Photoisomerization of IC3N. An experimental and theoretical study

Abstract Here we present the results of a joint spectroscopic and quantum chemical study on the photochemistry of 3-iodo-2-propynenitrile (iodocyanoacetylene, IC3N). Vacuum-UV photolysis of the compound isolated in solid argon was explored. Calculations, carried out at the DFT and/or coupled-cluster level of theory, provided essential data concerning the thermodynamic stabilities, vibrational and electronic energy levels, ionization potentials, and electron affinities of IC3N-stoichiometry isomers and ions. The photochemical formation of thus far unknown species IC2NC and ICNC2 has been evidenced by the experiment and rationalized based on a detailed theoretical approach, involving the excited-state potential energy surfaces.