The complexation of BDHTD （4-benzylidenamino-4,5-dihydro-lH-l,2,4-triazol-5-one derivatives） by divalent doubly charged metal ions M2＋ （M = Mg, Ca, Fe and Cu） has been investigated using the density functional me...The complexation of BDHTD （4-benzylidenamino-4,5-dihydro-lH-l,2,4-triazol-5-one derivatives） by divalent doubly charged metal ions M2＋ （M = Mg, Ca, Fe and Cu） has been investigated using the density functional method B3LYP. Two distinct coordination modes （k2-O,O and k2-O,N） have been taken into account. Geometry optimizations have been performed in gas-phase and solution-phase： acetonitrile and DMF （N,N-dimethylformamide） with the basis set 6-31G（d,p）. The B3LYP method was also used to calculate the stability and free energies of the 24 complexes of BDHTD with metal ions M2＋ （M = Mg, Ca, Fe and Cu） respectively in gas-phase and solution-phase： acetonitrile and DMF. Results indicate that k2-O,N structures are most stable in gas-phase. The influence of substitution on the stability is sensitive in solution-phase. The interaction energies of complexation process in various media have been calculated at B3LYP/6-31G（d,p） and CCSD（T） level. The MIA （metal ion affinity） of BDHTD with M2＋ （M = Mg, Ca, Fe and Cu） in various media has been explored. The results show that the M1A highly varies with the coordination mode and substitution effect. From the calculated Gibb energies of complexation in various media, it is revealed that the complexation is possible in gas in acetonitrile. The ligand＇s affinity toward individual cation M2＋ （M = Mg, Ca, Fe and Cu） has been analysed. A significant reduce of BDEs observed confirms the decrease of the antioxidant activity by the metal chelation. The charge transfer induced by metal chelation is examined using the NBO analysis.展开更多
In this article, we have performed B3LYP/6-31＋G（d） calculations of geometrical and reaction enthalpies of antioxidant mechanisms for ADPHT 1-4 （3-alkyl-4-phenylacetylamino-lH-1,2,4-triazol-5-ones） and its derivat...In this article, we have performed B3LYP/6-31＋G（d） calculations of geometrical and reaction enthalpies of antioxidant mechanisms for ADPHT 1-4 （3-alkyl-4-phenylacetylamino-lH-1,2,4-triazol-5-ones） and its derivatives： HAT （hydrogen atom transfer）, SET-PT （single electron transfer-proton transfer） and SPLET （sequential proton-loss electron transfer） were investigated in gas and solution-phases. Solvent contribution to enthalpies was computed employing integral equation formalism IEF-PCM （integral equation formalism method） method. It turned out that the lowest BDEs （bond dissociation energies） is obtained for C-H bonds due to captodative effect in various media. Results indicate that HAT mechanism represents the most anticipated process in gas-phase from thermodynamic point of view. But, the SPLET represents the thermodynamically preferred reaction pathway in solvents （2-propanol, acetonitrile, DMF （N,N-dimethylformamide） and water）. The authors showed that bond dissociation energies, IP （ionization potential） and PA （proton affinity） are sufficient to evaluate the thermodynamically preferred mechanism.展开更多
Reduced graphene oxide thin films were fabricated on quartz by spray coating method using a stable dispersion of reduced graphene oxide in N,N-Dimethylformamide.The dispersion was produced by chemical reduction of gra...Reduced graphene oxide thin films were fabricated on quartz by spray coating method using a stable dispersion of reduced graphene oxide in N,N-Dimethylformamide.The dispersion was produced by chemical reduction of graphene oxide,and the film thickness was controlled with the amount of spray volume.AFM measurements revealed that the thin films have near-atomically flat surface.The chemical and structural parameters of the samples were analyzed by Raman and XPS studies.It was found that the thin films show electrical conductivity with good optical transparency in the visible to near infrared region.The sheet resistance of the films can be significantly reduced by annealing in vacuum and reach 58 k?with a light transmittance of 68.69%at 550 nm.The conductive transparent properties of the reduced graphene oxide thin films would be useful to develop flexible electronics.展开更多
文摘The complexation of BDHTD （4-benzylidenamino-4,5-dihydro-lH-l,2,4-triazol-5-one derivatives） by divalent doubly charged metal ions M2＋ （M = Mg, Ca, Fe and Cu） has been investigated using the density functional method B3LYP. Two distinct coordination modes （k2-O,O and k2-O,N） have been taken into account. Geometry optimizations have been performed in gas-phase and solution-phase： acetonitrile and DMF （N,N-dimethylformamide） with the basis set 6-31G（d,p）. The B3LYP method was also used to calculate the stability and free energies of the 24 complexes of BDHTD with metal ions M2＋ （M = Mg, Ca, Fe and Cu） respectively in gas-phase and solution-phase： acetonitrile and DMF. Results indicate that k2-O,N structures are most stable in gas-phase. The influence of substitution on the stability is sensitive in solution-phase. The interaction energies of complexation process in various media have been calculated at B3LYP/6-31G（d,p） and CCSD（T） level. The MIA （metal ion affinity） of BDHTD with M2＋ （M = Mg, Ca, Fe and Cu） in various media has been explored. The results show that the M1A highly varies with the coordination mode and substitution effect. From the calculated Gibb energies of complexation in various media, it is revealed that the complexation is possible in gas in acetonitrile. The ligand＇s affinity toward individual cation M2＋ （M = Mg, Ca, Fe and Cu） has been analysed. A significant reduce of BDEs observed confirms the decrease of the antioxidant activity by the metal chelation. The charge transfer induced by metal chelation is examined using the NBO analysis.
文摘In this article, we have performed B3LYP/6-31＋G（d） calculations of geometrical and reaction enthalpies of antioxidant mechanisms for ADPHT 1-4 （3-alkyl-4-phenylacetylamino-lH-1,2,4-triazol-5-ones） and its derivatives： HAT （hydrogen atom transfer）, SET-PT （single electron transfer-proton transfer） and SPLET （sequential proton-loss electron transfer） were investigated in gas and solution-phases. Solvent contribution to enthalpies was computed employing integral equation formalism IEF-PCM （integral equation formalism method） method. It turned out that the lowest BDEs （bond dissociation energies） is obtained for C-H bonds due to captodative effect in various media. Results indicate that HAT mechanism represents the most anticipated process in gas-phase from thermodynamic point of view. But, the SPLET represents the thermodynamically preferred reaction pathway in solvents （2-propanol, acetonitrile, DMF （N,N-dimethylformamide） and water）. The authors showed that bond dissociation energies, IP （ionization potential） and PA （proton affinity） are sufficient to evaluate the thermodynamically preferred mechanism.
基金supported by the National Key Basic Research Program of China(Grant No.2013CBA01703)the National Natural Science Foundation of China(Grant No.11174355)+2 种基金Teknologiateollisuus TT-100the European Union’s Seventh Framework Programme(Grant No.631610)Aalto University(Finland)
文摘Reduced graphene oxide thin films were fabricated on quartz by spray coating method using a stable dispersion of reduced graphene oxide in N,N-Dimethylformamide.The dispersion was produced by chemical reduction of graphene oxide,and the film thickness was controlled with the amount of spray volume.AFM measurements revealed that the thin films have near-atomically flat surface.The chemical and structural parameters of the samples were analyzed by Raman and XPS studies.It was found that the thin films show electrical conductivity with good optical transparency in the visible to near infrared region.The sheet resistance of the films can be significantly reduced by annealing in vacuum and reach 58 k?with a light transmittance of 68.69%at 550 nm.The conductive transparent properties of the reduced graphene oxide thin films would be useful to develop flexible electronics.
