Intramolecular hydrogen bonds (IHBs) play a central role in the molecular structure, chemical reactivity and interactions of biologically active molecules. Here, we study the IHBs of seven related o-carbonyl hydroquinones and one structurally-related aromatic lactone, some of which have shown anticancer and antioxidant activity. Experimental NMR data were correlated with theoretical calculation...

The neuroprotective effect of oxygen after acute stroke in rats has been shown previously. However, the question of optimal dosing still remains unanswered. Thus, we investigated the use of oxygen at different concentrations by either normobaric oxygenation (NBO) or hyperbaric oxygenation (HBO) at different pressures in a model of transient ischemia/reperfusion in rats. Animals underwent 90 min...

The molecular framework [Fe(NCS)(2)(tmbpz)(2)](tmbpz = 3,3',5,5'-tetramethyl-4,4'-bipyrazolyl) consists of a robust doubly interpenetrated NbO-type network that remains stable on the removal of solvent guest molecules.

The 6-311G(d,p) and SDD basis sets have been used to calculate the vibration frequencies, DFT/B3LYP approach was optimize structure. energy gap of molecule has calculated using lowest unoccupied molecular orbital (LUMO) with highest occupied (HOMO). stability charge delocalization Title investigated natural bond (NBO) analysis. dipole moment, polarizability, first-order hyperpolarizability, as ...

Using data obtained with the Rossi X-ray Timing Explorer, we report the detection of a 5 Hz quasi-periodic oscillation (QPO) in the bright low-mass X-ray binary and Z source Cygnus X-2 during high overall intensities (the high intensity state). This QPO was detected on the so-called normal branch and can be identified with the normal branch QPO or NBO. Our detection of the NBO is the first one ...

DFT-GGA method of Perdew-Burke-Ernzerhof (PBE) is used with aug-cc-PVTZ, 6-311++G**, and Def2-TZVP large basis sets to study the hydrogen bond interactions between oxygen lone pair as a donor electron with hydrogen atom connected to the aniline’s nitrogen as an electron acceptor (H2O···HNH-Ph), and nitrogen lone pair with hydrogen of water molecule (Ph-H2N···HOH...

A theoretical study on the multi-channel hydrogen addition of maleimide containing 2-hydroxy-benzophenone onto polyethylene in ultra-violet (UV) radiation cross-linking process was carried out using density functional theory (DFT) method at B3LYP/6–311 + G(d,p) level. The energetic information and minimum energy path (MEP) are calculated for nine reaction channels. electrophilic reactions two p...

in this research, we report the results of dft calculations using xc-hybrid functional, b3lyp and employ nbo interpretation to investigate the stereoelectronic effects. electrostatic and steric impacts on the conformational properties of 1,2-difluorodiazene (1), 1,2-dichlorodiazene (2) and 1,2-dibromodiazene (3) are also studied. factors determining the thermodynamically stable molecular struct...

The development of sensors that can detect hazardous analytes selectively and accurately, particularly sulfur based irritants, is quite essential. infinite-conjugation in cyclic conducting polymers make them highly sensitive to toxic analytes. We implemented B3LYP-D3/6–311 + G (d, p) level explore the sensing mechanism tetrapyrrole (CTPy) for reliable detection carbonyl sulfide, carbon disulfid...

The quantum theory of atoms-in-molecules (QTAIM) in conjunction with the DFT/B3LYP/6-311++G(2d,2p) wave function are used to compute the atomic, bonded and non-bonded interactions, distributions of the charge density, ρ(r), and its Laplacian, ∇ρ(r), for the ground equilibrium structure of cytosine. The study has been further extended to include two conical intersection (CI) structures that unde...