Uni-, bi-and ter-dentate complexes formed from PPh_2CH_2C(R)=NNHC(=O)Ph (R = Bu~t or Ph) and Pd or Pt: crystal structures of [PdCl{PPh_2CH_2C(Bu~t) =NN=C(Ph)O}], [Pt{PPh_2CH=C(Ph)NN=C(Ph)O{P_2CH_2C(Ph)=NNHC(=O)Ph}] and [Pd{PPh_2CH=C(Bu~t)NHNC)=O)Ph}_

摘要

Treatment of the phosphino-N-benozyl hydrazones PPh_2CH_2C(R)=NNHC(=O)Ph (R = Bu~t, I; R = Ph, II) with [MCl_2(NCPh)_2] (M = Pd or Pt) gave complexes of type [MCl{ppH_2ch_2c(Bu~t)=NN=C(Ph)O}] (M = Pd, 1; M = Pt, 2) containing two fused five-membered chelate rings. Metathesis with LiBr or NaI gave [MX{PPh_2CH_2C(Bu~t)=NN=C(Ph)O}] (X = Br or I; M = Pd or Pt). The complex [PtMe{PPh_2CH_2C(Bu~t)=NN=C(Ph)O}] (8) was obtained by treating [PtMe_2(cod)](cod = cycloocta-1,5-diene) with one equivalent of I in hot benzene. Treatment of [PtMe_2(cod)] with two eqivalents of the phosphine II gave [PtMe{PPh_2CH_2C(Ph)=NNC(=O)Ph}{PPh_2CH_2C(Ph)=NNHC(=O)Ph] (11), containing a six-membered chelate ring and a unidentate coordinated ligand II. Treatment of [PtCl_2(NCMe)_2] with two equivalents of II in the presence of triethylamine gave [Pt{PPh_2CH=C(Ph)N-N=C(Ph)O}{PPh_2CH_2C(Ph)=NNHC(=O)Ph] (12), containing a terdentate (P,N,O-bonded) doubly deprotonated ene-hydrazone ligand and a unidentate ligand II. Prolonged treatment of [PdCl_2(NCPh(_2] with two equivalents of I in the presence of triethylamine gave [Pd(PPh_2CH=C(Bu~t)NHNC(=O)Ph_2] (13), containing two chelated phosphino ene-hydrazide ligands forming six-membered rings. A similar platinum complex, [Pt{PPh_2CH=C(Bu~t)NHNC(=O)Ph}_2] (14), was synthesised. The terdentate complexes of [MX{PPh_2CH_2C(Bu~t)=NN=C(Ph)O}] (M = Pd, Pt; X = Cl, Me) underwent base-promoted (NEt_3) Michael-type reactions with MeO_2CC ident to CCO_2Me to give terdentate complexes of the type [MX{PPh_2CH[C(CO_2Me)=CH(CO_2Me)]C(Bu~t)=NN=C(Ph)O}] (M = Pd, Pt; X = Cl, Me). The corresponding bromides and iodides were made by metathesis. The crystal structures of 1, 12 and 13 have been determined.