| Abstract: | Structural aspects of polymorphism are studied for homologous series of alkylbenzoic acids with a completely or partially fluorinated alkyl radical. IR absorption spectra were measured in the range 60-4000 cm−1 at 100–500 K. The spectra were interpreted by computer simulation on a PC with LEV-100 software realizing the fragmentary approach to solving the mechanical and optoelectronic problems by the method of M. V. Volkenshtein, M. A. El’yashevich, L. A. Gribov, and B. I. Stepanov. The previous assumptions that the samples possess conformational mobility and are conformationally nonhomogeneous are confirmed by comparing the spectra of the title compounds measured at different temperatures with those calculated for conformer models with different degrees of twisting of fluoroalkyl radicals and their different orientations relative to the other part of the complex. N. G. Chernyshevskii Saratov State University. Institute of Physics, Ukrainian Academy of Sciences (Kiev). Translated fromZhurnal Strukturnoi Khimii, Vol. 39, No. 3, pp. 522–528, May–June, 1998. This work was supported by RFFR grant No. 97-03-32175a. |
