Despite extensive studies of the amino-functionalized silica surfaces, a comprehensive investigation of the effects of configuration and hydrolysis of 3-aminopropyltriethoxysilan (APTES) molecules attached on silica has not been studied yet. Therefore, the methods of quantum mechanics were used for the study of configuration and hydrolysis forms of APTES molecules attached on the surface. For t...

A theoretical DFT study was employed to investigate the different aspects of electronic structure of the salt of 1,1/(ethane-1,2-diyl)dipyridiniumbisiodate. The interactions between different molecular orbitals were considered by using DFT method. The results from the quantum mechanical calculations were then used to determine the role of donoracceptor interactions on the oxidation strength of ...

Non-covalent interactions are the main forces involved in the recognition, transport and regulation of virtually all events in biological systems [1]. Although the chemical relevance of anionic molecules is very defined, the chemistry of anion receptors is still a growing area [2]. Host molecules which can interact with anionic species through non-covalent interactions have some advantages due ...

BACKGROUND AND PURPOSE Recent studies suggest that normobaric oxygen therapy (NBO) is neuroprotective in acute ischemic stroke. METHODS We performed multivoxel magnetic resonance spectroscopic imaging and diffusion/perfusion MRI in patients with stroke treated with NBO or room air. Imaging was performed before, during, and after therapy. RESULTS Voxel-based analysis showed excellent correla...

The ground state, oxidized ground state, (3)MLCT and (3)MC excited states have been studied by DFT and TDDFT for two Ru(II) complexes bearing an N(6) or N(5)C coordination sphere. The effect of replacing one Ru-N dative bond by one Ru-C covalent bond have been studied and quantified on their ground state by the means of geometry optimization, NBO analysis and calculation of their IR vibrations....

The effect of interactions of various Ia and IIa cations with two positions of the adenine-thymine (A-T) and guanine-cytosine (G-C) base pairs on the geometries and individual hydrogen bond (HB) energies have been investigated by using the atoms in molecules (AIM) method at the B3LYP/6-311++G(d,p) level of theory. The cations that possess higher charge/radius (q/rad) ratio make higher changes o...

Lincosamides are a class of antibiotics used both in clinical and veterinary practice for a wide range of pathogens. This group of drugs inhibits the activity of the bacterial ribosome by binding to the 23S RNA of the large ribosomal subunit and blocking protein synthesis. Currently, three X-ray structures of the ribosome in complex with clindamycin are available in the Protein Data Bank, which...

Density functional theory (DFT) has been used to determine the geometric and electronic structure of series [cis-{(?5-C5H3)2(CMe2)2}-Ru2(CO)4(?-H)n]n+ (n = 0, 1, 2) their di-tert-butyl-bipyridine (bipy) analogs ((CO)2 bipy). The results have analyzed by using natural bond orbitals (NBO) quantum atoms in molecules (QTAIM). This provide a thorough description changes bonding that occur as Ru-Ru n...