Maciej Chotkowski

Extension of Pyrrolopyrrole π-System: Approach to Constructing Hexacyclic Nitrogen-Containing Aromatic Systems

A facile three-step approach to synthesizing quinoline-fused pyrrolopyrroles is reported. The crucial step in this synthesis is the condensation of 2-aminophenyl substituted pyrrolopyrroles with aromatic aldehydes. The resulting hexacyclic ladder-type dyes strongly absorb UV radiation and exhibit fluorescence at 450-510 nm. The presence of pyridine-type and pyrrole-type nitrogen atoms is important for the electronic properties of this almost planar heterocycle. These heteroatoms, along with the addition of moderate electron-withdrawing and electron-accepting substituents, provide a means for fine-tuning of the emission characteristics of the polycyclic conjugates.

CHARACTERIZATION OF Pt–Rh–Ru CATALYSTS FOR METHANOL OXIDATION

Pt–Rh–Ru alloy catalysts for methanol electro-oxidation were prepared by electrochemical deposition under constant potential conditions. The Pt:Rh:Ru ratio was varied by changing electroplating solution composition. Obtained catalysts were examined electrochemically in acidic solutions containing methanol. Stripping voltammetry was applied to study adsorption of methanol on the electrodes surfaces while oxidation of methanol from solution was studied by means of chronoamperometry and cyclic voltammetry. The highest electrocatalytic activity was observed for an alloy with the highest obtained ruthenium concentration of 31%.