Vibrational frequencies and structure of cyclopropenone from ab initio calculations

Several calculations with different basis sets have been carried out to better understand the unusual vibrational frequencies of cyclopropenone. It is shown that the bands at 1840, 1483, and 1026 cm(-1) are predominantly the C=O, C=C, and symmetric C-C stretches. However, for the first and last of these there is strong interaction between the C=O and C-C stretches. The results differ quantitatively from a previous normal coordinate calculation and interpretation. (C) 2004 Elsevier B.V. All rights reserved.