Ab initio computation is performed on the binuclear sandwich complexes, M2(?5-Sb5)2. Eclipsed and staggered conformations are generated due to ?5 mode of binding by Sb5- ligand with alkaline earth metals (Be Mg metals). The complexes thermodynamically stable at room temperature. electron density descriptors natural bond orbital (NBO) analysis confirmed covalent nature M-M bond. Both Be2(?5-Sb5)...

When PH(3) is paired with NH(3), the two molecules are oriented such that the P and N atoms face one another directly, without the intermediacy of a H atom. Quantum calculations indicate that this attraction is due in part to the transfer of electron density from the lone pair of the N atom to the σ(∗) antibond of a P-H covalent bond. Unlike a H-bond, the pertinent hydrogen is oriented about 18...

A variety of density matrix based methods for the analysis and visualization of electronic excitations are discussed and their implementation within the framework of the algebraic diagrammatic construction of the polarization propagator is reported. Their mathematical expressions are given and an extensive phenomenological discussion is provided to aid the interpretation of the results. Startin...

The density functional theory (DFT) calculations at the level of B3LYP/6-31G was carried out on the structure 4(5)-Imidazole-carbaldehyde-N(5)-phenylthiosemicarbazone (ImTPh) in gas phase using Gaussian 03. Dipole moment (Debye), energy of structure formation (HF; kcal/mol) and point group, NMR parameters such as isotropic shielding (σiso) and anisotropic shielding (σaniso), σ11, σ22 and σ33 ob...

Heterobimetallic complexes containing short uranium-group 10 metal bonds have been prepared from monometallic IU(IV)(OAr(P)-κ(2)O,P)3 (2) {[Ar(P)O](-) = 2-tert-butyl-4-methyl-6-(diphenylphosphino)phenolate}. The U-M bond in IU(IV)(μ-OAr(P)-1κ(1)O,2κ(1)P)3M(0), M = Ni (3-Ni), Pd (3-Pd), and Pt (3-Pt), has been investigated by experimental and DFT computational methods. Comparisons of 3-Ni with t...

Density functional theory is used to study the mechanism of the title reaction, one of the first catalytic asymmetric 6π-electrocyclizations observed experimentally. The benzylideneacetone-derived phenyl hydrazone is chosen as model substrate for the cyclization reaction, both in the protonated (A) and unprotonated (B) form, while the isoelectronic carbon analogue, 1,5-diphenylpentadienyl anion...

We have carried out a theoretical investigation of the methylalkalimetal monomers CH3M and tetramers (CH3M)4 with M = Li, Na, K, and Rb and, for comparison, the methyl halides CH3X with X = F, Cl, Br, and I, using density functional theory (DFT) at BP86/TZ2P. Our purpose is to determine how the structure and thermochemistry (e.g., C-M bond lengths and strengths, oligomerization energies) of org...

Density function M06 method has been used to optimize the geometries of shikonin -thymine at 6-311++G** basis. Finally, fourteen stabilized complexes have been obtained. Theories of atoms in molecules (AIM) and natural bond orbital (NBO) have been utilized to investigate the hydrogen bonds involved in all the systems. The interaction energies of all the complexes were corrected by basis set sup...

We report the synthesis of penicillamine-protected Ag20 nanoclusters (NCs), with properties of high monodispersity, red fluorescence and water solubility. Full characterization of the Ag20 NCs is addressed, along with first-principles optimization calculations, revealing the chemical composition and structure of the as-prepared Ag NCs within a molecular formula [Ag20(DPA)18-H]-. Moreover, natur...

The chiral self-discrimination of twelve molecules showing axial chirality has been studied. They included peroxides, hydrazines, carboxylic acids, amides, and allenes. The homo and heterochiral dimers of the selected compounds, that present two hydrogen bonds, have been studied by means of density functional theory ~B3LYP/6-311G**! and ab initio ~MP2/6-311G** and MP2/6-31111G**! methods. The e...