title: Exploring the nature of interactions among thiophene, thiophene sulfone, dibenzothiophene, dibenzothiophene sulfone and a pyridinium-based ionic liquid.
abstract: In order to gain an understanding of the nature of the interactions among thiophene (TS), thiophene sulfone (TSO2), dibenzothiophene (DBT), dibenzothiophene sulfone (DBTO2) and the ionic liquid N-butylpyridinium hydrogen sulfate ([BPY][HSO4]), a systematic investigation has been carried out using ab initio methods. The most stable structures indicate that both [BPY](+) and [HSO4](-) play crucial roles in the interactions between TS, TSO2, DBT, DBTO2 and [BPY][HSO4]. Analyses of the most stable optimized structures suggest the occurrence of steric effects, π-π stacking effects, hydrogen bonds, and dihydrogen bonds. The π-π stacking effect in [BPY][HSO4]-TSO2/[BPY][HSO4]-DBTO2 is less significant than that in [BPY][HSO4]-TS/[BPY][HSO4]-DBT, as TSO2 and DBTO2 are more nucleophilic than TS and DBT, resulting in stronger interactions between [BPY][HSO4] and TSO2/DBTO2 than between [BPY][HSO4] and TS/DBT. Thermodynamical data also demonstrate that TSO2/DBTO2 are more prone to interact with [BPY][HSO4] compared with TS/DBT.
authors.affiliation: College of Science, China University of Petroleum (East China), 266580, Qingdao, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Gu
authors.forename: Renqing
authors.initials: R
authors.lastname: Lü
authors.forename: Dong
authors.initials: D
authors.lastname: Liu
authors.forename: Yukun
authors.initials: Y
authors.lastname: Lu
authors.forename: Shutao
authors.initials: S
authors.lastname: Wang