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Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C 6 H 5) 3 and often abbreviated to P Ph 3 or Ph 3 P. It is versatile compound that is widely used as a reagent in organic synthesis and as a ligand for transition metal complexes, including ones that serve as catalysts in organometallic chemistry.
Trifluorophosphine (PF 3) is a strong π-acid with bonding properties akin to those of the carbonyl ligand. [8] In early work, phosphine ligands were thought to utilize 3 d orbitals to form M-P pi-bonding, but it is now accepted that d-orbitals on phosphorus are not involved in bonding. [ 9 ]
The metal–ligand bond can be further stabilised by a formal donation of electron density back to the ligand in a process known as back-bonding. In this case a filled, central-atom-based orbital donates density into the LUMO of the (coordinated) ligand. Carbon monoxide is the preeminent example a ligand that engages metals via back-donation.
This structure is typical for four-coordinate 18 e − complexes. [2] The corresponding complexes Ni(PPh 3 ) 4 and Pt(PPh 3 ) 4 are also well known. Such complexes reversibly dissociate PPh 3 ligands in solution, so reactions attributed to Pd(PPh 3 ) 4 often in fact arise from Pd(PPh 3 ) 3 or even Pd(PPh 3 ) 2 .
Skeletal formula of a generic diphosphine ligand. R represents a side chain.The phosphine donors are connected by a backbone linker. Diphosphines, sometimes called bisphosphanes, are organophosphorus compounds most commonly used as bidentate phosphine ligands in inorganic and organometallic chemistry.
According to single crystal X-ray diffraction the compound adopts a slightly distorted square planar structure. [7] In analyzing the bonding, it is a complex of Rh(I), a d 8 transition metal ion. From the perspective of the 18-electron rule, the four ligands each provides two electrons, for a total of 16-electrons.
Ligand-modified versions of Stryker's reagent have been reported. By changing the ligand to, e.g., P(O-iPr) 3 the selectivity can be improved significantly. [ 8 ] In addition, Lipshutz et al., have shown that the addition of a bidentate, achiral bis-phosphine ligand on the Cu center can lead to substrate-to-ligand ratios typically on the order ...
This is the first example for a coordination compound of (phenylazo)thiolate ligand. The mechanism of formation of orthometalated azobenzene derivative was described to proceed via initial coordination of azo-nitrogen followed by electrophilic substitution at the pendant phenyl ring. PPh 3 plays a crucial role in the C(sp 3)−S cleavage process.