Photoelectron Spectra of Phosphine Analogue Complexes of Co(CO)₃NO and CpMn(CO)₃

Abstract

The electronic structure of organometallic complexes with the phosphine analogue ligands trimethylarsine and trimethylstibine was studied. Four new complexes, CpMn(CO) 2 AsMe 3 , CpMn-(CO) 2 SbMe 3 , Co(CO) 2 NOAsMe 3 , and Co(CO) 2 NOSbMe 3 , were synthesized, and their He I and He II photoelectron spectra were recorded. The first ionization energies, which correspond to ionization from mainly metal d orbitals, are 6.83, 6.83, 7.58, and 7.69 eV, respectively. These numbers correspond to an approximately 1 eV uniform destabilization of the metal d orbitals, with respect to the parent carbonyls. The lone-pair orbital stabilization, with respect to the free ligands, was significant: 1.00, 0.94, 1.70, and 1.34 eV. The trends observed in these ionization energies were explained by the σand π-donor and π-acceptor properties of the ligands, on the basis of the changes in the hybridization of lone-pair orbitals.

Nitrogen, phosphorus, arsenic, antimony and bismuth

“…101 The photoelectron spectra of Mn(Z 5 -C 5 H 5 )(CO) 2 and Co(CO) 2 (NO) complexes of AsMe 3 and SbMe 3 have been reported. 102 The results demonstrate that s-donor ability decreased down the group, although net charge flow from the ligands remained essentially constant, consistent with back-donation which follows the same pattern. The coordination of stibine ligands to gold has been reported.…”

Manganese phosphinocarbodithioate for RAFT polymerisation with sunlight-induced chain end post-treatment

“…First, a well-known direct photochemical substitution of one carbonyl ligand in cymantrene with phosphine was attempted. [34][35][36][37][38] However, under the conditions previously optimized for PPh3, 38 the reaction selectivity was quite low and a tedious chromatographic purification was necessary to remove starting cymantrene and double substitution product Cp(CO)Mn(PPh2H)2 to provide the desired complex 3 only in ca. 50% yield.…”

Metal–Carbonyl Bond Energies in Phosphine Analogue Complexes of Co(CO)3NO by Photoelectron Photoion Coincidence Spectroscopy

“…Co(CO) 3 NO was obtained from Strem Chemicals, and no further purification was needed. Trimethylarsine and trimethylstibine were synthesized according to the literature. − Briefly, the appropriate trichloride was methylated using methylmagnesium iodide, which was prepared in an ether type solvent, to which the trihalide solution was added dropwise. Dibutyl ether was used in the case of AsMe 3 and diethyl ether in the case of SbMe 3 .…”

“…Bond dissociation energies (BDE) and heats of formation can be calculated and used to explain substituent effects; ,− however, measured dissociation energies are needed to test the validity of these results. Our groups have aimed to determine such BDE data systematically using photoelectron photoion coincidence spectroscopy (PEPICO) ,− and to explain the trends based on ultraviolet photoelectron spectroscopy (UPS). − …”

“…In this work, we present an imaging photoelectron photoion coincidence (iPEPICO) study on a series of trialkylpnictogen-substituted cobalt complexes, PMe 3 Co(CO) 2 NO, PEt 3 Co(CO) 2 NO, AsMe 3 Co(CO) 2 NO, and SbMe 3 Co(CO) 2 NO. Previously, we have published two preludes to this study: a threshold PEPICO (TPEPICO) paper on the two phosphine complexes and a more recent photoelectron spectroscopic study on all four title compounds . In the first paper, we also published the results of TCID experiments, carried out in the Armentrout lab, on the dissociation of the PR 3 Co + ions, as the TPEPICO experiments were limited by the available photon energy on the laboratory-based instrument.…”