title: Picosecond time-resolved infrared study of 2-aminopurine ionisation in solution.
abstract: Two photon ionisation of 2-aminopurine (2AP) has been monitored following 267 nm irradiation in neutral and acidic aqueous solutions using picosecond time-resolved infrared spectroscopy (ps-TRIR). The transient infrared spectra obtained in neutral and acidic conditions show significant differences that are consistent with the formation of different species, namely the 2AP radical cation, 2AP+*, in acidic conditions and the uncharged radical, 2AP*(-H+), in neutral conditions. The ps-TRIR data indicate that deprotonation of 2AP+* in neutral solution takes place within <2 ps following photoionisation. DFT calculations (EDF1/6-31+G*) were used to support the assignment of the intermediates observed in these spectroscopic experiments.
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham, UK. m.kuimova@imperial.ac.uk
authors.forename: Marina K
authors.initials: MK
authors.lastname: Kuimova
authors.forename: Peter M W
authors.initials: PM
authors.lastname: Gill
authors.forename: Ching-Yeh
authors.initials: CY
authors.lastname: Lin
authors.forename: Pavel
authors.initials: P
authors.lastname: Matousek
authors.forename: Michael
authors.initials: M
authors.lastname: Towrie
authors.forename: Xue Zhong
authors.initials: XZ
authors.lastname: Sun
authors.forename: Michael W
authors.initials: MW
authors.lastname: George
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Parker
mesh_terms: D015075:2-Aminopurine / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D007700:Kinetics; D015394:Molecular Structure; D012996:Solutions; D013055:Spectrophotometry, Infrared; D013997:Time Factors
chemical_list: D007477:Ions; D012996:Solutions; D015075:2-Aminopurine