Theoretical insights on the encapsulated hydronium ion mediated supramolecular assembly of nickel(II) Schiff base complexes: Strong hydrogen bonded interaction due to charge transfer from the lone pair of oxygen to the antibonding orbital of the O-H bond

To understand the packing in a particular crystal we need to investigate the supramolecular interactions. Here we report a hydronium ion encapsulated within a dimeric assembly of two different nickel(II)...

Theoretical insights into the effect of the overpotential on CO electroreduction mechanisms on Cu(111): regulation and application of electrode potentials from a CO coverage-dependent electrochemical model

The electron transfer into the π antibonding orbital of CO leads to increasing overpotential and weaker CO bonding with the Cu surface.

DFT studies of two-electron oxidation, photochemistry, and radical transfer between metal centres in the formation of platinum(iv) and palladium(iv) selenolates from diphenyldiselenide and metal(ii) reactants

Excitation by light to the M–M antibonding orbital of [MIIIMe2(2,2′-bipyridine)(SePh)]2 releases 2[MIIIMe2(bipy)(SePh)]˙; the doublets react to give MIVMe2(bipy)(SePh)2 and MIIMe2(bipy).

A comparative computational study on hydrogen adsorption on the Ag+, Cu+, Mg2+, Cd2+, and Zn2+ cationic sites in zeolites

Three essential factors have been identified (i–iii) for the interaction between H2 and Ag+, Cu+, Mg2+, Cd2+, and Zn2+ sites in zeolites: (i) donation from σH2 to the cation, (ii) π-backdonation from the cation to antibonding orbital of the molecule, and (iii) the interaction between H2 and oxygen framework which is crucial for H2 dissociation on Zn2+ sites.

Investigation of hydrogen bonding between nitrosamine and sulfuric acid using Density Functional Theory

DFT calculations were performed to analyze those interactions; B3LYP and B3PW91 methods were applied and the following basis sets were used: 6-311++G(2d, 2p), 6-311++G(3df, 3pd) and aug-cc-pVDZ. The natural bond orbital (NBO) analysis and atom in molecules (AIM) theory were applied to understand the nature of the interactions. The most stable complex NS1 with an eight-membered cyclic structure contains two O- H· ··O and N-H·· ·O hydrogen bonding interactions. From the values of r(r) at O·· ·H critical points, it can be concluded that the H-boding in eight-membered cyclic NS1 is stronger than other. The elongation of the O-H bond length is caused by the electron-density transfer to the O-H antibonding orbital.

Electronic propensity of Cu(II) versus Cu(I) sites in zeolites to activate NO — Spin- and orbital-resolved Cu–NO electron transfer

Electronic factors responsible for the notable decline of NO activation by Cu(II) with respect to Cu(I) sites in zeolites are investigated within spin-resolved analysis of electron transfer channels between the copper center and the substrate. The results of natural orbitals for chemical valence (NOCV) charge transfer analysis for a minimal model of Cu(II) sites in zeolite ZSM-5 ({T1Cu}+ NO) are compared with those for Cu(I)–NO and referenced to an interaction of NO with bare Cu+ cations. The bonding of NO, which is an open-shell and non-innocent ligand, gives rise to a noticeable nondynamical correlation in the adduct with Cu(II) (reflected in a broken-symmetry solution obtained at the density functional theory (DFT) level). Four distinct components of electron transfer between the copper and NO are identified: (i) donation of an unpaired electron from the NO π∥* antibonding orbital to the Cu species, (ii) backdonation from copper d⊥ to the NO antibonding orbital, (iii) “covalent” donation from NO π∥ and Cu d∥ orbitals to the bonding region, and (iv) donation from the nitrogen lone pair to Cus,d. Large variations in channel identity and significance may be noted among studied systems and between spin manifolds: channel i is effective only in the bonding of NO with either a naked Cu+ cation or Cu(II) site. Channel ii comes into prominence only for the model of the Cu(I) site: it strongly activates the NO bond by populating antibonding π*, which weakens the N–O bond, in contrast to channel i depopulating the antibonding orbital and strengthening the N–O bond. Channels iii and iv, however, may contribute to the strength of the bonding between NO and copper, and are of minor importance for the activation of the NO bond. This picture perfectly matches the IR experiment: interaction with either Cu(II) sites or a naked Cu+ cation imposes a comparable blue-shift of NO stretching frequency, while the frequency becomes strongly red-shifted for a Cu(I) site in ZSM-5 due to enhanced π* backdonation.

Complexes of sulfuric acid with N,N-dimethylformamide: An ab initio investigation

The (H2SO4)2, H2SO4-DMF, and (H2SO4)2-DMF complexes have been investigated, using the B3LYP functional with cc-pVQZ basis set. The characteristics of structure and energetics for binary complexes of sulfuric acid with dimethylformamide (DMF) have been obtained for the first time. The H-bond formation both between molecules of sulfuric acid as well as sulfuric acid-DMF were studied, on the basis of Weinhold’s natural bond orbital (NBO) analysis. It was shown that the H-bond formation between sulfuric acid and DMF molecules is stronger than ones for the acids dimer. The value of charge transfer from lone pair (LP) orbitals of DMF oxygen to the antibonding orbital of acid OH-bond significantly exceeds the criterion of H-bond existance (0.01 e). As follows from energy, among the complexes under investigation the most preferable one was found to be (H2SO4)2-DMF in which sulfuric acid molecules are linked with each other by three H-bonds.