title: A combined experimental and theoretical study of the Ti2 + N2O reaction.
abstract: The reactivity of diatomic titanium with nitrous oxide has been studied in solid neon. Two molecules with the same Ti2-N2O stoichiometry are identified from concentration, temperature, and irradiation effects. The more stable one is characterized by five fundamental vibrational transitions located below 1000 cm(-1), the high frequency one at 946 cm(-1) corresponding to a pure TiO stretching mode. Its structure, a rhombus OTiNTiN with the extra O atom fixed on one Ti, is confirmed by quantum chemical calculations, at the CCSD(T) level, which predict a Cs structure in the singlet state with a Ti-O bond length close to 1.66 Å, two nonequivalent Ti-N distances close to 1.94 and 1.75 Å, and a OTiTi angle of 119.2°. The second Ti2-N2O molecule, only observed after annealing, is easily converted into the first one upon irradiation above 12 000 cm(-1) and its kinetics of photoconversion allows vibrational transitions to be identified. The strongest one located at 2123.4 cm(-1) characterizes an N-N stretching mode. Corresponding ab initio calculations complete this picture with details on the electronic structure and allow us to identify a most adequate density functional to describe the spectroscopic properties of the studied species in a simpler broken-symmetry open-shell DFT context. The theoretical results predict the existence of a metastable product OTi2N2 and correctly account for the observed spectra of the various isotopic varieties.
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, UMR 7075, LADIR (MONARIS, UMR 8233), Université Pierre et Marie Curie , 4 Place Jussieu, case courrier 49, F-75252 Paris Cedex 05, France.
authors.forename: A
authors.initials: A
authors.lastname: Marzouk
authors.forename: H
authors.initials: H
authors.lastname: Bolvin
authors.forename: P
authors.initials: P
authors.lastname: Reinhardt
authors.forename: L
authors.initials: L
authors.lastname: Manceron
authors.forename: J P
authors.initials: JP
authors.lastname: Perchard
authors.forename: B
authors.initials: B
authors.lastname: Tremblay
authors.forename: M E
authors.initials: ME
authors.lastname: Alikhani