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

Abstract Treatment of the cyclometallated complexes [{Pd[3-(CHO)C 6 H 3 C(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 6 H 3 C(H)NCy}(X)(L)] ( 6 – 17 ) and non-cyclometallated complexes [Pd{3-(CHO)C 6 H 3 C(H)NCy}(X)(L) 2 ] ( 18 – 23 ) (X=Cl, Br or I; L=PPh 3 , PEtPh 2 , PEt 2 Ph 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 6 H 3 C(H)NCy}(X)(L)] ( 24 – 28 ) and the non-cyclometallated [Pd{3-(CyC(H)N)C 6 H 3 C(H)NCy}(X)(L)(NH 2 Cy)] ( 29 – 32 ) complexes, respectively. Compounds 18 , 19 and 22 gave [Pd{3-(CyC(H)N)C 6 H 3 C(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 31 P{ 1 H} and 1 H-NMR data, and [Pd{3-(CHO)(C 6 H 3 C(H)NCy}(Br)(PEtPh 2 )] ( 12 ) was characterised crystallographically.