GEOMETRIES AND VIBRATIONAL FREQUENCIES OF OXYACIDS AND CARBOXYLIC-ACIDS - A STUDY ON STRUCTURAL AND VIBRATIONAL EFFECTS

The equilibrium geometries of the acids H3BO3, H2CO3, HNO2, HNO3, HPO3, HClO4, H2SO4, CH3SO3H, CF3SO3H, FSO3H, ClSO3H, H2SeO4, H3PO4. HCO2H, HCOOOH and C6H5CO2H, and of the anions H2BO3-, HBO32-, BO33-, HCO3-, HSO4-, CH3SO3-, CF3SO3-, FSO3-, ClSO3-, HSeO4 , HPO42-, H2PO4-, PO43-, HCO2-, HCOOO- and C6H5CO2- were determined at the self-consistent field (SCF) level, employing polarized split-valence basis sets. The MP2/6-31G** level was adopted to optimize the geometries of H3BO3, HBO2, H2CO3, HNO3, HPO3, HNO2, HCO2H and HCOOOH; those of the anions H2BO3-, HBO32-, HCO3-, HCO2- and HCOOO- were studied at the MP2/6-31G** level. The last section of the study reports the results of SCF calculations on the hydrogen-bonded complexes (HCO2-) (H2O), (CO32-) (H2O) and (HCO3-) (H2O).