Since the discovery of aggregation-induced emission phenomena (AIE) in 2001. new application posibilities of organic systems have been discovered in the development of optoelectronic devices, biological imaging, sensorics and many other research areas. Application of many organic molecules is restricted due to aggregation-caused quenching with bigger concentrations or in the solid state. Because of that AIE phenomena can be considered as the key that leads to many new applications. From that point of view, represented work is more about characterisation of novel Schiff bases that have a benzoimidazole core. The primary aim of this work is development of new AIE matherials and systems. Optical properties of novel Schiff bases were investigated to determine whether they show AIE phenomena or not. Besides that it was investigated whether these Schiff bases are applicable in optical sensing as fluorescent probes or as materials in optical sensors. Absorption and emission spectra of novel Schiff bases were recorded, as well series of titration spectra andsolid state emission spectra. Tyndall phenomena has been used to determine whether Schiff bases make nanoaggregates in aqueous solution. The sample was subjected to cycles consisted of grinding and exposure to the solution fumes in order to observe the sample's mechanochromic properties. Tests show that four benzoimidazole derivatives make aggregates in aqeous media: compound 3-2-[(4-N,N-diethylamino-2-hydroxy)benz-2-ylideneamino]-5(6)-nitrobenzimidazole, compound 15-2-[(4-N,N-dimethylamino)benz-2-ylideneamino]-5(6)-cyanobenzimidazole, compound 16-2-[(4-N,N-dimethylamino)benz-2-ylideneamino]-5(6)-methylbenzimidazole and compound 17-2-[(4-N,N-dimethylamino)benz-2-ylideneamino]-5(6)-nitrobenzimidazole. Those aggregates show very low emission intensities. and therefore we cannot describe the observed aggregates as typical AIE phenomena. However, it is found that AIE emission is responsible for intensive solid state emission (substances 3, 15, 16 i 17). Dust samples of 3 and 17 substances also showed mechanochromic properties. It is worth mentioning that compound 3 showsbetter photophysical properties than compound 17.