Nature of the bonding between silicon and the cobalt tetracarbonyl group in silyl cobalt tetracarbonyls

Theoretical Studies of the Bonding in Cationic Ruthenium Silylenes

“…The observed bond distances show that there is a preference for aliphatic ligands as substituents on the phosphines, while the use of electron-withdrawing groups at silicon only strengthens the Si−X bond at the expense of the Si−Ru bond. In short, while some degree of multiple bonding exists in all of the observed systems, it is low enough in many cases that it would not be incorrect to better describe these bonds as “augmented single” bonds, in a manner similar to that reported for M−SiR 3 bonds by previous workers …”

The electronic structure of cobalt complexes Co(CO)4GeCl3 and Co[Ge(C6H5)3](CO)3[P(C6H5)3]

“…The analysis of Co-М bonds in the Co(MX 3 )(CO) 4 complexes (M = Si, Ge, Sn and X = halide or organic groups), carried out by the 59 Co nuclear quadruple resonance method (NQR), confirmed a sufficient contribution of the π bonding to Co-Ge and Co-Sn in these compounds [2]. The existence of the π bonding in Co-Si in the Co(SiCl 3 )(CO) 4 complexes was also postulated in [3]. The electronic structure of the complex of the Co(CO) 4 MCl 3 type (M = Si, Ge) was considered previously in [4][5][6] based on the X-ray photoelectron spectroscopy (XPS) analysis and quantum chemical calculations.…”

“…The existence of the π bonding in Co-Si in the Co(SiCl 3 )(CO) 4 complexes was also postulated in [3]. The electronic structure of the complex of the Co(CO) 4 MCl 3 type (M = Si, Ge) was considered previously in [4][5][6] based on the X-ray photoelectron spectroscopy (XPS) analysis and quantum chemical calculations. The separate XPS lines of these compounds were interpreted, and the conclusion about the absence of π backdonation along the Сo-M bonds was drawn.…”

“…In order to examine in detail the electronic structure of the heteronuclear complexes with the Co-M bonds, we studied the electronic structure of the Co(CO) 4 GeCl 3 and Co[Ge(C 6 H 5 ) 3 ](CO) 3 [P(C 6 H 5 ) 3 ] complexes by X-ray emission spectroscopy and quantum chemical calculations based on the density functional theory. EXPERIMENTAL X-ray emission studies.…”

“…CoKβ 5 X-ray emission spectra(6) of Co(CO)4 GeCl 3 (left) and Co[Ge(C 6 H 5 ) 3 ](CO)3 [P(C 6 H 5 ) 3 ] (right) and the corresponding densities Co(p)(6), Co(s,d) (5), Ge(s,p) (4), С(s,p) (3), О(s,p) (2), Cl(s,p), and P(s,p) (1) states.intensities of the spectrum components are proportional to the degree of participation of the Co4p AO in the MOs of the compounds formed as a result of the chemical bonding of atoms. Since the Co4p contributions to the MOs of the complex are very small (several percent), so the disturbing effect of these AOs on the ligand MOs is also insignificant.…”