초록 |
We have fabricated dicyanopyrazine-linked porphyrin mono and multilayer films on polycrystalline gold and quartz substrates using the Langmuir-Blodgett (LB) technique. Two different porphyrins were studied, one with two and the other with four positions of the porphyrin ring substituted with the dicyanopyrazine containing moiety (designated 2-DCPP and 4-DCPP, respectively). XPS indicates that the atomic ratios of C, N, and O for the LB films are similar to the theoretical ratios for the dicyanopyrazine-linked porphyrins. AFM reveals that the surface roughness of LB multilayers are higher than that of the LB monolayers due to aggregation of the porphyrin molecules in the multilayer films. The 11-multilayer LB films are only 6 and 4.6 times thicker than the monolayer LB films. This result is consistent with the surface roughness data showing aggregation of dicyanopyrazine-linked porphyrin in multilayer LB films. UV-vis spectroscopy indicates a blue shift of the Q band of the LB films compared with the dicyanopyrazine-linked porphyrin solution due to interaction between stacked porphyrin rings. |