离子液体[bmim][PF6]与乙腈混合体系中的激光光解研究

以蒽醌(AQ)作为探针分子,利用激光光解技术研究了咪唑型离子液体1-丁基-3-甲基咪唑六氟化磷(bmim]PF6])与乙腈(MeCN)混合体系中的光化学反应行为.研究结果表明,离子液体bmim]PF6]自身可与激发三线态的蒽醌分子(3AQ*)进行反应,且表观反应速率常数随着bmim]PF6]/MeCN比例的不同呈现特殊规律性的变化.在离子液体的摩尔分数(xRTIL)为0.06处观察到一个明显的临界点.当xRTIL＜0.06时,表观速率常数随xRTIL的增大而增大;而当xRTIL＞0.06时,表观速率常数随xRTIL的增大而减小.文章给出了bmim]PF6]/MeCN混合体系中激光诱导化学反应的动力学常数,并初步推测了其反应机理,进一步揭示了离子液体bmim]PF6]的一些新的光化学特性.

Laser Photolysis Study on Photochemical Reactions in Mixed Solutions of Laser [bmim][PF6] and Acetonitrile

Laser flash photolysis study was carried out for the first time in the binary mixture of room-temperature ionic liquid(RTIL)and traditional organic solvent.Photochemical properties of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate bmim]PF6] and its binary mixed solutions with MeCN were investigated by laser photolysis technique at an excitation wavelength of 355 nm,using anthraquinone(AQ)as a probe molecule.It was indicated that bmim]PF6] itself participates in the reaction with 3AQ.Moreover,along with the change in the ratio of RTIL to organic solvent,the decay reaction rate constant of 3AQ changes regularly and a critical point was observed at xRTIL=0.06.Before the critical point,the decay rate constant increases rapidly with increasing xRTIL;however,it decreases obviously with increasing xRTIL after the critical point.The kinetic data are given,and the possible reaction mechanisms in mixed solutions are also speculated.