Photoinduced Formation of H-Bonded Ion Pair in HCFC-133a.

High-level multireference electronic structure calculations have been performed to study the Cl yield from photoexcited CFCHCl (HCFC-133a). The analysis of this process tells that it relates to an electron transfer from the carbon to the Cl atom, forming a highly polar contact ion-pair complex, CFHCH···Cl, in the excited (S) state. This complex has a strong binding energy of 3.