Four free-base corroles with electron-donating or electron-withdrawing groups on the para or 2 through 6-positons of the meso phenyl rings were prepared via either Paolesse or Gross conditions and investigated for their absorption and emission properties. The triaryl corroles 5,10,15-triphenylcorrole, 5,10,15-tris(pentafluorophenyl)corrole, 5,10,15-tris(p-nitrophenyl)corrole, and 5,10,15-tris(p-methoxyphenyl)corrole were examined. Absorption, steady-state, and time-resolved fluorescence measurements were performed on all compounds in both nonpolar (dichloromethane) and polar (dimethylacetamide) solvents. The experimental evidence points to hydrogen bonding with an internal N-H group as the most likely factor in the solvent-dependent photophysical behavior of these corroles, that is also highly dependent upon substitution.

Two high resolution single X-ray crystal structures of meso-substituted free-base corroles are presented: 5,10,15-triphenylcorrole (1) and 5,10,15-tris(pentafluorophenyl)corrole (2). The internal NH protons are clearly assignable to different nitrogens, which represents the two tautomer limits of corrole.

[reaction: see text] An improved methodology for the N-alkylation of the porphyrin isomer N-confused porphyrin is presented. The combination of polar solvent conditions and the use of the base Cs2CO3 affords externally modified products in high yield without separation difficulties and without the use of large excesses of alkylating reagent. The further transformation and metalation of these products provides opportunities for the construction of metalloenzyme model complexes, peptide adducts, and chromophore assemblies.

Porphyrin derivatives R 0130 Facile Peripheral Modification of N-Confused Porphyrin. -An improved method for alkylation of porphyrin isomer (I) is developed with a view to application of the products in metalloenzyme models, peptide adducts and chromophore assemblies. -(QU, W.; DING, T.; CETIN, A.; HARVEY, J. D.; TASCHNER*, M. J.; ZIEGLER, C. J.; J. Org. Chem. 71 (2006) 2, 811-814; Dep. Chem., Univ. Akron, Akron, OH 44325, USA; Eng.) -Nuesgen 21-120

In view of micro fuel cells, the silicon processes are employed for microfabrication of the micro direct methanol fuel cell (gDMFC). Using the MEMS technology we have successfully made single gDMFC as small as 8mmx8mmx3mm. The main reason for the use of MEMS processes is the prospective potential for miniaturization and economical mass production of small fuel cells. The double side deep wet etching for the gas channel and fuel chamber preparation and the formation of porous silicon (PS) layers for electrode supports by electrochemical process are the key technologies to improve the MEMS-based ,uDMFC. Moreover, for the first time, the fabrication of electro-catalytic electrodes using electroless plating platinum and ruthenium (PtRu) co-deposition method over porous silicon (PS) substrates is introduced. Then the electro-catalytic electrode was characterized using scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDX). Using the MEMS technology makes the batch fabrication of tDMFCs much easier and reduces the usage of rare metals.