title: UV photodissociation of η5-C5H5NiNO: an excited-state Jahn-Teller distortion produces a cartwheeling NO.
abstract: The 225 nm photodissociation of cyclopentadienylnickel nitrosyl was studied using velocity-mapped ion imaging with 1 + 1' REMPI detection of the NO (X (2)Π(1/2,3/2), v'' = 0) photofragment. The product recoil energy and angular distributions were measured for selected rotational states of NO. The NO product displays two speeds, a slow product peaked at the center of the ion image and a fast anisotropic product that has an inverted rotational population. In rotational states above J'' = 40.5, an even faster anisotropic NO photofragment appears, most likely because the metal-containing dissociation partner emerges in a lower electronic state, increasing the available energy. The μ-v-j vector correlations were measured and are consistent with the orientation μ∥v⊥ j. The observed vector correlations arise from an excited-state Jahn-Teller distortion of the parent, a distortion that bends the Ni-NO coordinate prior to dissociation.
authors.affiliation: Department of Chemistry, Kalamazoo College, 1200 Academy Street, Kalamazoo, Michigan 49006, USA.
authors.forename: Amber L
authors.initials: AL
authors.lastname: Peden
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Kieda
authors.forename: Kelsey A
authors.initials: KA
authors.lastname: Breck
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Basore
authors.forename: Caleb A
authors.initials: CA
authors.lastname: Kent
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Bartz
mesh_terms: D003517:Cyclopentanes / Q000737:chemistry; D005454:Fluorescence Polarization; D007834:Lasers; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods; D008956:Models, Chemical; D008968:Molecular Conformation; D009532:Nickel / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010777:Photochemistry; D014466:Ultraviolet Rays
chemical_list: D003517:Cyclopentanes; D009942:Organometallic Compounds; D009569:Nitric Oxide; D009532:Nickel