Molecular dynamics simulations of diluted (≈ 2.5 weight percent) aqueous solutions of two polyelectrolytes, namely sodium carboxy methyl cellulose (CMC) and sodium poly(acrylate) (PAA) have been performed. Water and counterions were taken into account explicitly. For CMC the substitution pattern and starting conformation is all-important. Two simulations of CMC oligomers resulted in different s...

The effect of pressure on the crystal structure of salicylaldoxime has been investigated. The ambient-pressure phase (salicylaldoxime-I) consists of pairs of molecules interacting through oximic OH...O hydrogen bonds; taken with phenolic OH...N intramolecular hydrogen bonds, these dimers form a pseudo-macrocycle bounded by an R4 4(10) motif. The dimers interact principally via pi...pi stacking ...

the character of the intermolecular interactions in cl2-hx (x =f, cl and br) complexes has been investigated by means of the second-order möller–plesset perturbation theory (mp2) and the density functional theory (dft) calculations. the results show that there are two types of lowest interaction potential equilibrium structures in the interactions between cl2 and hx: x∙∙∙cl type geometry and hy...

The OH stretching vibrational spectrum of water was measured in a wide range of temperatures across the triple point, 269 K OH, were determined for the first time within the framework of a harmonic description of the proton dynamics. We found that in the liquid ...

1-Allyl- (2) and 7-allyl-6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one (3) were obtained via the 18-crown-6-ether catalyzed room temperature reaction of 6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H)-one (1) with potassium carbonate and allyl bromide in dry acetone. The structures of these two derivatives were verified by 2D-NMR measurements, including gHSQC and gHM...

The solid-state structures of a series of seven substituted 3-methylidene-1H-indol-2(3H)-one derivatives have been determined by single-crystal X-ray diffraction and are compared in detail. Six of the structures {(3Z)-3-(1H-pyrrol-2-ylmethylidene)-1H-indol-2(3H)-one, C(13)H(10)N(2)O, (2a); (3Z)-3-(2-thienylmethylidene)-1H-indol-2(3H)-one, C(13)H(9)NOS, (2b); (3E)-3-(2-furylmethylidene)-1H-indol...

enaminones are those structures made up three various functional groups including carbonyl, alkeneand amine groups which arelocated along with each other in a conjugate fashion. these compoundsare of much attention due to special characteristics and numerous applications. in the paper, sixvarious enaminone structures were theoretically optimized and after concluding, were compared withequivalen...

Lutein is the one of the main xanthopyll pigments found in the membranes of the macula lutea of the primate vision apparatus. The two functions of lutein have been studied experimentally: protection against oxidative damage of the lipid matrix [1] and screening against excess radiation [2]. This latter function depends on the molecular organisation, i.e. orientation and aggregation of lutein. T...

Ciprofloxacin, an antibacterial agent, is having low solubility in aqueous solution and high rate of absorption from the stomach. It is precipitated at alkaline pH leading to erratic absorption of the drug from small intestine. To overcome these difficulties, controlled release mucoadhesive suspensions have been designed so that safe and effective blood level of Ciprofloxacin can be maintained ...