New insights into the Ar-matrix-isolation FTIR spectroscopy and photochemistry of dichloroacetyl chloride, ClC(O)CHCl2: Influence of O2 and comparison with gas-phase photochemistry

Photolysis products of dichloroacetyl chloride (DCAC) isolated in Ar matrix and gas phase, the absence presence molecular oxygen, were studied by means FTIR spectroscopy. The samples exposed to light different energy ranges (200–800, 280–320, 350–450 400–800 nm). DCAC is photostable when irradiated with wavelengths above 400 nm, gives dichloroketene after photolysis between 280–320 nm. Exposure broad-band radiation (200–800 nm) produces as an intermediate photoproduct, 1:1 CHCl3:CO complexes further irradiation. HCl, CO CHCl3 detected gas-phase photolysis. ClC(O)CCl2CCl2H molecule was also proposed, a mechanism that involve insertion of:CCl2 biradical into C−C bond DCAC. photochemical reaction O2 Cl2CO CO2. same photoproducts, together observed reaction. Additionally, spectra solid fully interpreted terms equilibrium syn (the H−C respect C=O bond) gauche conformers. Some absorptions, which grow DCAC:Ar ratio increases, attributed dimeric forms. most stable dimer predicted DFT calculations composed two molecules conformations, interacting through H-bonds structure Ci symmetry.