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Dipole polarizability of the pyrazabole molecule in solution
Author(s) -
Alvarado Ysaías J.,
Soscún Humberto,
Velazco Wendy,
Labarca Paola H.,
Cubillan Nestor,
Hernández Javier
Publication year - 2002
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.555
Subject(s) - polarizability , chemistry , dipole , computational chemistry , ab initio , cyclohexane , extrapolation , ab initio quantum chemistry methods , solvent effects , molecular physics , molecule , solvent , organic chemistry , mathematical analysis , mathematics
The dynamic and static dipole polarizabilities of pyrazabole (PYRZ) were investigated using a refractometric method and theoretical calculations. The experimental properties were studied within the Singer–Garito and Proutiere and co‐workers' approaches for dilute cyclohexane, THF and CH 3 CN solutions. These methodologies were appropriate to quantify the electronic polarizability and electric deformability of pyrazabole in the optical regime. The static dipole polarizabilities of pyrazabole were obtained from extrapolation to zero frequency of the corresponding dispersion Cauchy‐type curves, which gave a monotonic increasing in function of the squared frequency. The differences between these curves were analyzed as a function of the solvent effects. Additionally, a comparative study with pyrazole was carried out. The results indicated that both the static and dynamic electronic polarizability of pyrazabole are determinated from the linear optical response of the pyrazole ring. In fact, the polarizability of the two pyrazole rings is approximately 80% of the overall value for pyrazabole. The theoretical static properties were evaluated by using ab initio (Hartree–Fock) and DFT (B3LYP) methods with the 6–31+G(d,p) and 6–311++G(3d,3p) basis sets. The calculations were performed with fully optimized geometries. The B3LYP average static electronic polarizability value of pyrazabole is 1.877 × 10 −23 esu, and the differences from the experimental static values are within −1.2 to 8.5%. These variations are mainly due to the solvent effects. Copyright © 2002 John Wiley & Sons, Ltd.