ab initio and dft methods have been used to study the seven tautomeric forms of 5-methylcytosine molecule.the related tautomer in gas phase have been studied at hf/6-31g, hf/6-31g* and b3lyp/6-31g* levels oftheory. the structures,enthalpies,entropies,gibbs free energies,relative tautomerization energies of tautomersand tautomeric equilibrium constants were compared and analyzed along with full ...

Elastic matrix distortion around a growing inclusion of a new phase is analyzed and the associated contribution to the Gibbs free energy is considered. The constant-composition transformation from the parent to product phase is considered within the frame of Landau theory of phase transitions. The volume misfit between the inclusion and matrix is assumed to originate from the transformation vol...

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...

In this work, we have studied the solvent effects on values of Gibbs free energy, enthalpy. entropy and dipolemoment in spread of solvents around anticancer thug of temreolomide that is an alighting agent. For thispurpose, the quantum mechanic calculations bawd on Hanrertnick theory at the STO-36/3-2Ith levels havebeen done. Moreover, we have compared resulted thermodynamic values in gas phase ...

The equilibrium chemical reactions taken place in a converter reactor of the Khorasan Petrochemical Ammonia plant was studied using the minimization of Gibbs free energy method. In the minimization of the Gibbs free energy function the Davidon– Fletcher–Powell (DFP) optimization procedure using the penalty terms in the well-defined objective function was used. It should be noted that in the DFP...

Chemical composition of interfaces—free surfaces and grain boundaries—is generally described by the Langmuir–McLean segregation isotherm controlled by Gibbs energy of segregation. Various components of the Gibbs energy of segregation, the standard and the excess ones as well as other thermodynamic state functions—enthalpy, entropy and volume—of interfacial segregation are derived and their phys...

emissions from fossil fuel combustion pose a serious threat to public health and =pose the need for animproved monitoring of polycyclic aromatic hydrocarbons (pars), a major class of persistent organicpollutants. for this purpose the present study reports an investigation of the electronic structure of pyrene byuse of different chemical models we also made a comparison between different chemica...

a study was made on the interaction between histon h1 and sodium n-dodecyl sulphate (sds) in the presence of sodium arsenate inside a phosphate buffer of ph 6.4, using spectroscopy and equilibrium dialysis at 27 °c. the binding data has been used to obtain the gibbs free energy in terms of a theoretical model based on the wyman binding potential. the binding data hs been analysed in terms of hi...