title: Aggregation models of potential cyclical trimethylsulfonium dicyanamide ionic liquid clusters.
abstract: Raman and infrared spectra of trimethylsulfonium dicyanamide [(CH(3))(3)SN(CN)(2)] are reported and accurately reproduced by DFT methods (B3LYP and B3PW91), MP2, and MP3, and to a lesser extent by the RHF method. The (CH(3))(3)SN(CN)(2) ionic liquid forms two isomeric dimers that are of cyclic structure, one of which is 13 kcal/mol lower in energy than the other. Both isomeric cyclic pairs (versions 1 and 2), [(CH(3))(3)SN(CN)(2)](2), have the potential to further combine and form a common structure containing four pairs of (CH(3))(3)SN(CN)(2). This structure can then conceivably undergo a stacking procedure to form extended ionic liquid nanotubes of eight ionic liquids, [(CH(3))(3)SN(CN)(2)](8). The possible formation of gas phase ionic liquid clusters of two, four, and eight trimethylsulfonium dicyanamide ionic liquids is supported by highly exergonic free energy changes obtained from B3LYP/(6-311+G(d,p)) density functional calculations.
authors.affiliation: Department of Chemistry, Wichita State University, Wichita, Kansas 67260-0051, USA. Bob.Carper@wichita.edu
authors.forename: W Robert
authors.initials: WR
authors.lastname: Carper
authors.forename: Kevin
authors.initials: K
authors.lastname: Langenwalter
authors.forename: Naveed S
authors.initials: NS
authors.lastname: Nooruddin
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kullman
authors.forename: Dirk
authors.initials: D
authors.lastname: Gerhard
authors.forename: Peter
authors.initials: P
authors.lastname: Wasserscheid
mesh_terms: D003198:Computer Simulation; D005740:Gases / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D013452:Sulfonium Compounds / Q000737:chemistry*
chemical_list: D005740:Gases; D052578:Ionic Liquids; D009570:Nitriles; D013452:Sulfonium Compounds; C540045:trimethylsulfonium dicyanamide