On the electronic structure of 5g

Quasi-relativistic SCF Xα calculations are reported for the hypothetical complexes math, EF6 (E = element 125) and the 5f1 ion NpO22+. The calculations indicate that the E(125) complexes have a 5g1 outer electronic configuration with good agreement with previous predictions. The ligand field energy diagram for g1 system in Oh sysmmetry is discussed in relation to the obtained Xα results

Synthesis, Crystal Structure, Quantum Chemical Calculations, DNA Interactions, and Antimicrobial Activity of [Ag(2-amino-3-methylpyridine)2]NO3 and [Ag(pyridine-2-carboxaldoxime)NO3]

[Ag(2-amino-3-methylpyridine)2]NO3 (1) and [Ag(pyridine-2-carboxaldoxime)NO3] (2) were prepared from corresponding ligands and AgNO3 in water/ethanol solutions, and the products were characterized by IR, elemental analysis, NMR, and TGA. The X-ray crystal structures of the two compounds show that the geometry around the silver(I) ion is bent for complex 1 with nitrate as an anion and trigonal planar for complex 2 with nitrate coordinated. ESI-MS results of solutions of 2 indicate the independent existence in solution of the [Ag(pyridine-2-carboxaldoxime)]+ ion. The geometries of the complexes are well described by DFT calculations using the ZORA relativistic approach. The compounds were tested against 14 different clinically isolated and four ATCC standard bacteria and yeasts and also compared with 17 commonly used antibiotics. Both 1 and 2 exhibited considerable activity against S. lutea, M. lutea, and S. aureus and against the yeast Candida albicans, while 2-amino-3-methylpyridine is slightly active and pyridine-2-carboxaldoxime shows no antimicrobial activity. In addition, the interaction of these metal complexes with DNA was investigated. Both 1 and 2 bind to DNA and reduce its electrophoretic mobility with different patterns of migration, while the ligands themselves induce no change

Synthesis, crystal structure and comparative DFT studies of a 1D Ni(II) polymeric complex of 2-Hydroxypyridine-N-oxide

A novel Nickel (II) complex of 2-hydroxypyridine-N-oxide has been prepared and characterized by X-ray crystal structure analysis, FT-IR, UV spectra and thermogravimetry. The X-ray diffraction study reveals that the nickel complex is a 1D linear polymer in space group Pī with a = 6.250(1), b = 8.746(2), c = 9.462(2) Å, α = 81.76(3)o, β = 79.55(3)o and γ = 81.17(3)o. Two nickel ions are present in the unit cell related by the crystallographic centre of symmetry at ½ ½ ½. There are two different short non-bonded Ni to Ni separations in the polymeric structure: 3.454 and 3.467 Å respectively. Both room temperature magnetic moment measurements, and theoretical calculations are in favor of a simple paramagnetic system. As a complementary study, plane wave pseudopotential DFT calculations were performed, utilizing eight different XC functionals. The PBE and PBE0 functionals reproduce well the X-ray crystal structure of the complex, while the HSE functional gives a band gap which corresponds reasonably to the experimentally estimated value. The results of antimicrobial properties and thermal analysis of the complex are also reported