[Ab initio calculations of vibrational frequencies and structures of ion pairs of perchlorate].

Ion association of solutions of lithium perchlorate in N,N-dimethylformamide, acetonitrile, tetrahydrofuran, acetone, methyl acetate and other organic solvents have been investigated by infrared and Raman spectroscopy, respectively. The spectroscopically free ion, contact ion pair and dimer are fingerprint by the curve fitting of upsilon1 band of. The most stable geometries of contact ion pairs and dimmer, and the vibrational frequencies were optimized and calculated using the ab initio methods. The comparison between calculated and experimental data of band position was made. Effect of solvation mode and solvent molecule on the vibrational frequencies of ion pairs was also indicated.