IN THIS WORK WE EXPLORE THE ABILITY OF THE C36 FULLERENE TO INTERACT WITH AMINO ACIDS WITH ALIPHATIC RGROUPS AT THE DFT-B3LYP/6-31+G* (D) LEVEL OF THEORY. C36 IS THE MOST IMPORTANT FULLERENE CAGE.THE CALCULATIONS SUGGEST THAT THE MOST FAVORABLE INTERACTIONS OF THE FULLERENE IS INTERACT WITH AMINO ACIDS WITH ALIPHATIC R-GROUPS, WHICH IS RELATED TO THE BACKBONE STRUCTURE OF THE CORRESPONDING AMINO ACIDS. WE PROPOSE CORRELATIONS OF THE DISSOCIATION, ENERGY OF HF, EB, (HOMO)/LUMO BAND GAPS, NBO AND HYDROPHOBICITY AND ENERGY, LENGTH OF THE BONDS, THE BOND ANGLES CONSTANTS IN RELATION TO THE COMPUTED QUANTUM CHEMICAL, THERMOCHEMISTRY BEHAVIOR.

IN THIS STUDY, THE GEMCITABINE ANTICANCER DRUG WAS INVESTIGATED USING THEORY. DFT AND TD-DFT CALCULATIONS AT MPW1PW91 METHOD WITH 6-311++G (2D, 2P) BASE SET HAVE BEEN USED TO INVESTIGATE THE GROUND AND EXCITED STATES BEHAVIORS OF DRUG IN GAS PHASE AND ETHANOL. SOLVENT MOLECULES INFLUENCE ON THE EQUILIBRIUM STRUCTURES SPECIES. THE CALCULATED THERMODYNAMIC PROPERTIES, THE RELATIVE ENERGY, DIPOLE MOMENT, STRUCTURAL PARAMETERS, Highest Occupied Molecular Orbital ((HOMO)) AND THE LOWEST UNOccupied (LUMO) ENERGIES, DOS PLOT AND ENERGY GAP SHOW THAT CHARGE TRANSFER OCCURS WITHIN THE MOLECULE. THE AIM IS TO ACHIEVE A MORE STABLE FORM OF THE DRUG GEMCITABINE IN TWO GAS PHASE AND SOLVENTS. THE CALCULATIONS SHOWED THAT THE STRUCTURE OF THE DRUG IN THE GROUND STATE AND THE EXCITED SOLVENT PHASE IS MORE STABLE THAN THE GAS PHASE. ENERGY GAP IN THE EXCITATION OF GAS AND ETHANOL IS DIFFERENT IN TWO PHASES.

INTRODUCTION: (HOMO) AND LUMO ARE ACRONYMS FOR Highest Occupied Molecular Orbital AND LOWEST UNOccupied Molecular Orbital, RESPECTIVELY. THE ENERGY DIFFERENCE BETWEEN THE (HOMO) AND LUMO IS TERMED THE (HOMO)–LUMO GAP. (HOMO) AND LUMO ARE SOMETIMES REFERRED TO AS FRONTIER OrbitalS [1].FUKUI REALIZED THAT A GOOD APPROXIMATION FOR REACTIVITY COULD BE FOUND BY LOOKING AT THE FRONTIER OrbitalS ((HOMO)/LUMO). THIS WAS BASED ON THREE MAIN OBSERVATIONS OF Molecular Orbital THEORY AS TWO MOLECULES INTERACT: I) THE Occupied OrbitalS OF DIFFERENT MOLECULES REPEL EACH OTHER. II) POSITIVE CHARGES OF ONE MOLECULE ATTRACT THE NEGATIVE CHARGES OF THE OTHER.III) THE Occupied OrbitalS OF ONE MOLECULE AND THE UNOccupied OrbitalS OF THE OTHER (ESPECIALLY THE (HOMO) AND LUMO) INTERACT WITH EACH OTHER CAUSING ATTRACTION. FROM THESE OBSERVATIONS, FRONTIER Molecular Orbital (FMO) THEORY SIMPLIFIES REACTIVITY TO INTERACTIONS BETWEEN THE (HOMO) OF ONE SPECIES AND THE LUMO OF THE OTHER.IN THIS PROJECT, (HOMO)-LUMO GAP FOR GLYCINE RESIDUE CALCULATED USING DENSITY FUNCTIONAL THEORY ALONG WITH B3LYP/6-311G++ (2D, 2P) LEVEL. THE FRONTIER OrbitalS RESULTS WAS USED TO ILLUSTRATE GLYCINE ENTITIES INVOLVED IN THERMODYNAMIC CYCLE CONSTRUCTED FOR DETERMINATION OF PKA VALUE OF GLYCINE.

WE STUDIED THE RELATIVE STABILITYOF THE TWO CATALYSTS,PT(BPYM)CL2 AND PT(BPYM)BR2, IN C‒H BOND ACTIVATION REACTIONS (BPYM IS 2,2-BIPYRIMIDINE). THE RESULTS OF CALCULATIONS OF CATALYSTS INDICATED THAT ACTIVATION ENERGY, THE Highest Occupied Molecular Orbital ((HOMO)) AND THE LOWESTUNOccupied Molecular Orbital (LUMO) ENERGY, ...

IN THIS ARTICLE, WE INVESTIGATE THE TOTAL AND PROJECTED DENSITY OF STATE FOR ADDING FOUR PHENYL RINGS ON DIFFERENT POSITION OF TETRACENE MOLECULE BY USING DENSITY FUNCTIONAL THEORY WITH SIESTA CODE. ALSO, WE FOUND THAT, THE MOST CONTRIBUTION OF ATOMIC STATES IN THE Highest Occupied Molecular Orbital ((HOMO)) AND THE LOWEST UNOccupied Molecular Orbital (LUMO) ARE DUE TO THE P OrbitalS OF CARBON ATOMS. ...

THE THEORETICAL INVESTIGATION RESULTS OF 4- SUBSTITUATED 1,2-DIAZANAPHTALENESS, WERE REPORTED IN THIS PAPER. QUANTUM CHEMICAL CALCULATIONS WERE PERFORMED ON EIGHT MOLECULES AT AB INITIO/HF/6-311G (D, P) LEVEL OF THEORY. CALCULATED OPTIMIZED Molecular STRUCTURE, DIPOLE MOMENT, POLARIZABILITY, AND FIRST HYPERPOLARIZABILITY FOR ALL OF MOLECULES IN THREE CASE (GAS PHASE, IN PRESENCE OF WATER AND ETHANOL) WERE DEDICATED. ALSO, THE FRONTIER Molecular OrbitalS (FMOS), E(HOMO) (THE Highest Occupied Molecular Orbital ENERGY), ELUMO (THE LOWEST UNOccupied Molecular Orbital ENERGY), AND (HOMO)-LUMO ENERGY GAP (ΔE) ARE INVESTIGATED. ...