Anisotropic visible and infrared(IR).absorption spectra of Langmuir-Blodgett(LB).films of mutually mixed merocyanine dyes deposited with Cd2+ ions were recorded. In these films, a merocyanine dye ‘DO’ is included in J-aggregates, although in LB films of DO(not mixed with other merocyanine dyes), DO itself does not form J-aggregates. A difference spectrum method successfully separated the spectra observed into two components, one of which was due to J-aggregates. This component includes the contribution of the J-aggregated DO molecules and compared well with the absorption spectra observed for LB films of DO. This comparison detected, for the aggregated DO, red shifts of several IR bands due to softening of the bond alternation in the central conjugated system of the molecule, which thus suggested that intramolecular charge transfer is enhanced by the formation of J-aggregates.

Novel smart materials can be synthesized and designed at the molecular level by attaching well characterized and tailored functionalities to be used in in vitro and in vivo oximetry. A series of porphyrins and metalloporphyrins were synthesized and their EPR and UV-vis spectra studied. The steric hindrance and electronic effects of the substituted groups and the characteristics of different metal ions were the major contributors in influencing the properties of the compounds. As a result, their EPR and UV-vis spectra changed. Through studying the EPR spectroscopic properties of these compounds, we hope that novel EPR oximetry materials can be found and this will help to extend the applications of EPR oximetry in vivo.

Low molecular weight nitroxides are widely used as electron paramagentic resonance(EPR)-detectable spin labels in the biological and pathological areas. A novel nitroxide derivative, 4-ferrocenecarboxyl-2,2,6,6-tetramethyl piperidine-1-oxyl(FC-TEMPO), was synthesized for evaluating the effects of spin label compounds on tumor cells and firstly its biological effects on tumor and normal cells were evaluated. The cytotoxicity of FC-TEMPO in the hige metastatic lung carcinoma cells(95-D) showed that it markedly inhibited the viabillity of cancer cells in a dose-dependent manner, while it was less toxic to a normal human cell line. Further studies found that FC-TEMPO suppressed the growth of tumor cells by induced apoptosis through activating caspase-3 but not caspase-8 which was proved by caspase inhibitors, and the cell cycle arrest at G; phase. Moreover, the concomitant increase of superoxide dismutase(SOD) and catalase (CAT) activity was boserved. Taken together, these resluts right provide a base for further anticancer investigations of nitroxides and their potential pharmacologicalapplications

The xerographic properties of dual-layer photoreceptors having different molecular structure, are described with respect to their photosensitivities. A correlation between the absorption wavelength and the photosensitivity was found. A study on device optimization of 3,4,9,10-perylenetetracarboxylic diimides was carried out. The dual-layer photoreceptor device exhibited low dark decay and flat spectral response from 450-750 nm. The spectral sensitivity of the dual-layer photoreceptor extends to the near-IR region.

LB films of organic-inorganic charge-transfer systems, Cu-complexes of 2-methyl-5-octadecyIDCNQI(C18MeDCNQI) and 2-alkylTCNQ(CnTCNQ with n=12,15 and 18), were successfully fabricated by utillizing the airwater interface as a reaction field for the reduction of the acceptor moieties. The charge transfer degrees of the C18MeDCNQI and CnTCNQ in the LB films were estimated at -1, respectively, from the changes in their IR absorption spectra upon the reduction. The molecular orientation in the films were discussed on the basis of polarized IR spectroscopy. It is suggested that the molecular orientation in the present LB films is largely affected by the coordinate bonds between the Cu cations and the cyanic groups.