Pandey, Krishna K.; Lledos, Agusti published the artcile< Linear ME-Me Versus Bent M-E-Me: Bonding Analysis in Heavier Metal-ylidyne Complexes [(Cp)(CO)2MEMe] and Metallo-ylidenes [(Cp)(CO)3M-EMe] (M = Cr, Mo, W; E = Si, Ge, Sn, Pb)>, Name: ((2R,3S,4R,5R)-5-(6-Aminopurin-9-yl)-3,4-dihydroxy-oxolan-2-yl)methoxy-((((2R,3S,4R,5R)-5-(3-carbamoyl-4H-pyridin-1-yl)-3,4-dihydroxy-oxolan-2-yl)methoxy)hydroxyphosphoryl)oxyphosphinic acid disodium salt, the main research area is bonding analysis transition metal ylidyne complex.
The electronic and mol. structures of the complexes [(η5-C5H5)(CO)2MEMe] and [(η5-C5H5)(CO)3M-EMe] (M = Cr, Mo, W; E = Si, Sn, Pb) are calculated at the d.-functional theory (DFT) level using the exchange correlation functionals B3LYP and BP86. The theor. predicted bond lengths and angles of the model compounds are in excellent agreement with exptl. values. The calculations reveal the presence of a strong ME triple (σ + 2π) bond in [(η5-C5H5)(CO)2MEMe]. The M-E bond lengths in [(η5-C5H5)(CO)3M-EMe] are longer than those expected for a single bond. The nature of the MEMe and M-EMe interactions was analyzed with charge and energy decomposition methods. In the MEMe bond, the M-E σ-bonding orbitals are always polarized toward the silicon, tin, and lead atoms, and the polarization increases from chromium to tungsten. In contrast, in the M-EMe bond, the M-E σ-bonding orbitals are significantly polarized toward the metal atom. The hybridization at the metal atoms in the ME bonds has d character in the range 60.6-68.8%, while in the M-E bonds has large d character which is always >86% of the total AO contribution. In the complexes [(η5-C5H5)(CO)2MEMe], the contributions of the electrostatic interactions, ΔEelstat, and the covalent bonding, ΔEorb, have nearly the same values for silylidyne and germylidyne complexes, while for the stannylidyne and plumbylidyne complexes, the electrostatic interactions, ΔEelstat, are greater than the orbital interaction, ΔEorb. The covalent bonding has a high degree of π-character. The total interaction energy ΔEint in the compound [(η5-C5H5)(CO)3M-EMe] is less attractive than those in the complexes [(η5-C5H5)(CO)2MEMe]. The M-ER bonds have a slightly lower degree of covalent bonding (34.9-44.9%) than the MEMe bonds (42.1-50.2%). The drastic difference between the two classes of compounds are found for the degree of a” (π) bonding. The contribution of ΔEπ to the covalent term ΔEorb is much higher in the MEMe bonding (41.6-42.6%) than in the M-EMe bonding (17.1-20.4%). While the π bonding contribution in [(η5-C5H5)(CO)3M-EMe] are weaker than those in [(η5-C5H5)(CO)2MEMe], the σ-bonding contribution in the former compounds are stronger than those in the latter.
Inorganic Chemistry published new progress about Bond. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Name: ((2R,3S,4R,5R)-5-(6-Aminopurin-9-yl)-3,4-dihydroxy-oxolan-2-yl)methoxy-((((2R,3S,4R,5R)-5-(3-carbamoyl-4H-pyridin-1-yl)-3,4-dihydroxy-oxolan-2-yl)methoxy)hydroxyphosphoryl)oxyphosphinic acid disodium salt.
Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate