FOURIER-TRANSFORM INFRARED SPECTROSCOPIC INVESTIGATION ON LANGMUIR-BLODGETT-FILMS OF OCTADECANOYL ESTER OF 1-(2-CARBOXYETHYL) THYMINE - MOLECULAR-ORIENTATION, MOLECULAR RECOGNITION TO COMPLEMENTARY BASE OF NUCLEIC-ACID AND ORDER-DISORDER TRANSITION

Fourier transform infrared (FTIR) transmission, polarized transmission , reflection absorption (RA) and Attenuated total reflection (ATR) spe ctroscopy were employed to investigate the molecular orientation and m olecular recognition to the complementary base at the air/water interf ace of a novel nucleolipid amphiphile, octadecanoyl ester of 1-(2-carb oxyethyl) thymine. It has been found that the molecules ape biaxially oriented and the hydrocarbon chain titled considerably from the substr ate normal as well as the chromophoric part in the LB film. Molecular recognition through complementary bases pairing takes place at the air /water interface between the thymine moiety in the head group of the a mphiphile and adenosine in the subphase, the hydrogen involved in the host-guest interactions has been detected by using FTIR-ATR technique. FTIR transmission spectra measured at elevated temperatures revealed that the order-disorder transition of the LB film which contains the c omplementary base occurs at lower temperature. To our best knowledge, investigation of the order-disorder transitions in nucleolipid amphiph ile LB films and comparative studies of the order-disorder transitions between nucleolipid amphiphile LB film that contains and does not con tain the complementary bases have been virtually nonexistent, so far.