The influence of cation-π interactions on the strength and nature of intramolecular O...H hydrogen bond has been investigated by quantum chemical calculations in orthohydroxy benzaldehyde (HBA) compound. Ab initio calculations have been performed at MP2/6-311++G** level of theory. Vibrational frequencies and physical properties such as chemical potential and chemical hardness of these compounds...

In the title compound, [Co(C57H52N6O6)], the central CoII atom is coordinated by four pyrrole N atoms of the porphyrin core and one O atom of the crown ether. The complex has a distorted porphyrin core, with mean absolute core-atom displacements of 0.14 (10) (Ca), 0.20 (10) (Cb), 0.24 (4) (Cm) and 0.18 (10) Å (Cav), respectively. The axial Co-O bond length is 2.3380 (15) and the average Co-Np b...

A model for soliton dynamics on a hydrogen-bond network in helical proteins is proposed. It employs in three dimensions the formalism of fully integrable Toda lattices which admits phonons as well as solitons along the hydrogen-bonds of the helices. A simulation of the three dimensional Toda lattice system shows that the solitons are spontaneously created and are stable and moving along the hel...

The structures of 17β-estradiol (estradiol) and its 1:1 cluster with water have been investigated in supersonic jets. The S(1)-S(0) electronic spectrum of estradiol monomer shows four strong sharp bands in the 35050-35200 cm(-1) region. Ultraviolet-ultraviolet hole-burning (UV-UV HB) and infrared-ultraviolet double-resonance (IR-UV DR) spectra of these bands indicate that they are due to four d...

Flash-induced Fourier transform infrared (FTIR) difference spectroscopy has been used to study the water-oxidizing reactions in the oxygen-evolving centre of photosystem II. Reactions of water molecules were directly monitored by detecting the OH stretching bands of weakly H-bonded OH of water in the 3700-3500 cm(-1) region in FTIR difference spectra during S-state cycling. In the S1-->S2 trans...

The vibrational dynamics of vacuum-isolated hydrogen-bonded complexes between water and the two simplest alcohols is characterized at low temperatures by Raman and FTIR spectroscopy. Conformational preferences during adaptive aggregation, relative donor/acceptor strengths, weak secondary hydrogen bonding, tunneling processes in acceptor lone pair switching, and thermodynamic anomalies are eluci...

Introduction and Aim: The enzyme beta-galactosidase is extremely important in the food pharmaceutical industries. goal of this work was to improve lactose hydrolysis process employing convert glucose galactose for alleviating intolerance. Methods: Intracellular extracted from Lactiplantibacillus spp. (GV54 GV66) by cell permeabilized method using toluene/acetone solvents. Lactose performed 50 g...

A sugar-containing polymer was grown on gold surface by surface-initiated atom-transfer radical polymerization (SI-ATRP) of methacrylate monomer, 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranoside (MAIpGIc), using 1,4,8,11-tetraaza-1,4,8,11-tetramethylcyclotetradecane (Me(4)Cyclam) as ligand, 2-bromopropionyl moiety attached on the gold surface as initiator, and Copper(I) brom...

The potential function of Lippincott and Schroeder for linear hydrogen bond has been re-examined and extended to nonlinear hydrogen bond. The parameters originally introduced to the potential function by Lippincott and Schroeder have been determined from the structural parameters such as 0.. .Odistance 0-H bond distance, H.. .O distance and HOO angle. Thevalidity of harmonic oscillator appr...

In the title compound, C15H14O4, the dihedral angle between the benzene rings is 67.18 (8)°. The Ca-Cm-O-Ca (a = aromatic and m = methyl-ene) torsion angle is 172.6 (3)° and an intra-molecular O-H⋯O hydrogen bond generates an S(6) ring. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds into zigzag chains propagating in [001] and C-H⋯π inter-actions also occur.