New 2,4,6-trinitrophenylpalladium(II) complexes. Crystal and molecular structure of tram-2,4,6 trinitrophenyl(chloro)bis(triphenylarsine)palladium(II)

Abstract

The complex Q2[Pd,R,C1,(p-Cl),] (Q = (PhCH*)PPh,; R = 2,4,6-trinitrophenyl) reacts with PPh, or AsPh, in molar ratio l/2 to give the dinuclear complexes [Pd,R&-Cl&]. Complexes of the type [Pd(R)CIL,] (L= PPh3, AsPh,, SbPh3, tetrahydrothiophene (tht) or L = 1,2-bis(diphenylphosphino)- ethane (dppe), 1,kyclooctadiene (COD), 2,2’-bipyridine (bipy), 2,2’-biquinolyl (bquin), l,lO-phenanthroline (phen), 2,9-dimethyl-l,lO-phenanthroline (Me,phen)) have been obtained using the stoichiometric amounts, or an excess, of the corresponding ligands. The complex [Pd(R)Cl(py)2] (py = pyridine) could only be isolated starting from those with L= tht or L= COD. The crystal structure of [Pd(R)Cl(AsPh&] has been determined by X-ray diffraction methods. Crystals are monoclinic, space group P&/c, a = 14.214(4), b = 20.588(6), c= 14.295(4) A, p= 104.94(2)“, V=4042(2) R, Z=4. The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares to R=0.720 for 2455 observed reflections. In the square planar coordination around the Pd atom the two AsPh, ligands are in trans positions and the 2,4,6_trinitrophenyl ligand acts as monodentate through a carbon atom with the phenyl ring nearly perpendicular to the coordination plane