UV-induced photochemistry of matrix-isolated 1-phenyl-4-allyl-tetrazolone.
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.
Frija
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LM
Department of Chemistry and Biochemistry, F.C.T., and CCMAR, University of Algarve, Campus de Gambelas, 8005-039, Faro, Portugal.
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Gómez-Zavaglia
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Cristiano
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Fausto
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D015394:Molecular Structure; D010777:Photochemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013777:Tetrazoles / Q000737:chemistry* / Q000528:radiation effects*; D013816:Thermodynamics; D014466:Ultraviolet Rays
D013777:Tetrazoles