REACTIVITY OF CYCLOMETALATED COMPOUNDS OF N-BENZYLIDENEAMINES - SYNTHESIS AND X-RAY CRYSTAL-STRUCTURE OF [PD(1-CH2-2-(CH=N-C6H5)-3,5-(CH3)2C6H2) (2,4-ME2C5H3N)]CLO4

The action of Ph2PCH2CH2PPh2 (dpe) on the cyclometallated compounds [(Pd(C N)Br}2] (C N = 2-(HC=NC6H5)-5-ClC6H3 1a, 2-(CH2N=CH-2',6'-Cl2C6H3)C6H4 1b, or 1-CH2-2-(CH=N-C6H5)-3,5-(CH3)2C6H2 1c) in a 2:1 molar ratio, gives the novel neutral species [Pd(C N)Br(dpe)] (2a,b) or the ionic compound [Pd(C N)(dpe)]Br (3c). The action of dpe on compound 1 in a 1:1 molar ratio gives the dinuclear cyclometallated compound 4, in which two palladium atoms are bridged by the diphosphine. The ionic compounds [Pd(C N)(lut)(PPh3)]ClO4 6(lut = 2,4-lutidine) were obtained by reaction between AgClO4 and acetone solutions of the cyclometallated compounds [PdBr(C N)PPh3], and subsequent addition of 2,4-lutidine. [Pd(1-CH2-2-(CH=N-C6H5)-3,5-(CH3)2C6H2)(2,4-lut)]ClO4 crystallizes in the orthorhombic space group Pcab with a = 16.331(3) angstrom; b = 18.885(3) angstrom; c = 24.702(4) angstrom, and Z = 8. The endo six-membered ring displays a half-skew-chair conformation, with the palladium atom out of the plane (1.086 angstrom) defined by the other atoms.