Theoretical Investigation on C11H8 Bicyclic Carbene and Allene Isomers

Recent studies postulate that the presence of polycyclic aromatic hydrocarbons (PAHs) in interstellar medium (ISM) could have been formed through resonance-stabilized arylcarbene intermediates. However, identifying most these reactive intermediates is very challenging experimentally due to their metastability and other experimental constrains. Thus, computational cover thermodynamic versus kinetic stability various possible structures would be beneficial for successfully new molecules either laboratory and/or ISM. In this paper, more than four hundred C 11 H 8 carbene isomers theoretically investigated employing density functional theory (DFT). Hybrid functionals B3LYP ωB97XD with 6-311 + G (d,p) basis set used singlet electronic states, whereas, triplet spin states were optimized at same level using an unrestricted Hartree-Fock wavefunction. Although skeletal can categorized into monocyclic, bicyclic, tricyclic, tetracyclic acyclic isomers, bicyclic carbenes shown better resonance stabilized azulenyl/naphthyl rings. category, some (1-, 2-, 5- 6-azulenylcarbenes 1- 2-naphthylcarbenes) also detected recently simple such as cyclopropenylidene its homologues are we systematically energetic spectroscopic properties 5-, 6-, 7- 8-membered ring containing fingerprint regions infrared spectrum each class compounds.