Thin Solid Films, Vol.325, No.1-2, 210-217, 1998
Molecular recognition of nucleolipid amphiphile octadecanoyl ester of 1-(2-carboxyethyl) adenine to the complementary nucleobases : Part II. a Fourier transform infrared spectroscopic study of Langmuir-Blodgett films
Fourier transform infrared (FTIR) transmission, polarized transmission and attenuated total reflection (ATR) spectroscopy were employed to investigate the molecular recognition capabilities of a novel nucleolipid amphiphile, octadecanoyl eater of 1-(2-carboxyethyl) adenine, to the complementary nucleobases, thymidine and uridine, in the Langmuir-Blodgett film matrix. A broad band observed in the 3500-3000 cm(-1) region indicated the formation of the multiple hydrogen bonding between the adenine moiety in the headgroup of the nucleolipid amphiphile and the corresponding complementary nucleobase in the subphase was observed, which verified the molecular recognition mechanism suggested in the previous paper. In the thymidine-containing LB films of the nucleolipid amphiphile, the molecules are biaxially oriented, while in the uridine-containing LB films, the molecules are uniaxially oriented; similar to the LB films transferred from pure water, the corresponding anisotropy and isotropy were detected via FTIR polarized transmission spectroscopy. This is due to the steric effect caused by the methyl of the thymine ring. The order-disorder transitions of the LB films deposited from various subphases were investigated by using FTIR transmission spectroscopy. The results show that the existence of the complementary nucleobases in the LB films has little influence on the arrangement of the hydrocarbon chains of the nucleolipid amphiphile. The no-complementary base-containing and complementary base-containing LB films of the nucleolipid amphiphile all display high thermal stability.