Early barriers in the matrix photochemical formation of syn-anti randomized FC(O)SeF from the OCSe:F2 complex

JOVANNY A. GÓMEZ CASTAÑO; A. LORENA PICONE; ROSANA M. ROMANO; HELGE WILLNER; CARLOS O. DELLA VÉDOVA

CHEMISTRY-A EUROPEAN JOURNAL

Año: 2007 vol. 13 p. 9255 - 9361

0947-6539

The photochemically induced reaction of OCSe and F2, isolated together in an Ar matrix at about 15 K, leads to formation of the hitherto-unknown fluorocarbonylselenyl fluoride FC(O)SeF. The reaction occurs via a van der Waals complex O=C=Se···F
F that favors very early formation of the anti conformer. The presence and subsequent decay of a band assigned to the F
F vibration correlated with perturbed OCSe bands seems to confirm this hypothesis. Subsequent irradiation of the matrix leads to randomized FC(O)SeF by a photochemically induced conformational equilibrium between syn and anti forms. Another photochemical reaction channel is the formation of CO and SeF2 molecules, which are produced in the same matrix cage and then form a loose complex. The changes were monitored and the products characterized experimentally by their IR spectra, and the spectra analyzed in the light of the results of theoretical calculations.