Using molecular graphics software, we have designed numerous models of CnP5- (n=1-7). We carried out geometry optimization and calculation on vibrational frequency by means of the B3LYP density functional method. After comparing the total energies of the isomers, we found that the ground state structures are straight carbon chains with a P4C ring connected at one end and a phosphorus atom at the other. The alternate behaviours in electron affinity, bond length, and incremental binding energy with odd and even "n" match the peak pattern observed in the laser-induced mass spectra of CnP5- (n=1-7) and the results of experimental reactions. When n is even, the electron state is 1A1, whereas it is 3A2 with odd n. The bond lengths of straight Cn chains show a polyacetylene-like structure. As for the C-P bonds within the straight chains, there is an alternate pattern in length, i.e., compared to the C-P bonds at even n, those at odd n show a bigger bond length.
Scopus Subject Areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Binary cluster anions
- Density functional study
- Phosphorus-doped carbon clusters