Benzothiazole (BTH) and its derivatives are organic molecules with biologic actions. Because of their many applications, they are produced on a massive scale and used in a number of environmental compartments. Their d...Benzothiazole (BTH) and its derivatives are organic molecules with biologic actions. Because of their many applications, they are produced on a massive scale and used in a number of environmental compartments. Their discharge into water produces environmental problems, exposing our environment to public health problems. A solution that can contribute to their deterioration is becoming a necessity. For this reason, a conceptual analysis of the reactivity of benzothiazole and four of its compounds was undertaken in order to investigate certain aspects of their biodegradability. A theoretical investigations of the compounds studied were conducted in the gas and water phases with the most widely used density functional theory method, Becke-3-Parameter-Lee-Yang-Parr (B3LYP) with 6-31G+ (d, p) basis. Reactivity study calculated global indices of reactivity revealed that 2-SCH3_BTH is the most reactive. Dipole moment values analysis reveals that 2-NH2_BTH is the most soluble in water, while the lipophilicity shows that 2-NH2_BTH is the most hydrophilic compound. Thermodynamic parameters values reflect that reactions are respectively exothermic and spontaneous. By analyzing an Electrostatic Molecular Potential (EMP) map, researchers can pinpoint reactive sites on a molecule and anticipate its reactivity. This assessment is further enhanced by incorporating global and local reactivity descriptors. Additionally, an exploration of frontier molecular orbitals offers valuable insights into the molecule’s charge transfer characteristics. Moreover, a combined examination of internal and external molecular interactions unveils hyperconjugative interactions arising from charge delocalization, as elucidated through natural bond orbital (NBO) analysis.展开更多
Theoretical calculations were carried out using the DFT/B3LYP/6-31+G(d) methodology in an attempt to predict the preferred interaction site of a polyfunctional heterocyclic base 3-methyl-4- pyrimidone molecule with a ...Theoretical calculations were carried out using the DFT/B3LYP/6-31+G(d) methodology in an attempt to predict the preferred interaction site of a polyfunctional heterocyclic base 3-methyl-4- pyrimidone molecule with a series of proton donors of different acidic strength, i.e. water, methanol, phenol, 1-naphtol, 2,4,5 trichlorophenol, pentachlorophenol, picric acid and hydrogen chlordide. Computed H-bond interaction energies (ΔEc), internuclear and intermolecular distances r(O…H) and r(O…O), infrared frequency shifts Δv(C=O) and (Δv(OH) are proved to be reliable parameters for predicting the preferred interaction site of 3-methyl-4-pyrimidone. These computational data suggest that the O-H…O=C complex is preferred with water, methanol, phenol, 1-naphtol, 2,4,5 trichlorophenol and pentachlorophenol. However, for H-bonding with stronger acids such as picric acid or hydrochloric acid, the computational data suggest that the H-bonding occurs at the N1 ring atom of 3-methyl-4-pyrimidone. In the O-H…O=C com- plex, where the H-bond at the carbonyl O-atom can be oriented “anti” (Ha) and “syn” (Hb) with respect to the N3 atom, the same computational data suggest a higher stability of the “anti-O” compared to the “syn-O” orientation.展开更多
The ammonia adsorption on the GaN (0001) surface has been investigated by using DFT/B3LYP method combined with the cluster model approach. The dissociative adsorp- tion of NH2 and H is found thermodynamically favored ...The ammonia adsorption on the GaN (0001) surface has been investigated by using DFT/B3LYP method combined with the cluster model approach. The dissociative adsorp- tion of NH2 and H is found thermodynamically favored relative to the molecular NH3 adsorption by decreasing the total energy of 0.95 eV. The adsorption geometries of the molecular and dis- sociative NH3 are given in detail, among which the molecular NH3 bonds to the surface Ga with its lone electronic pair, and the N atom of NH2 adspecies forms the four-fold coordinated N by bridging two surface Ga atoms.展开更多
The SCR reaction mechanism of NO with C3H6catalyzed by CuO was studied by the method of Density Functional Theory(DFT)at the B3LYP/LanL2DZ levels.The optimized geometries of the stationary points on the potential surf...The SCR reaction mechanism of NO with C3H6catalyzed by CuO was studied by the method of Density Functional Theory(DFT)at the B3LYP/LanL2DZ levels.The optimized geometries of the stationary points on the potential surface were obtained and the transition state was confirmed by IRC and vibration analysis.The activation energy was calculated being 34.26 kJ/mol.It was shown that propylene reacted firstly with Cu forming intermediate,and then nitrogen monoxide immediately reacted with the intermediate to be reduced.It was proved to be a direct interaction mechanism.展开更多
DFT quantum chemical computations have been carried out at the B3LYP/6-31G (d) level. Full geometry optimization has been performed and equilibrium geometries for a new series of phenyl thiazoles have been located. Gr...DFT quantum chemical computations have been carried out at the B3LYP/6-31G (d) level. Full geometry optimization has been performed and equilibrium geometries for a new series of phenyl thiazoles have been located. Ground state electronic properties, charge density distributions, dipole moments and its components have been calculated and reported. Effect of substituents on the geometry and on the polarization of the studied series of compounds are analyzed and discussed. Some structural features have been pinpointed to underline the affinity and selectivity of the studied compounds as adenosine A3-receptor antagonists. Results of the present work indicate that activity towards A3 receptor sites is directly correlated with both of the polarity and the co-planarity of the thiazole.展开更多
A novel interesting d^（10） metal hybrid, [1,2-C_6H_（10）（NH_3）_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate（II） was grown, structurally characterized and their vibrational as well as thermal and diele...A novel interesting d^（10） metal hybrid, [1,2-C_6H_（10）（NH_3）_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate（II） was grown, structurally characterized and their vibrational as well as thermal and dielectric proprieties were studied. A preliminary single crystal X-ray diffraction structural analysis has revealed that the latter crystallizes in the monoclinic system（space group C2/c）. Its unit cell dimensions are a = 32.394（9） ？, b = 12.217（4） ？, c = 10.175（3） ？, β = 97.852（13）° with Z = 12 and the refinement converged to R = 0.034 and ωR = 0.065. Hirshfeld surface analyses, especially d_（norm）surface and fingerprint plots were used for decoding intermolecular interactions in the crystal network. The optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the present compound were theoretically examined by the DFT/B3 LYP method with the Lan L2 DZ basis set. The thermal and dielectric analyses suggested the presence of ferroelectric phase transition at 314 K.展开更多
The a-amino acid derivatives constitute a class of compounds of particular medicinal and synthetic attention and considerable interest has been devoted to their synthesis in recent years.In the present work,we develop...The a-amino acid derivatives constitute a class of compounds of particular medicinal and synthetic attention and considerable interest has been devoted to their synthesis in recent years.In the present work,we develop the computational study of the synthesis reaction of new pyrazolyl a-amino esters derivatives using the Gaussian 09based on the DET/B3LYP density functional theorv method,with the base 6-31G(d.p)to ensure the possibility of carrying out these reactions within the laboratory of synthesis.Indeed,this research has encouraged us to establish an economical synthesis strategy of these products in overall vields of 73.5%to 87%to have access to new active biomolecule through the O-alkvlation reaction between methyl a-azidoglycinate N-benzoylated and primary pyrazole alcohols(3,5-dimethyl-1 H-pyrazol-1-yl)methanol,(1H-pyrazol-1-yl)methanol and(3-ethoxy-5-methyl-1H-pyrazol-1yl)methanoll under different operating conditions.The structure of the prepared heterocyclic systems was characterized by conventional spectroscopic techniques,like H NMR.I3℃NMR,and MS.The results revealed that the experimental study is in good correlation with the computational one.展开更多
文摘Benzothiazole (BTH) and its derivatives are organic molecules with biologic actions. Because of their many applications, they are produced on a massive scale and used in a number of environmental compartments. Their discharge into water produces environmental problems, exposing our environment to public health problems. A solution that can contribute to their deterioration is becoming a necessity. For this reason, a conceptual analysis of the reactivity of benzothiazole and four of its compounds was undertaken in order to investigate certain aspects of their biodegradability. A theoretical investigations of the compounds studied were conducted in the gas and water phases with the most widely used density functional theory method, Becke-3-Parameter-Lee-Yang-Parr (B3LYP) with 6-31G+ (d, p) basis. Reactivity study calculated global indices of reactivity revealed that 2-SCH3_BTH is the most reactive. Dipole moment values analysis reveals that 2-NH2_BTH is the most soluble in water, while the lipophilicity shows that 2-NH2_BTH is the most hydrophilic compound. Thermodynamic parameters values reflect that reactions are respectively exothermic and spontaneous. By analyzing an Electrostatic Molecular Potential (EMP) map, researchers can pinpoint reactive sites on a molecule and anticipate its reactivity. This assessment is further enhanced by incorporating global and local reactivity descriptors. Additionally, an exploration of frontier molecular orbitals offers valuable insights into the molecule’s charge transfer characteristics. Moreover, a combined examination of internal and external molecular interactions unveils hyperconjugative interactions arising from charge delocalization, as elucidated through natural bond orbital (NBO) analysis.
文摘Theoretical calculations were carried out using the DFT/B3LYP/6-31+G(d) methodology in an attempt to predict the preferred interaction site of a polyfunctional heterocyclic base 3-methyl-4- pyrimidone molecule with a series of proton donors of different acidic strength, i.e. water, methanol, phenol, 1-naphtol, 2,4,5 trichlorophenol, pentachlorophenol, picric acid and hydrogen chlordide. Computed H-bond interaction energies (ΔEc), internuclear and intermolecular distances r(O…H) and r(O…O), infrared frequency shifts Δv(C=O) and (Δv(OH) are proved to be reliable parameters for predicting the preferred interaction site of 3-methyl-4-pyrimidone. These computational data suggest that the O-H…O=C complex is preferred with water, methanol, phenol, 1-naphtol, 2,4,5 trichlorophenol and pentachlorophenol. However, for H-bonding with stronger acids such as picric acid or hydrochloric acid, the computational data suggest that the H-bonding occurs at the N1 ring atom of 3-methyl-4-pyrimidone. In the O-H…O=C com- plex, where the H-bond at the carbonyl O-atom can be oriented “anti” (Ha) and “syn” (Hb) with respect to the N3 atom, the same computational data suggest a higher stability of the “anti-O” compared to the “syn-O” orientation.
基金Supported by the National Natural Science Foundation of China (202730313)
文摘The ammonia adsorption on the GaN (0001) surface has been investigated by using DFT/B3LYP method combined with the cluster model approach. The dissociative adsorp- tion of NH2 and H is found thermodynamically favored relative to the molecular NH3 adsorption by decreasing the total energy of 0.95 eV. The adsorption geometries of the molecular and dis- sociative NH3 are given in detail, among which the molecular NH3 bonds to the surface Ga with its lone electronic pair, and the N atom of NH2 adspecies forms the four-fold coordinated N by bridging two surface Ga atoms.
基金Sponsored by the Education Department of Heilongjiang Province(Grant No.11511117).
文摘The SCR reaction mechanism of NO with C3H6catalyzed by CuO was studied by the method of Density Functional Theory(DFT)at the B3LYP/LanL2DZ levels.The optimized geometries of the stationary points on the potential surface were obtained and the transition state was confirmed by IRC and vibration analysis.The activation energy was calculated being 34.26 kJ/mol.It was shown that propylene reacted firstly with Cu forming intermediate,and then nitrogen monoxide immediately reacted with the intermediate to be reduced.It was proved to be a direct interaction mechanism.
文摘DFT quantum chemical computations have been carried out at the B3LYP/6-31G (d) level. Full geometry optimization has been performed and equilibrium geometries for a new series of phenyl thiazoles have been located. Ground state electronic properties, charge density distributions, dipole moments and its components have been calculated and reported. Effect of substituents on the geometry and on the polarization of the studied series of compounds are analyzed and discussed. Some structural features have been pinpointed to underline the affinity and selectivity of the studied compounds as adenosine A3-receptor antagonists. Results of the present work indicate that activity towards A3 receptor sites is directly correlated with both of the polarity and the co-planarity of the thiazole.
文摘A novel interesting d^（10） metal hybrid, [1,2-C_6H_（10）（NH_3）_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate（II） was grown, structurally characterized and their vibrational as well as thermal and dielectric proprieties were studied. A preliminary single crystal X-ray diffraction structural analysis has revealed that the latter crystallizes in the monoclinic system（space group C2/c）. Its unit cell dimensions are a = 32.394（9） ？, b = 12.217（4） ？, c = 10.175（3） ？, β = 97.852（13）° with Z = 12 and the refinement converged to R = 0.034 and ωR = 0.065. Hirshfeld surface analyses, especially d_（norm）surface and fingerprint plots were used for decoding intermolecular interactions in the crystal network. The optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the present compound were theoretically examined by the DFT/B3 LYP method with the Lan L2 DZ basis set. The thermal and dielectric analyses suggested the presence of ferroelectric phase transition at 314 K.
基金Supported by the Centre National de la Recherche Scientifique et Techniques,Rabat,Morocco(No.PROTARS D13/03).
文摘The a-amino acid derivatives constitute a class of compounds of particular medicinal and synthetic attention and considerable interest has been devoted to their synthesis in recent years.In the present work,we develop the computational study of the synthesis reaction of new pyrazolyl a-amino esters derivatives using the Gaussian 09based on the DET/B3LYP density functional theorv method,with the base 6-31G(d.p)to ensure the possibility of carrying out these reactions within the laboratory of synthesis.Indeed,this research has encouraged us to establish an economical synthesis strategy of these products in overall vields of 73.5%to 87%to have access to new active biomolecule through the O-alkvlation reaction between methyl a-azidoglycinate N-benzoylated and primary pyrazole alcohols(3,5-dimethyl-1 H-pyrazol-1-yl)methanol,(1H-pyrazol-1-yl)methanol and(3-ethoxy-5-methyl-1H-pyrazol-1yl)methanoll under different operating conditions.The structure of the prepared heterocyclic systems was characterized by conventional spectroscopic techniques,like H NMR.I3℃NMR,and MS.The results revealed that the experimental study is in good correlation with the computational one.
