Synthesis and a crystal structure analysis of mixed bis(phosphino)methanide/phosphonium bis(methylide) complexes of nickel, palladium, and platinum

Abstract

From bis(dipheny1phosphino)methanide complexes of the type /[(C,H5),Pl2CHJ2M (M = Ni, Pd, Pt), and an equivalent amount of an ylide R,(CH,)P = CH2 (R = CH,, C,H5), the three title, is the by-product of the reaction. An X-ray diffraction study of the platinum compound 5c revealed a mixed chelate structure with a planar bis@hosphino)methanide and a folded ylide ring. The central carbon of the bis(phosphin0)methanide is not in close contact with the metal. Its distances to the phosphorus atoms indicate significant double bond character, some of which is also retained in the phosphonium bis(methy1ide) group. It is more than ten years since Issleib and coworkers first showed that the bis(dipheny1phosphino)methanide anion 1 with its carbanionic centre between two phosphane donors is a very strong ligand to transition metals. Such complexes, however, were difficult to characterize due to their low solubility'), and with very few exceptions, this important result has not been exploited any further2*,). It was only in the case of the copper(1) derivative that the solid state structure could be determined by X-ray diffraction2). The ligands in this complex, shown to be a trimer, were found to be bridging two-and three-coordinate copper atoms such that both phosphorus atoms and the central carbanion were involved in coordinative bonding.

Synthesis and coordination chemistry (with platinum(II) and molybdenum(0)) of new bis (bis(trifluoromethyl)phosphano)alkanes. Structure of a new bis(phosphano) methanide complex

“…Preparation of the Molybdenum Complexes (35)(36)(37). Typically chloroform solutions (0.5 mL) containing 0.4 mmol each of m-[Mo(CO)4-(piperidine)2] and bis(phosphano)alkane (1, 2, or 24) were heated to 80 °C for 1 h in sealed 5-mm NMR tubes.…”

Structure of a homoleptic bis(diphenylphosphino)methanide complex, [Pt{(C6H5)2PCHP(C6H5)2}2].C6H6

“…"CH...P ring is formed in which the charge is delocalized over the two P-C bonds, or, alternatively, a three-membered Mpr-"S'~-H-P ring is obtained (Schmidbauer, Lauteschl~iger & MilewskiMahrla, 1983). The former arrangement is found in (1) and also in [Pt{(C6H5)2PCHP(C6H5)2}{(CH2) 2-P(CH3)2}] (2) (Bassett et al, 1980) and [PtCI(PEt3)-{(C6Hs)2PCHP(C6Hs)2}] (3) (Browning, Bushnell & Dixon, 1980). However, there are significant differences in geometry between the PtPEC chelate rings in (1)-(3).…”

Platinum organometallic compounds: classification and analysis of crystallographic and structural data. Part I. Monomeric Pt(0) and partly of Pt(II) with PtC4, PtA3B and PtC2A2 chromophores

“…There are seven derivatives (Christian et al 1978, Basset et al 1980, Carr et al 1988, Crascall et al 1990, McCrindle et al 1990, Mole et al 1991, Edelbach et al 1998b in which a pair of homo-bidentate − C,C ′ and − P,P ′ donor ligands form a cis -square planar environment about each Pt(II) atom (PtC 2 P 2 ). In three of the derivatives (Carr et al 1988, Crascall et al 1990, Mole et al 1991 ), a homo-bidentate − C,C ′ donor atom ligand creates four-membered metallocycles with a mean C − Pt − C bite angle of 40.5 ° .…”

“…In a yellow derivative (Basset et al 1980 ), the homo-bidentate CH 2 P(Me 2 )CH 2 dianion forms a four-membered metallocycle (-CPC-) with a C − Pt − C bite angle of 73.9(7) ° , and the dppm ligand also forms a four-membered metallocycle with a P − Pt − P bite angle of 69.6(2) ° .…”