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This article describes a density functional theory (DFT) study to explore a bio‐inspired NiFe complex known for its experimental activity in electro‐reducing CO2 to CH4 when adsorbed on graphite. The coordination properties of the complex are investigated in isolated form and when physisorbed on a graphene surface. A comparative analysis of DFT approaches for surface modeling is conducted, utilizing either a finite graphene flake or a periodic carbon surface. Results reveal that the finite model effectively preserves all crucial properties. By examining predicted structures arising from CO2 insertion within the mono‐reduced NiFe species, whether isolated or adsorbed on the graphene flake, a potential species for subsequent electro‐reduction steps is proposed. Notably, the DFT study highlights two positive effects of complex adsorption: facile electron transfers between graphene and the complex, finely regulated by the complex state, and a lowering of the thermodynamic demand for CO2 insertion. [ABSTRACT FROM AUTHOR]

Pyrido[4,3,2-KI] acridines represent a new class of heterocycles and isomers of marine alkaloids. Molecular calculations were found to account for the observed regioselectivity.

Research has been conducted on the 4-pentenyl, 5-hexenyl, 6-heptenyl, and 7-octenyl fluorinated and ether radicals. The cyclization reactions of these radicals have been conducted via the hybrid Hartree-Fock density functional method and the results are discussed.

Density functional methods were used to examined alkyne-dicobalt hexacarbonyl compounds, to determine electronic differences and their role in regiochemical outcomes.

Research has been conducted on the acylation reaction regioselectivity. The results indicate that regioselectivity of the Vilsmeier-Haack reaction can be explained by the stability of the cationic intermediate resulting from the attack on C (sub)4.

The reaction of methanimine with hydrogen cyanide is reported.

A study has been conducted to examine the application of the symmetry-adapted perturbation theory to characterize the pair and non-additive interactions in water clusters. Experiments involved close scrutiny of the structures corresponding to the global minima and transition states of the trimer that govern the hydrogen bond rearrangement. Findings indicate the all of the used density functional methods fail to correctly describe the three-body interactions in the water trimer.

Herein, a new heterobimetallic CoFe complex is reported with the aim of comparing its performance in terms of H2 production within a series of related MFe complexes (M = Ni, Fe). The fully oxidized [(LN2S2)CoII(CO)FeIICp]+ complex (CoIIFeII, LN2S2 2− = 2,2′-(2,2′-bipyridine-6,6′-diyl)bis(1,1′-diphenylethanethiolate), Cp− = cyclopentadienyl anion) can be (electro)chemically reduced to its CoIFeII form, and both complexes have been isolated and fully characterized by means of classic spectroscopic techniques and theoretical calculations. The redox properties of CoIIFeII have been investigated in DMF, revealing that this complex is the easiest to reduce by one-electron among the analogous MFe complexes (M = Ni, Fe, Co). Nevertheless, it displays no electrocatalytic activity for H2 production, contrary to the FeFe and NiFe analogs, which have proven remarkable performance. [ABSTRACT FROM AUTHOR]

The mechanism of the metathesis reactions of sigma-bond of water and alcohols with palladium hydrochloride and methyl complexes was established. An additional lone pair not involved in any reaction has caused a lowering of the transition state of the orbitals secondary to the rehybridization effect of the nonreacting pair. Furthermore, the reactions were determined by the electrostatic charges of the reacting entities.

The study rationalizes for the first time the experimentally observed reactivity differences of cyclohexene, cylopentene and norbornene. The reactivity of different Co2(CO)6-acetylene complexes in the Pauson-Khand reaction is found to be strongly dependent on the nature of the olefin.

Examines the applicability of various density functional theory (DFT) methods to describe the anisotropy of the intermolecular potential energy surfaces of hydrogen-bonded and van der Waals complexes. Comparison between supermolecule coupled-cluster method and perturbational symmetry-adapted perturbation theory.

Presents a theoretical study of the OH[sup -]H[sub 2]O)[sub 2] system and the nature and importance of nonadditive three-body interactions. Account on the supermolecule Moller-Plesset (MP) perturbation theory; Details on the symmetry-adapted perturbation theory (SAPT); Comparison of the MP and SAPT convergence.

The description of the electric properties of the subsystems and effect of the basis set superposition error (BSSE) correction on the geometry of the full system was examined using the intermolecular interaction field. The study revealed that the BSSE was large with the diffuse basis sets that were needed for accurate polarizability and the uncorrected geometry underestimated the intermolecular distance and overestimated the length of the water OH bond involved in the H-bond.

It has been possible to make a detailed B3LYP investigation of the regiochemistry-determining event in the Pauson-Khand reaction (PKR). It is concluded that productive axial coordination of an olefin must be taken into account in both theoretical and synthetic PKR studies.