Photophysical and Electrochemical Properties of Newly Synthesized Stilbazolium Dyes

Abstract

In this study, the spectral and electrochemical properties of three newly synthesized stilbazolium dyes possessing an enlarged π-conjugated system were examined. The synthesis of the dyes was carried by Knoevenagel condensation of 1-butyl-4-methylquinolinium bromide as a common acceptor moiety precursor and different donor moiety precursors (2-hydroxynaphtaldehyde or 4-hydroxy-naphtaldehyde or 4-N, N-dimethylamino naphthaldehyde). The composition of the produced compounds was confirmed by 1 H-and 13 C nuclear magnetic resonance (NMR) spectroscopy, elemental analysis, and infrared (IR)-spectroscopy. Their properties including the solvatochrom-ism in different solvents were investigated by ultraviolet-visible (UV-Vis) and fluorescence spectroscopy. The electrochemical properties of the dyes' solutions in methanol were explored by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The optical band-gap values as well as the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the dyes were estimated based on experimental data and compared. A putative mechanism of electrochemical oxidation/reduction of the investigated dyes was also proposed.

Wolffia globosa as a biocatalyst in plant-based biofuel cells

“…This mediated electron transfer mechanism is in good agreement with previously proven EnMs for both aquatic plants [5,6] and yeast cells [15,16]. However, so far only a few EnMs have been identified from bacteria, which is the reason why they are collectively called "endogenous mediators" [17]. While Shewanella oneidensis secretes flavin molecules, Pseudomonas aeruginosa self-produces nitrogen-containing heterocyclic phenazine metabolites such as pyocyanin [18].…”