the physical and chemical properties of pyrazole and pyrazoline molecules were theoreticallystudied by gaussian 03, software with nmr and molecular orbital calculations at b3lyp/6-31g andb3lyp/6-31+g(d) levels, in gas phase and solution. in this study a comparison effect of threesolvents with different dielectric constants on pyrazole and pyrazoline molecules in aspect energyinteraction between...

In this study, environmental stains were removed from maxillofacial elastomers by solvent extraction. Silastic 44210, an RTV silicone with proven color and physical property stability, was stained with lipstick, disclosing solution, and methylene blue. These stains were then removed by solvent extraction with each of four chemically dissimilar solvents, namely: toluene, benzene, 1,1,1-trichloro...

A series of A₃B and A₄ type mesoporphyrinic complexes were synthesized with superior yields using microwave irradiation under solvent-free conditions. The structures of the complexes were confirmed using elemental analysis, FT-IR, UV-Vis, EPR and NMR spectral data. The influence of environmental polarity on spectral properties of the mesoporphyrinic complexes was investigated. The obtained resu...

in this study, confined impinging liquid jets are used to produce nanoparticles of carbamazepine (cbz). the effect of operating parameters, such as the kind of solvent,cbz concentration, flow rate of solution and antisolvent on particle size, are experimentally investigated. the scanning electron micrograph (sem) photomicrographs show that nanodrug with smaller particle is achievable by using s...

Solvent relaxation (SR) refers to the dynamic process of solvent reorganisation in response to an abrupt change in charge distribution of a dye via electronic excitation. The temporal response can be monitored through the observation of the dynamic StokesΔ shift ν(t) of the dyeΔs emission maximum frequency. The complete time-dependent StokesΔ shift " ν (" ν = ν(0)-ν(∞)) increases with increasin...

Controlled mirror symmetry breaking arising from chemical and physical origin is currently one of the hottest issues in the field of supramolecular chirality. The dynamic twisting abilities of solvent molecules are often ignored and unknown, although the targeted molecules and polymers in a fluid solution are surrounded by solvent molecules. We should pay more attention to the facts that mostly...

The essential features of the in vitro refolding of myoglobin are expressed in a solvable physical model. Alpha helices are taken as the fundamental collective coordinates of the system, while the refolding is assumed to be mainly driven by solvent-induced hydrophobic forces. A quantitative model of these forces is developed and compared with experimental and theoretical results. The model is t...

Poly(aryl ether amide) containing o-nitroanilide forms a physical gel in polar aprotic solvents by solvent-induced change of hydrogen bonding modes, in which hydrogen bonding acceptor solvent molecules break intramolecular hydrogen bonding of o-nitroanilide and induce intermolecular hydrogen bonding.