The calculated repeating unit with a length of about 2.0 nm was obtained. The obtained experimental value was in range of 2.0~2.1 nm, which was in good accordance with the calculation result. In addition, for the xerogels of TC14-Lu from DMF, with the decrement of alkyl substituent chains, the weaker intermolecular hydrophobic force between the alkyl chains of the neighboring molecules will not enable present gelators to orderly assemble as in the case of TC18-Lu and shows a shorter layer distance and more disorderly stacking unit. For the case of TC12-Lu, no gel can be prepared due to the shortest alkyl
substituent chains, as shown in Figure 9b. Meanwhile, it should be KU57788 noted that this phenomenon is similar to the results of recent reports [49, 50]. Therein, the substituent groups in azobenzene residue or benzimidazole/benzothiazole imide derivatives can have a profound effect upon the gelation abilities and the as-formed nanostructures of the studied compounds. For the
present system, the experimental results demonstrated again that the alkyl substituent chains had played a very important role in regulating the assembly modes and nanostructures in these organogels. Now the ECL properties generated by the present xerogels of these luminol derivatives in the presence of hydrogen peroxide are under investigation to display the relationship between the molecular structures, as-formed nanostructures, and ECL sensors. Figure 9 Schematic pictures of assembly modes. (a) TC18-Lu in organogels and (b) TC12-Lu MAPK inhibitor in solution. Conclusions Some luminol imide derivatives with different alkyl
substituent chains have been synthesized. Their gelation behaviors in various organic solvents can be regulated by changing the length O-methylated flavonoid and number of alkyl substituent chains. The experimental data demonstrated that the length of alkyl substituent chains linked to a benzene ring in these imide derivatives can have a profound effect upon the gelation abilities of these studied compounds. Longer alkyl chains in molecular skeletons in the present gelators are favorable for the gelation of organic solvents. Morphological studies revealed that the gelator molecules self-assemble into different aggregates from dot, flower, belt, rod, and lamella, to wrinkle with change of solvents. Spectral studies indicated that there existed different H-bond formations and hydrophobic force, depending on the alkyl substituent chains in molecular skeletons. The present research work affords a new useful exploration for the design and development of new versatile low molecular mass organogelators and soft matter for ECL biosensors with luminol functional groups. Authors’ information TJ and QZ are associate professors. QH is an MD student. DX is a professor. FG is a professor and the dean of the School of Environmental and Chemical Engineering. JZ is a laboratory assistant in Yanshan University.