RAMAN-SCATTERING SPECTRA OF SODIUM N-BUTYL(N-HEXYL) PHOSPHATE AGGREGATES AND CONFORMATION ABOUT THE PHOSPHODIESTER P-O BONDS IN COAGEL PHASES

A new double-chain surfactant molecule, sodium n-butyl(n-hexyl)phospha te (BHP), having an asymmetric molecular structure, has been synthesiz ed. For anhydrous BHP in the solid state and the BHP-H2O system in the lyotropic liquid crystalline and coagel states, the Raman scattering spectra arising from the accordion vibrational mode were studied in th e temperature range - 170 to 25 degrees C. For anhydrous BHP, the GG f orm about the phosphodiester P-O bonds was preferentially stabilized a t lower temperature. In the coagel phase of the BHP-H2O system, prefer ential stabilization of a specific conformation about the P-O bonds oc curred and which molecular form was stabilized was dependent on the wa ter content: for the 8:2 BHP-H2O sample in the coagel the GT form was stabilized, while for the 7:3 BHP-H2O coagel sample the TT form was pr eferentially stabilized. The stabilization of such a specific conforma tion was also reflected in the higher-frequency region.