Density functional study of the molecular structures,infrared and Raman spectra of carbon suboxide,its sulfur and selenium analogues

Carbon suboxide, and its sulfur and selenium analogues in D _∞h symmetry have been studied in the gas phase by a density functional method using B3LYP as the functional. The basis sets employed are 6-31++G(d,p), 6-311++G(d,p), cc-pVDZ and all calculations have been carried out using Gaussian 03W. Molecular parameters, namely bond lengths, rotational constants, quadrupole moments, and infrared and Raman frequencies are predicted for these molecules. Atomization energies have also been predicted. The calculated molecular parameters and vibrational spectra of the parent molecule, namely carbon suboxide, are in good agreement with literature data. Therefore, data from the present theoretical gas phase study are expected to be valid for the molecular structures and vibrational spectra of carbon subsulfide and carbon subselenide. The results from this study could be used as a reference for these molecules.