Ž . Ž . A recently developed density functional theory DFT ansatz for the calculation of one-electron spin–orbit SO corrections to NMR chemical shifts has been extended to include two-electron SO operators. The performance of different approximations is evaluated in calculations of H and C nuclear shieldings in the hydrogen halides, the halomethanes, and in iodobenzene. Two-electron contributio...

Square planar dialkyl complexes of nickel, palladium and platinum exhibit intriguing difference in their reactivities. Thermolysis pathways of these dialkyls vary depending on the metal, ligands, alkyl groups, geometry as well as the presence or absence of added ligand. Kinetic studies on the thermolysis and trans-cis isomerizations of PdR,L2 (L = tertiary phosphine) complexes showed involvemen...

Our recent work has provided new insights into the equilibria and species that exist in aqueous solution at different pHs for the boric acid - hydrogen peroxide system, and the role of these species in oxidation reactions. Most recently, (M. C. Durrant, D. M. Davies and M. E. Deary, Org. Biomol. Chem., 2011, 9, 7249-7254), we have produced strong theoretical and experimental evidence for the ex...

(1) It is shown that in the hydrogen halide molecules (internuclear distance ro) the proton penetrates the electronic shell of the anion to a depth which for the simplified case of spherical symmetry can be characterized by the condition: The amount of negative charge beyond the sphere of radius ro equals Ie, (2) From the dipole moments p.=xero of the hydrogen halide molecules it can be conclud...

Affinities of alkali cations and halide anions for the peptide group were quantified using molecular dynamics simulations of aqueous solutions of N-methylacetamide using both nonpolarizable and polarizable force fields. Potassium and, more strongly, sodium exhibit an affinity for the carbonyl oxygen of the amide group, while none of the halide anions shows any appreciable attraction for the ami...

Uptake of several atmospheric molecules on free ice nanoparticles was investigated. Typical examples were chosen: water, methane, NO(x) species (NO, NO(2)), hydrogen halides (HCl, HBr), and volatile organic compounds (CH(3)OH, CH(3)CH(2)OH). The cross sections for pickup of these molecules on ice nanoparticles (H(2)O)(N) with the mean size of N≈260 (diameter ~2.3 nm) were measured in a molecula...

Highly correlated ab initio wave functions within the MRCI approach are used in a comparative study of the interactions between C2 and the three hydrogen halides HX (X = F, Cl, Br). Test calculations are also presented using the UCCSD(T)-F12 approach. The asymptotic regions are investigated for different relative orientations of the two moieties. It is shown that the three systems C2 + HX are b...

A many-body theory approach developed by the authors [Phys. Rev. A 70 032720 (2004)] is applied to positron bound states and annihilation rates in atomic systems. Within the formalism, full account of virtual positronium (Ps) formation is made by summing the electron-positron ladder diagram series, thus enabling the theory to include all important many-body correlation effects in the positron p...

CytC3, a member of the recently discovered class of nonheme Fe(II) and alpha-ketoglutarate (alphaKG)-dependent halogenases, catalyzes the double chlorination of L-2-aminobutyric acid (Aba) to produce a known Streptomyces antibiotic, gamma,gamma-dichloroaminobutyrate. Unlike the majority of the Fe(II)-alphaKG-dependent enzymes that catalyze hydroxylation reactions, halogenases catalyze a transfe...