jp066188b_si_001.pdf (162.71 kB)
Conformers and Photochemistry of Propyl Nitrites: A Matrix Isolation Study
journal contribution
posted on 2007-01-25, 00:00 authored by Edit Mátyus, Gábor Magyarfalvi, György TarczayThe infrared spectra of both constitutional isomers (n and i) of propyl nitrite have been recorded in an Ar
matrix. Conformational analysis and assignments of the vibrational transitions have been carried out on the
basis of quantum chemical calculations. Assignment of spectral lines to different conformers was also aided
experimentally, by utilizing the different rate of photodecomposition of the conformers, as well as by employing
conformational cooling using a supersonic jet as the inlet source for matrix deposition. The rate of
photodecomposition is primarily determined by the steric alignment of the nitrite group, whereas jet cooling
affects mainly the conformation of the alkyl tail. On the basis of these experimental observations and
computational predictions two to three conformers of isopropyl nitrite and eight conformers of n-propyl nitrite
were identified. After broadband ultraviolet−visible (UV−vis) photolysis of isopropyl nitrite in the matrix,
HNO, acetone, HNO·acetone complex, acetaldehyde, and nitrosomethane were identified as the main products.
Furthermore, in a small amount, NO and possibly the isopropoxy radical were also present in the matrix.
Photolysis of n-propyl nitrite yielded HNO, propanal, and their 1:1 complex as the main products together
with a small amount of NO and cis-1-nitrosopropanol.