Donor Properties of Diphosphine Ligands in Tungsten Carbonyl Complexes:  Synchrotron Radiation XPS Measurements and DFT Calculations

Abstract

Synchrotron radiation XPS measurements of W 4f and P 2p core level binding energies in the series W(CO)4(P−P) (P−P = dppm (1), dppe (2), dppp (3), dppb (4), dmpe (5), F-dppe (6); dppm = bis(diphenylphosphino)methane, dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, dppb = 1,4-bis(diphenylphosphino)butane, dmpe = 1,2-bis(dimethylphosphino)ethane, F-dppe = 1,2-bis(bis(pentafluorophenyl)phosphino)ethane) are reported. The results are interpreted in terms of effects of the chelate ring size and of the nature of substituents of the P atoms. The trend of XPS data show an excellent agreement with the results of DFT calculations, obtained by the ΔSCF approach. Further analysis of the Kohn−Sham eigenvalues calculated at the ground-state level has assessed the role played by the initial state effects.

Electrochemical behaviour and structure of novel phosphine- and phosphite-substituted tungsten(0) Fischer carbene complexes

“…The σ-donor, π-acceptor [8] and steric [9] characteristics of phosphines can be regulated by modification of their substituents. Phosphines have many applications in organometallic chemistry, specifically as ligands in homogenous catalysts [10].…”

A versatile approach for the immobilization of amines via copper-free “click” reaction between azido self-assembled monolayer and alkynyl Fischer carbene complex. Application to the detection of staphylococcal enterotoxin A antibody

“…35 eV. Two components were obtained by curve-fitting at higher binding energy than that reported for a series of W(CO) 4 (LeL) complexes for which the main W 4f 7/2 peak was found around 31e32 eV [17]. Thus combination of three surface analysis methods gave evidence for the formation of azido-terminated SAM at the surface of gold and further attachment of alkoxycarbene entities to the SAM by click chemistry.…”

Relativistic frozen core potential scheme with relaxation of core electrons

“…For dppe, the shift is smaller than that of dmpe because of the screening capability of a core hole in the ligands. The π electrons of the phenylphosphine group are likely polarized in comparison with the σ electrons of the methylphosphine group, which leads to easy screening of core holes [47]. For F-dppe, the pentafluorophenylphosphine group includes highly electronegative F, and thus the electron density at W decreases.…”