title: A comparative study on the ionic liquid [bmim][BF4] and its solution with transient absorption spectroscopy.
abstract: A detailed study was explored to compare the transient absorption spectra of the neat 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF(4)]) with its solution in water or acetonitrile. It was concluded that the excited triplet state (3)[bmim](+*) was produced after 266 nm laser irradiation, and then the neutral radical [bmim] and the cation radical [bmim] (2+) were formed through two possible paths. The transient absorption spectra of the neat [bmim][BF(4)] and its solution were similar but the reaction kinetics were different due to their different local structures such as dimeric or cluster. The energy transfer between excited [bmim][BF(4)] and β-carotene further affirmed the existence of (3)[bmim](+*). And the reaction that the hydrated electron captured by [bmim](+) to produce [bmim] in solution was observed.
authors.affiliation: Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu 241000, PR China.
authors.forename: Guanglai
authors.initials: G
authors.lastname: Zhu
authors.forename: Guozhong
authors.initials: G
authors.lastname: Wu
authors.forename: Xinsheng
authors.initials: X
authors.lastname: Xu
authors.forename: Xuehan
authors.initials: X
authors.lastname: Ji
mesh_terms: D000097:Acetonitriles / Q000737:chemistry*; D001881:Borates / Q000737:chemistry*; D019281:Dimerization; D004583:Electrons; D004735:Energy Transfer; D005459:Fluorides / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D007477:Ions; D007700:Kinetics; D007834:Lasers; D010777:Photochemistry / Q000379:methods*; D010782:Photolysis; D012996:Solutions; D013053:Spectrophotometry / Q000379:methods; D014867:Water / Q000737:chemistry; D019207:beta Carotene / Q000737:chemistry
chemical_list: C419324:1-butyl-3-methylimidazolium tetrafluoroborate; D000097:Acetonitriles; D001881:Borates; D007093:Imidazoles; D052578:Ionic Liquids; D007477:Ions; D012996:Solutions; D019207:beta Carotene; D014867:Water; D005459:Fluorides; C032159:acetonitrile