The absorption and fluorescence spectra of 7-dimethylamino cyclopenta [c] coumarin (C138) and 4-methyl-piperidino [g] coumarin (C339) dyes were measured in neutral, aprotic and protic solvents. Solvatochromic shifts of absorption and fluorescence as a function of different solvent polarity parameters (bulk as well as microscopic) were analyzed for these dyes and the ground state dipole moment (...

phospholipids are important for the biological lipid and are commonly used in biophysical studies.A quantumcalculation for two phospholipids Dipalmitoylphosphatidylethanolamine and dipalmitoylphosphatidic acidwere performed using the abinitio software. Geometry optimization structures were obtained at RHF level using3-21G, 6-31G*. These basis sets were used To understanding the effects of envir...

Thermal rearrangement of 7,7-dichloro-[a,c]-dibenzo-[4,1,0]-bicycloheptane (1) to 5,6-dichloro-5Hdibenzo-[a,c]-cycloheptene (2) was studied in the solid phase and in solvents with different polarities. Thefirst-order constants at various temperatures for the rearrangement process were evaluated from theabsorption time data. The activation parameters for this rearrangement were obtained from the...

An effective fragment model is developed to treat solvent effects on chemical properties andreactions. The solvent, which might consist of discrete water molecules, protein, or othermaterial, is treated explicitly using a model potential that incorporates electrostatics,polarization, and exchange repulsion effects. The solute, which one can most generally envision as including some number of so...

The advantages of performing Langevin Dynamics in extended systems are discussed. A simple Langevin Dynamics scheme for producing the canonical ensemble is reviewed, and is then extended to the Hoover ensemble. We show that the resulting equations of motion generate the isobaricisothermal ensemble. The Parrinello-Rahman ensemble is then discussed and we show that despite the presence of intrins...

phospholipids are important for the biological lipid and are commonly used in biophysical studies.a quantumcalculation for two phospholipids dipalmitoylphosphatidylethanolamine and dipalmitoylphosphatidic acidwere performed using the abinitio software. geometry optimization structures were obtained at rhf level using3-21g, 6-31g*. these basis sets were used to understanding the effects of envir...