Vibrational spectra of cyclic C8 in solid argon

Vapors from solid and powdered carbon, emitted from an oven cycled between 2000 and 3000 K, were co-condensed with argon onto a CsI substrate maintained at 10 K. The cycling process produced a multilayered matrix with regions of high carbon density alternating with layers of argon. FTIR measurements including 13C isotopic data, supported by ab initio calculations, allow the assignment of a band observed at 1817.8 cm−1 to the ν12(eu) fundamental of cyclic C8.