The molecular structure of cis-FONO

Abstract

The molecular structure of cis-FONO has been determined with the CCSD(T) correlation method using an spdf quality basis set. In agreement with previous coupled-cluster calculations cis-FONO exhibits normal bond distances. The cubic force field of cis-FONO has been determined in order to evaluate the effect of vibrational averaging on the geometry. Vibrational averaging is found to increase bond distances, as expected, but it does not affect the qualitative description of the bonding. The CCSD(T)/spdf harmonic frequencies of cis-FONO support our previous assertion that a band observed at 1200 cm-1 is a combination band (ν3 + ν4), and not a fundamental. In contrast to earlier density functional theory (DFT) studies, calculations using an empirically optimized hybrid functional give a structure and vibrational frequencies for cis-FONO that are in qualitative agreement with the CCSD(T) values, resolving the discrepancy between DFT and CCSD(T). © 1994.