posted on 2017-03-31, 00:00authored byJovanny A. Gómez
Castaño, Rosana M. Romano, Carlos O. Della Védova, Helge Willner
The
photochemistry of OCSe with ClF trapped together in argon matrices
at cryogenic temperatures has been explored and the first interhalogen
representatives of the elusive XC(O)SeY family, namely syn-ClC(O)SeF, anti-ClC(O)SeF, syn-FC(O)SeCl, and anti-FC(O)SeCl, as well as the hitherto
triatomic species ClSeF complexed by a CO molecule, were obtained.
Both ClC(O)SeF conformers appear to be produced independently by photolysis
of the respective precursors; while formation of both FC(O)SeCl structures
is ruled by the presence of an angular molecular complex OCSe···Cl–F
formed prior to photolysis. This latter photochemical pathway seems
to favor the formation of the less stable anti-FC(O)SeCl
structure instead of the more stable syn- one. With
the aid of quantum chemical calculations, using ab initio, DFT, TDDFT, and CASSCF methods, the mechanism for this photochemical
reaction is rationalized both in terms of radical processes as well
as a photoinduced electron transfer occurring into the OCSe···Cl–F
complex. Also a singlet–triplet conical intersection between anti and syn rotamers of the FC(O)SeCl
molecule is theoretically explored.