated complexes [Pd{3-(CHO)C 6H 3C(H)NCy}(X)(L) 2] ( 18– 23) (X=Cl, Br or I; L=PPh 3, PEtPh 2, PEt 2Ph or PMePh 2), respectively. Reaction of 6– 17 with cyclohexylamine in a complex/amine 1:1 or 1:2 molar ratio gave [Pd{3-(CyC(H)N)C 6H 3C(H)NCy}(X)(L)] ( 24– 28) and the non-cyclometallated [Pd{3-(CyC(H)N)C 6H 3C(H)NCy}(X)(L)(NH 2Cy)] ( 29– 32) complexes, respectively. Compounds 18, 19 and 22 gave [Pd{3-(CyC(H)N)C 6H 3C(H)NCy}(X)(PR 3) 2] ( 33– 35) with two uncoordinated CN groups, when treated with cyclohexylamine. Other reaction routes are also discussed. The complexes were characterised by their elemental analysis (C, H, N) and by IR and 31P{ 1H} and 1H-NMR data, and [Pd{3-(CHO)(C 6H 3C(H)NCy}(Br)(PEtPh 2)] ( 12) was characterised crystallographically.