title: Far-UV photochemical bond cleavage of n-amyl nitrite: bypassing a repulsive surface.
abstract: We have investigated the deep-UV photoinduced, homolytic bond cleavage of amyl nitrite to form NO and pentoxy radicals. One-color multiphoton ionization with ultrashort laser pulses through the S(2) state resonance gives rise to photoelectron spectra that reflect ionization from the S(1) state. Time-resolved pump-probe photoionization measurements show that upon excitation at 207 nm, the generation of NO in the v = 2 state is delayed, with a rise time of 283 (16) fs. The time-resolved mass spectrum shows the NO to be expelled with a kinetic energy of 1.0 eV, which is consistent with dissociation on the S(1) state potential energy surface. Combined, these observations show that the first step of the dissociation reaction involves an internal conversion from the S(2) to the S(1) state, which is followed by the ejection of the NO radical on the predissociative S(1) state potential energy surface.
authors.affiliation: SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Minitti
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Martin
authors.initials: M
authors.lastname: Rosenberg
authors.forename: Rasmus Y
authors.initials: RY
authors.lastname: Brogaard
authors.forename: Sanghamitra
authors.initials: S
authors.lastname: Deb
authors.forename: Theis I
authors.initials: TI
authors.lastname: Sølling
authors.forename: Peter M
authors.initials: PM
authors.lastname: Weber
mesh_terms: D000680:Amyl Nitrite / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D007700:Kinetics; D013058:Mass Spectrometry; D009569:Nitric Oxide / Q000737:chemistry; D010432:Pentoxyl / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D010782:Photolysis; D011789:Quantum Theory; D013499:Surface Properties; D014466:Ultraviolet Rays
chemical_list: D005609:Free Radicals; D009569:Nitric Oxide; D010432:Pentoxyl; D000680:Amyl Nitrite