Reactivity of functionalised cyclometallated complexes of palladium(II).: Crystal and molecular structure of [Pd{3-(CHO)C6H3C(H)=NCy}(Br)(PEtPh2)]

Treatment of the cyclometallated complexes [{Pd[3-(CHO)C6H3C(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)C6H3C(H)=NCy}(X)(L)] (6-17) and non-cyclometallated complexes [Pd{3-(CHO)C6H3C(H)=NCy}(X)(L)(2)] (18-23) (X = Cl, Br or I; L = PPh3, PEtPh2, PEt2Ph or PMePh2), respectively. Reaction of 6-17 with cyclohexylamine in a complex/amine 1:1 or 1:2 molar ratio gave [Pd{3-(CyC(H)=N)C6H3C(H)=NCy}(X)(L)] (24-28) and the non-cyclometallated [Pd{3-(CyC(H)=N)C6H3C(H)=NCy}(X)(L)(NH2Cy)] (29-32) complexes, respectively. Compounds 18, 19 and 22 gave [Pd{3-(CyC(H)=N)C6H3C(H)=NCy}(X)(PR3)(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 P-31{H-1} and H-1-NMR data, and [Pd{3-(CHO)(C6H3C(H)=NCy}(Br)(PEtPh2)] (12) was characterised crystallographically. (C) 1998 Elsevier Science S.A. All rights reserved.