Hapticity of asymmetric rhodium-allyl compounds in the light of real-space bonding indicators

Rhodium boryl complexes are valuable catalysts for hydro- or diboration reactions of alkenes, but can also react with ketones (R2C=O) and imines (R2C=NR′) giving rise to insertion products having formally Rh–R2C–O/NR′–B linkages. The resulting molecular structures, however, may show complex metal–ligand and ligand–ligand interaction patterns with often unclear metal–ligand connectivities (hapticities, ηn). In order to assign the correct hapticity in a set of asymmetric rhodium-allyl compounds with molecular structures indicating η1−5 bonding, a comprehensive DFT study was conducted. The study comprises determination of a variety of real-space bonding indicators derived from computed electron and pair densities according to the AIM, ELI-D, NCI, and DORI topological and surface approaches, which uncover the metal–ligand connectivties and suggest an asymmetric ligand–metal donation/metal–ligand back-donation framework according to the Dewar–Chatt–Duncanson model.

Polyfunctional Anion Exchangers on the Basis of Allyl Compounds, Glyсydilic Ethers of Dioxybenzenes and Some Di- and Polyamines

Scientific basis for preparation of new carbon-mineral adsorbents, supports, highly selective catalysts, and composite materials synthesized by a carbide cycle mechanism on the finely disperse particles of the iron subgroup metals, their alloys with some other metals is discussed. It was found that the carbide cycle mechanism involves the chemical and physical steps. The regularities of the process performance on the both stages are considered. Graphite filaments may be formed of graphite layers with either coaxial-cylindrical, coaxial-conic or stack orientations in the filament body. A number of primary and secondary properties of the graphite aggregates is being discussed. We have developed the methods for control the synthesis of carbon-mineral materials of the specified properties by varying the parameters of the metal particles, the nature of hydrocarbon decomposition, and the process mode.

Stabilization of η3-indenyl compounds by sterically demanding N,N-chelating ligands in the molybdenum coordination sphere

A series of η3-indenyl molybdenum compounds, isostructural with the well-known η3-allyl compounds, was synthesized from the recently established synthon [{(η5-4,7-Me2C9H5)Mo(CO)2(μ-Cl)}2].