In homogeneous catalysis, the catalyst is in the same phase as the reactant. The number of collisions between reactants and catalyst is at a maximum.In a patent, 244261-66-3, name is (R)-5,5′-Bis(diphenylphosphino)-4,4′-bibenzo[d][1,3]dioxole, introducing its new discovery. Safety of (R)-5,5′-Bis(diphenylphosphino)-4,4′-bibenzo[d][1,3]dioxole
As the workhorses for many applications, neutral dimeric mu2-X-bridged diphosphine rhodium complexes of the type [{Rh(diphosphine)(mu2-X)}2] (X = Cl, OH) are usually prepared in situ by the addition of diphosphine ligands to the rhodium complex [{Rh(diolefin)(mu2-X)}2] (diolefin = cyclooctadiene (cod) or norbornadiene (nbd)) or [{Rh(monoolefin)2(mu2-Cl)}2] (monoolefin= cyclooctene (coe) or ethylene (C2H4)). The in situ procedure has been investigated for the diphosphines 2,2?-bis(diphe-nylphosphino)- 1,1?-binaphthyl (BINAP), 5,5?-bis(diphenylphos-phino)- 4,4?-bi-1,3-benzodioxole (SEGPHOS), 5,5?-bis[di(3,5-xylyl)- phosphino]-4,4?-bi-1,3-benzodioxole (DM-SEGPHOS), 5,5?- bis[di(3,5-di-tert-butyl-4-methoxyphenyl)phosphino]-4,4?-bi-1,3- benzodioxole (DTBM-SEGPHOS), 2,2?-bis(diphenylphosphino)- 1,1?-dicyclopentane (BICP), 1-[2-(diphenylphosphino)ferrocenyl] ethyldi-tert-butylphosphine (PPF-PtBu2), 1,1?-bis(diisopropylphosphino) ferrocene (DiPPF), 1,2-bis(diphenylphosphino)-ethane (DPPE), 1,2-bis( o-methoxyphenylphosphino)ethane (DIPAMP), 4,5-bis(diphenylphosphinomethyl)-2,2-dimethyl-1,3- dioxalane (DIOP), 1,2-bis(2,5-dimethylphospholano)benzene (Me-DuPHOS), 1,4-bis(diphenylphosphino)butane (DPPB), and 1,3-bis(diphenylphosphino)propane (DPPP); the resulting complexes have been characterized by 31P NMR spectroscopy and, in most cases, also by X-ray analysis. Depending on the diphosphine ligand, the solvent, the temperature, and the rhodium precursor, species other than the desired one [{Rh(diphosphine)(mu2-X)}2] are formed, for example, [(diolefin)Rh(mu2-Cl)2Rh(diphosphine)], [Rh(diphosphine)- (diolefin)]+, [Rh(diphosphine)2]+, and [Rh(diphosphine)- (diolefin)(Cl)]. The results clearly show that the in situ method commonly applied for precatalyst preparation cannot be regarded as an optimal strategy for the formation of such neutral [{Rh(diphosphine)(mu2-X)}2] complexes.
The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 244261-66-3 is helpful to your research. Safety of (R)-5,5′-Bis(diphenylphosphino)-4,4′-bibenzo[d][1,3]dioxole
Reference£º
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI