PHOSPHORANIMINE PHOSPHINES AND ARSINES AS HETERODIFUNCTIONAL COORDINATING LIGANDS - SYNTHESIS AND CHARACTERIZATION OF NEW PALLADIUM(II) METALLACYCLES RN=PPH2(CH2)NEPH2PDCL2 (R = SIME3, GEME3, H, N = 1, 2, E = P, AS) AND THE CRYSTAL AND MOLECULAR-STRUCTURE OF HN=PPH2CH2PPH2PDCL2, THE 1ST STRUCTURAL EXAMPLE OF A PHOSPHORANIMINE PHOSPHINE COMPLEX

Reaction of the N-(trimethylsilyl)- or N-(trimethylgermyl)phosphoranimine phosphines Me3ENPPh2CH2PPh2 (E = Si, Ge) or the N-(trimethylsilyl)phosphoranimine arsine Me3SiNPPh2CH2CH2AsPh2 with PdCl2(PhCN)2 gave metallacyclic PdII derivatives {formula-omited} (Q = P, n = 1, E = Si or Ge; Q = As, n = 2, E = Si). Water reacts with {formula-omited} to form the parent imine complex {formula-omited} (12), the structure of which has been determined. (Crystal data for 12 (as a 1:1 adduct with CH2C12): monoclinic P21/n (No. 14), a = 8.953 (3) Å, b = 21.151 (4) Å, c = 14.773 (2) Å, β = 93.98 (2)°, Z = 4, final R(F) = 0.034, Rw(F) = 0.037.) The imine ligand adopts an “envelope” five-membered chelate ring configuration bonded at N and P. The Pd—N (2.021 (6) Å) and N=P (1.599 (6) Å) bond lengths are in accord with expectations for Pd—N single and P=N double bonds. The nitrogen atom is pyramidal. 12 is also formed by reaction of Me3SiNPPh2CH2PPh2 with K2PdCl4 in the presence of water. Activated fluoroaromatics (e.g. pentafluorobenzonitrile) replace Me3Si or Me3Ge groups on the ligand framework by elimination of Me3SiF and attachment of the fluoroaromatic exclusively at the para position. Full spectral characterization of all complexes is given. The Me3Ge phosphoranimine phosphine shows conformational behavior similar to that of the Me3Si analogue reported earlier. All conformers in the mixture however give a metal complex with only one conformation. We also describe a more efficient synthesis of Me3GeN3, which was developed in the course of the study. © 1990, American Chemical Society. All rights reserved.