title: Imide photodissociation investigated by X-ray absorption spectroscopy.
abstract: X-ray absorption spectroscopy is used to investigate the photodissociation of the imides PMDI (pyromellitic diimide) and SSMCC (sulfosuccinimidyl 4-(N-maleimidomethyl) cyclohexane-1-carboxylate). PMDI contains only one type of imide, and its photodissociation can be explained by a simple conversion from imide to a mix of imine and nitrile after desorption of the oxygens from the imide. SSMCC contains two different imides. One reacts like PMDI, the other in a more complex multistep process. Eventually, N(2) is formed in the bulk of the sample at high radiation density. The sequence of reactions is inferred from the π* peaks in total electron yield and fluorescence yield absorption spectra at the N 1s and O 1s edges. First-order rate equations are used to model the evolution of the peak areas versus radiation dose.
authors.affiliation: Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Phillip S
authors.initials: PS
authors.lastname: Johnson
authors.forename: Peter L
authors.initials: PL
authors.lastname: Cook
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Liu
authors.forename: Wanli
authors.initials: W
authors.lastname: Yang
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Bai
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Abbott
authors.forename: F J
authors.initials: FJ
authors.lastname: Himpsel