吡啶基离子液体与噻吩类化合物相互作用的理论研究

采用密度泛函理论考察了N-丁基吡啶醋酸盐离子液体(［BPY］［Ac］)和噻吩(TS)、苯并噻吩(BT)、二苯并噻吩(DBT)、萘(NAP)的相互作用，并进行了NBO和AIM分析。［BPY］［Ac］离子对最稳定的结构表明，［Ac］阴离子的O原子优先与吡啶环上C2—H2发生氢键作用。在分子水平上，NBO和AIM分析证实了TS、BT、DBT、NAP和［BPY］［Ac］中的阴离子发生氢键作用、与吡啶环发生π…π相互作用，阴、阳离子均影响脱硫效果。但NAP与阴离子的氢键作用、与吡啶环π…π相互作用较弱，造成NAP与［BPY］［Ac］相互作用能小，而DBT则优先吸附在［BPY］［Ac］离子液体上。

Theoretical Study on Interactions Between Pyridinium-Based Ionic Liquids and Thiophenic Compounds

The interactions between thiophene(TS), benzothiophene(BT), dibenzothiophene(DBT), naphthalene(NAP) and N-butylpyridinium acetate(［BPY］［Ac］) were investigated by density functional theory, and analyzed by NBO and AIM methods. The most stable gas phase structure of ［BPY］［Ac］ ion pair indicated that hydrogen bonding interactions between O atoms on ［Ac］^- anions and C2—H2 on the pyridinium ring played a dominating role in the formation of ion pair. The π…H—C, π…π and hydrogen bonding interactions occur between ［BPY］［Ac］ and TS, BT, DBT, NAP, which were proved by NBO and AIM analysis at the molecular level. The π…π and hydrogen bonding interactions between ［BPY］［Ac］ and NAP were weak in terms of structural properties. The interaction energies suggested that DBT is prior to adsorption on ［BPY］［Ac］ ionic liquid.