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Four organic dyes based on indolo[3,2,1-jk]carbazole (IC-1, IC-2, IC-3, and IC-4) with different π-bridges (benzene ring and thiophene ring) are used for dye-sensitized solar cells (DSSCs) to investigate the effect of π-bridge on their photovoltaic performance. The introduction of thiophene ring as π-bridge (the dye IC-2) greatly improves the cell performance compared to benzene ring. The increasing conjugation length of the molecules decreases the performance of DSSCs. The best performance of DSSC based on IC-2 is obtained with a Voc of 0.66 V and a conversion efficiency of 3.68%. The poor performance of DSSCs based on IC-1 and IC-3 which contains only benzene ring as the π-bridge can be attributed to poor spectral coverage and higher electron charge transfer resistance as evaluated from EIS studies.

Reaction of (S)-4-carbomethoxy-2-phenyl-2-oxazoline with Pd(OAc)2 leads to the formation of the ortho-palladated complex (S,S)-di-μ-(acetate)-bis{2-[2-(4-carbomethoxy)oxazolinyl]phenyl-C,N}dipalladium(II) (1). In the presence of water, this complex reacts with methylparathion to produce p-nitrophenol as well as two oxazoline palladium dimethylthiophosphate complexes (2 and 3), which have been observed in solution by 31P NMR. This reaction is accompanied by racemization of the oxazoline ligand and ultimately produces the dinuclear complex (R,S)-di-μ-(dimethylthiophosphate-S,S)-bis{2-[2-(4-carbomethoxy)oxazolinyl]phenyl-C,N}dipal-ladium(II) (4), which features bridging dimethylthiophosphate ligands. At pH 9−10, complex 1 serves as a precatalyst for the hydrolysis of methylparathion. The reaction rate has a first-order dependence in substrate and palladium catalyst with a second-order rate constant of 726 (± 30) M-1 s-1 at pH 9.0.