C_6H_5COOH…X分子间氢键的理论研究

Theoretical study on intermolecular hydrogen bond of C_6H_5 COOH…X

在B3LYP/6-311++G(3df,2p)理论水平,计算研究C_5H_5COO-H…X(X=H_2O,HC(OH,CH_3COCH_3,NH_3,CH_2NH和HCN)氢键体系.获得氢键复合物稳定结构、氢键相互作用能、振动频率、热力学性质等.计算结果表明,C_6H_5 COO-H…X体系存在较强的(O—H…O与O—H…N红移氢键.C_6H_5COO—H…X氢键复合物气态分子的自发形成过程温度不同,C_6H_5COOH…NH_3和C_6H_5COOH…CH_2NH体系在室温下能自发进行,其余二聚体要在低温下才能自发进行.

The H-bonding dimers ofC6H5COO-H…Xwere studied using density functional theory （DFT） at B3LYP/6-311＋＋G（3df,2p） level. The stable structure, interaction energy, vibration fre- quency and thermodynamic properties ofC6H5COO-H…X H-bonding dimers had been obtained. The results showed that strong O-H… O and O-H…N red-shift hydrogen-bond existed inC6H5COOH…X -bonding dimers. The spontaneous forming processes of different C6H5COO-H…X H-bonding di- mers in gas state needed different temperatures. The spontaneous forming processes ofC6H5COOH…X NH3 and C6H5COOH…XCH2NH could be aroused at room temperature; but others needed low tempera- tures.