Theoretical study of the low-lying electronic states of CCCF radical and its ions

A THEORETICAL STUDY OF CARBON CHAINS OF TYPE CNF(N = 1–7) IN NEUTRAL AND IONIC FORMS

The structures, binding energies, and molecular parameters of C n F clusters (n = 1–7) have been investigated theoretically on neutral and ionic forms with the RCCSD(T)//B3LYP/aug-cc-pVTZ level of theory. It can be concluded that for the ground states the linear structures are stable only for CF , C 6 F , and C 7 F . Other neutral species of C n F (n = 2–5) are slightly bent. The variation in stability with growth of the carbon chain is flat but the ionization potential and electron affinity exhibit clear variations with the size of the clusters. Cation clusters with an even n value have triplet ground states whereas singlet ground states exist when n is odd. All anions except CF -, have singlet ground states. The alternation in stability is found in both cationic and anionic forms, but the trends are reversed. Predictions of several molecular properties may be useful in the identification of these species in the laboratory and in space.