Phosphine transition metal complexes with

Non-phosphine type ligands are studied time by time with the aim to obtain water-soluble transition metal complexes with catalytic properties. However, with the exception of a few specific reaction types (e.g. oxidations) these catalysts cannot cope with tertiary phosphines - with the ligands on Figure 20 this has been found once again. 

Although the most versatile hydrogenation catalysts are based on tertiary phosphines there is a continuous effort to use transition metal complexes with other type of ligands as catalysts in aqueous systems some of these are listed in Table 3.3. 

This chapter is concerned with the effects of nonbonded interactions in tertiary phosphine-transition-metal complexes on (a) cyclometallation and C-H activation and (b) the stability and conformations of large chelate rings. It also deals with how nonbonded interactions might be used in other areas of chemistry. 

Structural and Magnetic Investigation on Transition Metal Complexes with Tripodal Polytertiary Phosphines... 

The possibility of using I3C-NMR spectroscopy to assist in assigning the geometry of bis-phosphine transition metal complexes has attracted the attention of several groups (80, 86-90). The examination of the PMR spectra of such complexes and analysis of the resulting AA XnXJ, spectra has proved valuable (91) but has the disadvantage that it is limited to systems in which the phosphorus atom is attached to methyl, methoxy, or methylene or to related groups in which the protons couple to phosphorus but not to other protons. The condition for the observation of a 1 2 1 triplet (usually associated with trans phosphine molecules) in the proton resonance spectrum is... 

An alternative strategy to a phosphine macrocycle involves template-assisted reaction of two coordinated bidentate secondary phosphines with two equivalents of a dielectrophile, to form tetradentate phosphine transition metal complexes, 60 (Scheme 23).44... 

The development of the catalytic hydrogenation system based on RhCl(PPh3)3 and methods for the resolution of optical isomers of tertiary phosphines occurred around the same time (1965), and this led to the possibility of asymmetric catalytic hydrogenation of prochiral unsaturated substances with C=C, C=0, and C=N bonds using transition metal complexes with chiral phosphine ligands. Such tertiary phosphines are of three types ... 

The catalysts for transfer hydrogenations are usually late transition metal complexes with tertiary phosphine ligands or bidentate nitrogen ligands, and the donors are usually organic compounds whose oxidation potential is sufficiently low to tolerate hydrogen transfer under mild conditions. Suitable donors are secondary alcohols such isopropanol. This alcohol is the most convenient since it is stable, non-toxic, environmentally friendly, easy to handle (bp 82°C), inexpensive and dissolves many organic compounds. 

Booth, G., Advan. Inorg. Chem. Radiochem. 6, 1 (1964) (transition-metal complexes with phosphines, arsines, and stibines). 

A variety of transition-metal complexes with Schiff base tertiary phosphines, (64)-(68) (Scheme 5), are known, including those of Cr,125 Mo,125,126 131 W,12 Ru,132 Ni, 24,127,128... 

Like H and 13C, the 31P nucleus has a spin of Vi. It is also the only stable isotope of phosphorus. Furthermore, the 31P chemical shift is highly sensitive to chemical structure and its chemical shift range is broad. As a consequence of these features, 31P NMR spectroscopy has had broad applications in the study of complexes of phosphines and other phosphorus-containing ligands. A recent review provides a variety of examples, including spectral analyses, of applications of 31P and 13C NMR to transition metal complexes with phosphorus-containing ligands.44... 

Syntheses, reactions, and biological activity of pyridine oximes 03KGS963. Transition metal complexes with 2,2 -bipyridines, pyridine-phosphines, and pyridine A-oxides as ligands 04IZV1733. 

More recently, the application scope of thermoregulated phase-separable transition metal complex with nonionic phosphine ligand has been expanded from hy-droformylation to hydrogenation, and the central metal varied from Rh to Ru. The first experimental study is the hydrogenation of styrene catalyzed by thermoregulated phase-separable Ru3(CO)12/PETPP complex catalyst. Under the conditions of Ph2 = 2.0 MPa, T=90°C, catalyst/substrate (mol/mol) = 1/1000, 3 hours, the Ru3(CO)12/PETPP complex catalyst exhibited good activity (Table 5). Compared with other catalysts, Ru3(CO)12/PETPP complex showed the same catalytic activity compared to the lipophilic Ru3(CO)9(TPP)3, while the hydrophilic Ru3(CO)9-(TPPTS)3 and Ru3(CO)9(TPPMS)3 are less active (Table 6). 

Phosphine ligands, including P-heterocyclic entities, are often used in transition metal complexes. The phosphole derivatives are the most widely used heterocyclic P-ligands. In this part the less known transition metal complexes with 6-ring phosphines are summarized. 

As the existence of this volume attests, transition metal complexes with phosphine ligands have proven to be useful and versatile catalysts for homogeneous reactions. Recently, binuclear metal complexes, particularly those with bridging phosphine ligands, have begun to attract interest because of their potential as catalysts and because of their novel structural... 

The preparation of (mera-sulfonatophenyl)diphenylphosphine, sodium salt in 1958 initiated the era of water-soluble transition metal complexes with tertiary phosphines as ligands. Water-soluble analogs of several prominent PPhj-containing complexes were synthesized with this ligand (commonly abbreviated as TPPMS) of which the preparations of RhCl(TPPMS)3, [RuCl2(TPPMS)2]2 and rra s-IrCl(CO)(TPPMS)2, are given in this section. ... 

An additional interesting physical property associated with perfluorinated phosphine transition metal complexes is fluorocarbon solubility. In contrast to the generally poor solubility of complexes with hydrocarbon ligand substituents in fluorocarbon media, (dfepe)Cr(CO)4 (68) and ((CF3)3P)xFe(CO)5 x (46) are moderately soluble in perfiuoroalkane solvents. While cw-(dfepe)2RuH2 (81) is only sparingly soluble in most polar and nonpolar solvents, it is substantially more... 

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