Five-coordinate Pd(II) orthometallated triarylphosphite complexes

• Published in: Dalton transactions : an international journal of inorganic chemistry no. 4; p. 459
• Main Authors: Bedford, Robin B, Betham, Michael, Butts, Craig P, Coles, Simon J, Cutajar, Marica, Gelbrich, Thomas, Hursthouse, Michael B, Scully, P Noelle, Wimperis, Stephen
• Format: Journal Article
• Language: English
• Published: England 01.01.2007
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/b613524b

The reaction of the orthopalladated triarylphosphite complexes [{Pd(mu-Cl){kappa(2)-P,C-P(OC(6)H(2)-2,4-R(2))(OC(6)H(3)-2,4-R(2))}(2)] (R = H, (t)Bu) with bis(2-diphenylphosphinoethyl)phenylphosphine leads to a five-coordinate palladium(II) (R = H) and a mixture containing four-and five-coordinate species (R = (t)Bu). The crystal structure of the five-coordinate species [Pd{kappa(2)-P,C-(P(OC(6)H(4))(OC(6)H(5))(2)}{bis(2-diphenylphosphinoethyl)phenylphosphine}][SbF(6)] is presented. This complex reacts with hydrogen peroxide or [AuCl(tht)] to give four-coordinate complexes in which the displaced phosphine residue is either oxidised or coordinated to gold chloride; this demonstrates that the five-coordinate complexes are labile in solution. By contrast, the reactions of the dimeric precursors with 1,1,1-tris(diphenylphosphinomethyl)ethane give four-coordinate complexes in the solid state, although evidence is presented that the smaller phosphite-containing system is five-coordinate at room temperature or higher in solution.