title: Mono- and dinuclear five-coordinate cyclometalated palladium(II) compounds.
abstract: Reaction of cyclometalated halide-bridged Pd(II) complexes 1-4 with the tertiary triphosphine ligand (Ph2PCH2CH2)2PPh (triphos) yielded complexes [((Ph2PCH2CH2)2PPh-P,P,P)Pd(N(Cy)=(H)C)C6H2(C(H)=N(Cy))Pd((Ph2PCH2CH2)2PPh-P,P,P)][ClO4]2 5, [Pd(C6H4-N=NC6H5)((Ph2PCH2CH2)2PPh-P,P,P)][ClO4] 6, and [Pd(R-C6H3C(H)=NCy)((Ph2PCH2CH2)2PPh-P,P,P)][ClO4] (7; R = 4-CHO, 8; 3-CHO). Spectroscopic and analytic data suggest five-coordination on the palladium atom, which, for complexes 5, 6, and 7, was confirmed by X-ray crystallography. The geometry around palladium may be view as a distorted trigonal bipyramid, with the palladium, nitrogen, and terminal phosphorus atoms in the equatorial plane. Compound 5 is the first doubly cyclometalated palladium(II) compound with two pentacoordinated metal centers. The structure of 6 comprises two discrete cations with slightly different geometries, showing the importance of crystal packing forces in order to determine the coordination arrangement.
authors.affiliation: Departamento de Química Fundamental, Universidad de La Coruña, E-15071 La Coruña, Spain.
authors.forename: M
authors.initials: M
authors.lastname: López-Torres
authors.forename: A
authors.initials: A
authors.lastname: Fernández
authors.forename: J J
authors.initials: JJ
authors.lastname: Fernández
authors.forename: A
authors.initials: A
authors.lastname: Suárez
authors.forename: M T
authors.initials: MT
authors.lastname: Pereira
authors.forename: J M
authors.initials: JM
authors.lastname: Ortigueira
authors.forename: J M
authors.initials: JM
authors.lastname: Vila
authors.forename: H
authors.initials: H
authors.lastname: Adams