In this article, theoretical studies on the selective complexation of the halide ions (F¯, Cl¯ and Br¯) and ion pairs (Na+F¯, Na+Cl¯ and Na+Br¯) with the cyclic nano-hexapeptide (CP) composed of L-proline have been performed in the gas phase. In order to calculate the dispersion interaction energies of the CP and ions, DFT-D3 calculations at the M05-2X-D3/6-31G(d) level was employed. Based on t...

The observation that some properties attributed to atoms and functional groups are transferable from one molecule to another has played a key role in the development of chemistry. This observation provides a basis for group additivity schemes and is exemplified by the constancy of group contributions to thermodynamic and spectroscopic properties. But what is the electronic basis of this empiric...

Tetrel bond is analysed for a series of ZF4 (Z = C, Si, Ge) complexes with one and two NH3 or AsH3 ligands. The MP2/aug-cc-pVTZ calculations were performed and supported by results of the Quantum Theory of “Atoms in Molecules” (QTAIM) and the Natural Bond Orbitals (NBO) approaches. The Z-tetrel atoms of complexes analysed interact through their σ-holes with nitrogen or arsenic Lewis base centre...

A theoretical study was performed to evaluate the defersirox potency to chelate aluminum (Al) and gallium (Ga) as the toxic metals in biological systems. Deferasirox as an important class of chelators, which binds to the metallic center with the ratio of 1:2, is used to remove the toxic metals in the case of iron overload disease. The effects of water and DMSO as the solvent on the electronic n...

The B3LYP/6-31++G** density functional calculations were used to obtain minimum geometries and interaction energies between the molecular hydrogen and nanostructures of fullerenes, C20 (cage), C20 (bowl), C19Si (bowl, penta), C19Si (bowl, hexa). The H2 molecule is set as adsorbed in the distance of 3Å at vertical position from surface above the pentagonal and hexagonal sites of nanostructures. ...

The log K(1) value of analytical quality was obtained for the NiNTPA complex using the density functional theory (DFT)-computed (at the B3LYP/6-311++G(d,p) level of theory in solvent, CPCM/UAKS) G(aq) values of the lowest-energy conformers of the ligands, nitrilotriacetic acid (NTA) and nitrilotri-3-propanoic acid (NTPA), and the Ni(II) complexes (NiNTA and NiNTPA). The described mathematical p...

Herein, a theoretical study on the stability of some vic-dioxime complexes of Ni(II), Pd(II) and Pt(II) in gas and aqueous phases is reported. The DFT/M06/SDD and DFT/M06/6-31G+(d,p) levels of theory were adopted for the metal ions and for every other element respectively. Structural analyses of investigated complexes have revealed square planar geometries stabilized by two O–H⋯Cl hydrogen bond...

A new approach for computing the atom-in-molecule [quantum theory of atoms in molecule (QTAIM)] energies in Kohn-Sham density-functional theory is presented and tested by computing QTAIM energies for a set of representative molecules. In the new approach, the contribution for the correlation-kinetic energy (T(c)) is computed using the density-functional theory virial relation. Based on our calc...

The conformational isomerism and stereoelectronic interactions present in 2'-haloflavonols were computationally analyzed. On the basis of the quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis, the conformer stabilities of 2'-haloflavonols were found to be dictated mainly by a C=O···H-O intramolecular hydrogen bond, but an unusual C-F···H-O hydrogen-bond and in...

Six new multicomponent solids of 9-ethyladenine and oxalic acid have been detected characterized. The salt screening has performed by mechanochemical solvent crystallization processes. Single crystals the anhydrous salts in 1:1 2:1 nucleobase:coformer molar ratio were obtained solution elucidated single-crystal X-ray analysis. supramolecular interactions observed these studied using density fun...