title: UV-induced photochemistry of matrix-isolated 1-phenyl-4-allyl-tetrazolone.
abstract: The photochemistry and molecular structure of 1-phenyl-4-allyl-tetrazolone (PAT) was studied by FT-IR matrix isolation spectroscopy and DFT(B3LYP)/6-311++G(d,p) calculations. The spectrum of matrix-isolated PAT monomers agrees well with the sum spectrum of three conformers predicted theoretically. UV irradiation (lambda > 235 nm) of matrix-isolated PAT induces three types of photofragmentation: (1) production of phenylazide and allyl-isocyanate, with phenylazide then losing N(2) to yield 1-aza-1,2,4,6-cycloheptatetraene; (2) formation of phenyl-isocyanate and allylazide; (3) N(2) elimination leading to formation of 1-allyl-2-phenyldiaziridin-3-one; this compound partially reacts further to form 1-allyl-1H-benzoimidazol-2(3H)-one. The observed photochemistry of the matrix-isolated PAT is distinct from the preferred photochemical fragmentation in solution, where 3,4-dihydro-3-phenylpyrimidin-2(1H)-one is produced as the primary photoproduct.
authors.affiliation: Department of Chemistry and Biochemistry, F.C.T., and CCMAR, University of Algarve, Campus de Gambelas, 8005-039, Faro, Portugal.
authors.forename: L M T
authors.initials: LM
authors.lastname: Frija
authors.forename: I D
authors.initials: ID
authors.lastname: Reva
authors.forename: A
authors.initials: A
authors.lastname: Gómez-Zavaglia
authors.forename: M L S
authors.initials: ML
authors.lastname: Cristiano
authors.forename: R
authors.initials: R
authors.lastname: Fausto
mesh_terms: D015394:Molecular Structure; D010777:Photochemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013777:Tetrazoles / Q000737:chemistry* / Q000528:radiation effects*; D013816:Thermodynamics; D014466:Ultraviolet Rays
chemical_list: D013777:Tetrazoles