DFT analysis of the interaction between Hg and monodentate neutral ligands using NBO, EDA, and QTAIM.

We report thermodynamic, geometric, and electronic parameters for the interaction between neutral ligands and the [Hg(HO)] dication, using the B3LYP/6-311 + G(d,p) approach. Gibbs free energies for the interaction were employed to rank the affinity order of the several neutral ligands. To identify the parameters that characterize the affinity between the two fragments, the metal-ligand interaction was analyzed according to the EDA, NBO, and QTAIM decomposition schemes.

A DFT study of the interaction between [Cd(HO)] and monodentate O-, N-, and S-donor ligands: bond interaction analysis.

A series of B3LYP/6-311+G(d,p) calculations of the affinity of monodentate ligands for [Cd(HO)] are performed. Three types of ligands containing O (phosphine oxide, lactam, amide, carboxylic acid, ester, ketone, aldehyde, ether, halohydrin, enol, furan), N (thiocyanate, amine, ammonia, azide), and S (thioester, thioketone, thiol, thiophene, disulfide) interacting atoms are investigated. The results show that phosphine oxide has the largest affinity for the cadmium cation due to the polarization of the P=O bond.

A density functional theory investigation of the interaction of the tetraaqua calcium cation with bidentate carbonyl ligands.

Calcium complexes with bidentate carbonyl ligands are important in biological systems, medicine and industry, where the concentration of Ca is controlled using chelating ligands. The exchange of two water molecules of [Ca(HO)] for one bidentate monosubstituted and homo disubstituted dicarbonyl ligand was investigated using the B3LYP/6-311++G(d,p) method. The ligand substituents NH, OCH, OH, CH, H, F, Cl, CN and NO are functional groups with distinct electron-donating and -withdrawing effects that bond directly to the sp C atom of the carbonyl group.

Computational study of the effect of dispersion interactions on the thermochemistry of aggregation of fused polycyclic aromatic hydrocarbons as model asphaltene compounds in solution.

Density functional theory (DFT), Møller-Plesset second-order perturbation theory (MP2), and semiempirical methods are employed for the geometry optimization and thermochemistry analysis of π-π stacked di-, tri-, tetra-, and pentamer aggregates of the fused polycyclic aromatic hydrocarbons (PAHs) naphthalene, anthracene, phenanthrene, tetracene, pyrene, and coronene as well as benzene. These aggregates (stabilized by dispersion interactions) are highly relevant to the intermolecular aggregation of asphaltenes, major components of heavy petroleum. The strength of π-π stacking interaction is evaluated with respect to the π-stacking distance and thermochemistry results, such as aggregation enthalpies, entropies, and Gibbs free energies (ΔG(298)).

DFT studies of imino and thiocarbonyl ligands with the pentaaqua Mg²⁺ cation: affinity and associated parameters.

The affinity of the pentaaqua Mg(2+) cation for a set of para-substituted imino [HN = CHC₆H₄(R)] and thiocarbonyl [S = CHC₆H₄(R)] ligands (R = H, F, Cl, Br, OH, OCH₃, CH₃, CN, NH₂ and NO₂) was analyzed with DFT (B3LYP/6-31+G(d)) and semi-empirical (PM6-DH2) methods. The interaction enthalpy was calculated to quantify the affinity of the Mg(2+) cation for the ligands. Additionally, geometric and electronic parameters were correlated with the intensity of the metal-ligand interaction.

Interaction between alkaline earth cations and oxo ligands: a DFT study of the affinity of Mg2+ for carbonyl ligands.

The affinities of Mg(2+) for various substituted carbonyl ligands were determined at the DFT (B3LYP/6-31+G(d)) and semi-empirical (PM6) levels of theory. Two sets of carbonyl ligands were studied: monosubstituted [aldehydes R-CHO and RPh-CHO] and homodisubstituted [ketones R(2)C=O and (RPh)(2)C=O], where R = NH(2), OCH(3), OH, CH(3), H, F, Cl, Br, CN, or NO(2)). In the (RPh)(2)CO case, the R group was bonded to the para position of a phenyl ring.

Interactions between alkaline earth cations and oxo ligands. DFT study of the affinity of the Mg²+ cation for phosphoryl ligands.

DFT (B3LYP/6-31+G(d)) calculations of Mg(2+) affinities for a set of phosphoryl ligands were performed. Two types of ligands were studied: a set of trivalent [O = P(R)] and a set of pentavalent phosphoryl ligands [O = P(R)(3)] (R = H, F, Cl, Br, OH, OCH(3), CH(3), CN, NH(2) and NO(2)), with R either bound directly to the phosphorus atom or to the para position of a phenyl ring. The affinity of the Mg(2+) cation for the ligands was quantified by means of the enthalpy for the substitution of one water molecule in the [Mg(H(2)O)(6)](2+) complex for a ligand.

Interaction between alkaline earth cations and oxo-ligands. DFT study of the affinity of the Ca2+ cation for carbonyl ligands.

The affinity of the Ca(2+) ion for a set of substituted carbonyl ligands was analyzed with both the DFT (B3LYP/6-31+G(d)) and semi-empirical (PM6) methods. Two types of ligands were studied: a set of monosubstituted [O=CH(R)] and a set of disubstituted ligands [O=C(R)(2)] (R=H, F, Cl, Br, OH, OCH(3), CH(3), CN, NH(2) and NO(2)), with R either directly bound to the carbonyl carbon atom or to the para position of a phenyl ring. The interaction energy was calculated to quantify the affinity of the Ca(2+) cation for the ligands.