Synthesis and Coordination Chemistry of a Novel Phosphinimine Phosphine

Abstract

The incorporation of a phosphinimino moiety into phosphine ligands to form a new bidentate Ph3P=N(CH&PPh2 (1) is reported. Compound 1 can act as a a-N and a-P donor ligand or react with metal carbonyls to form isocyanide complexes. Complexes of (COkM-(1-PJV) [M = Mo (2), W (3)l were prepared from the reaction of Et4N[M(C0)5Brl with 1 in refluxing THF solution, whereas the isocyanide complexes of (C0)5MCN(CH2)3PPh2 [M = Cr (4), Mo (5), W (6)] are obtained from the reaction of M(CO)6 with 1 at 25 "C. The deoxygenation nature is also shown in the reaction of CpFe(C0)21, CpRu(C0)21, Re(CO)sBr, and R e ~( C 0 ) ~o with 1 to form the corresponding isocyanide complexes [CpFe(CO){ CN(CHd3-PPhz-CQ}]I (71, C~RU(CO)I{CN(CHZ)~PP~Z-C) (lo), BrRe(CO),-,{ CN(CH2)3PPhz-C}, [n = 1 (12), 2 (14)], and R ~~( C O ) S { C N ( C H ~) ~P P ~~-C }(15), respectively. The free phosphine of 10 underwent exchange with one triphenylphosphine ligand in CpRu(PPh3)sCl to yield the binuclear species [CpRu(PPhs)Cl{ P(Ph2)(CH2)3NC}Ru(CO)CpI](l l), whereas intramolecular ligand substitution occurred in both 12 and 15 to give Br(CO)3Re{CN(CH2)3PPhz-C9) (13) and {pCN(CH2)3PPhz)Rez(CO)8 (16). Reaction of (COD)PdC12 with 1 produced the complex (1-PJV)PdC12 (18), in which 1 acts as a a-N, a-P bidentate ligand. X-ray crystal structural analysis of [CpFe(CO){ CN(CH2)3PPh2-C,P}]PF6 (7a) and 18 confirmed the formulation of both complexes. The C z N bond distance [1.20(3) A] of 7a is greater than those in the related iron-isocyanide complexes; the angle C-N-C [ 141( 2)"] deviates from MOO, indicating that the resonance contribution of Fe=C=N-is more important than that of Fe-CEN-. These observations are consistent with spectral data, the smaller infrared stretching wavenumber (2089 cm-l), and the greater shift (13C NMR 6 183.7 ppm) of the isocyanide moiety of 7.

Palladium(II) Complexes Containing a Pyridinyliminophosphorane Ligand

“…Recently, Stephan and Collins’ groups have reported independently that early transition metal complexes with phosphinimide ligands can catalyze the polymerization of ethylene 6,7. While the coordination studies involving iminophosphorane toward late transition metal complexes are well‐examined,4c,8−12 we would like to contribute our efforts in this area by investigating the behavior of palladium complexes with a series of bidentate pyridinyliminophosphorane ligands as well as their catalytic polymerization activity toward olefins.…”

Catalytic oxidation of anilines into azoxybenzenes on mesoporous silicas containing cobalt oxide

“…The composition of the resulting modified copolymer (EO-MA-N), determined by 1 H NMR integration, included a 0.25mole fraction of the azido group. Under anhydrous conditions, the copolymer reacted with triphenylphosphine to generate the iminophosphorane functionality [11,13], which was subsequently hydrolyzed to generate the amine function. Addition of CoCl 2 to an aqueous solution of the copolymer readily caused the color change from purple into blue, indicating the formation of its metal complex (EO-MA-Co).…”

Synthesis and catalysis of tungsten oxide in hexagonal mesoporous silicas (W-HMS)

“…Copolymer EO-MA-N (2.0 g) in THF (10 mL) was dried under vacuum and flashed with nitrogen gas. Triphenylphosphine (1.17 g, 4.4 mmol) in THF (3 mL) was added to the above solution at room temperature with stirring [16]. The mixture was stirred for overnight.…”

“…Infrared absorptions at 2100, 1746 and 1640 cm À1 is characteristic for stretching of -N 3 , C O of ester and C O of amide, respectively, which are further confirmed the functionalities of the copolymer. Under anhydrous conditions, the copolymer EO-MA-N was treated with triphenylphosphine to generate the iminophosphorane functionality [16], which subsequently reacted with W (CO) 6 to give the corresponding isocyanide complex EO-MA-W (Scheme 1). The presence of tungsten carbonyl complexes in copolymers was confirmed by IR spectrum.…”