| Ferrocene (Fc) derivatives are expected to have potential applications in informational optics, communication and integrated optics so that there has been a great deal of interests in recently years. However, Fc derivatives could not be used as functional molecules directly in many high-tech fields such as nonlinear optics, light emitting devices, sensors and so on. Only when they are organized with some structure or dispersed homogeneously into solid matrix to form functional material, their function could be fully brought into play. In the realization of molecule function, the essential material is thin organic film. In attempting to construct ordered arrays of organic molecules it is obvious that one can only employ Langmuir-Boldgett technique.In this paper, a new amphiphilic molecule (N, N-dimethylferrocenylmethylhexad -ecylammonium bromide, FC16AB) with Fc moiety as the head group was synthesized and characterized by FT-IR, H1NMR, ESMS etc. The studies about electron level structure and surface activity of FCi&AB are carried in detail at first. The studies show they are practical and promising functional molecules for opto-electronics.The following works put FC16AB to study physical chemistry properties of its monolayer and LB films with other molecules. The conclusions are as listed below:The surface pressure-molecular area ( -A) isotherms of FC16AB and hexadecyltrimethylammonium bromide (CTAB) on aqueous subphases were studied. The results demonstrated that the orientation of Fc moiety within FC16AB monolayer changed and the angle between the interface and cyclopentadienyl ring from 70 to the cyclopentadienyl ring parallel to the air/water interface. The compressibility of FC16AB monolayer increased with the concentration of Cl- increasing on the subphase containing counterions. The compressibility of FC16AB monolayer and the angle of Fc contacting the water surface increased with the concentration of Cl" increasing. The ability of counterion SO42- to improve FC16AB monolayer's compressibility is poorer than Cl-.With the technology of LB film, the monomolecular film of FC16AB wasdeposited on to quartz and CaF2 with hydrophilic surfaces on ultrapure water subphase, Y-type LB film of transfer ratio approaching to 1 is obtained. The LB film is demonstrated with UV-VIS, FT-IR spectra. The conclusions are as listed below:Compared with absorption of FC16AB in chloroformon, the absorption peak of FCifrAB in LB films shifted toward the shorter wavelength region, suggesting that some interaction among molecules due to the close molecular packing such as H-aggregates in the LB films. Comparing UV-vis spectra of FC16AB in LB films deposited from Cl- subphase with from aqueous subphase, this blue shift phenomenon of absorption demonstrated Cl- made the compactness of FC16AB LB films increasing. FT-IR spectra of FC16AB in LB films at different temperature showed that there is a gradual disordering of alkyl chain from 27癈 to 200癈, but no district phase transition appeared. This showed LB film of FC16AB has a poor thermal stability.By the technology of mixed monolayer, we studied bilirubin/cholesterol mixtures at the air/water interface. The ~A isotherms for bilirubin /cholesterol of different stoichiometry were measured and were dealt with by some mathematic methods. The conclusions are as listed below:It showed that the compressibility of the mixed monolayer could be increased by adding cholesterol into bilirubin monolayer, which was called condensing effect of cholesterol in the biological membrane. It showed that there was LE-C phase transition within pure bilirubin monolayer and LE-C phase transition gradually became weakened with XBR decreasing. The complexes of 3:2 stoichiometry between bilirubin and cholesterol can form in the mixing monolayer. But the complexes would be broken upon compression.We measured and analyzed the -A isotherms for pure bilirubin, pure cholesterol, bilirubin /cholesterol (XBR=60%) on the different pH subphase. The conclusions are as listed below:... |
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