In recent years, organic materials have attracted much attention for potential use in a variety of optic, electronic and optoelectronic applications. Generally, target functionalities and the performance of devices created with such organic compounds strongly depend on the order of the active species over a range of length scales. Since their discovery, materials based on organic π-conjugated molecules have good properties such as thermal and photochemical stability ad high charge mobility, which make them promising candidates for research on optoelectronic device technology, such as LEDS, Transistors (TFTs) and low-cost solar cells. In this work a quantum chemical investigation has been performed to explore the optical and electronic properties of a series of different compounds based on. 20 imidazo[4,5-b]pyridine derivatives. Different electron side groups were introduced to investigate their effects on the electronic structure. The theoretical knowledge of the HOMO and LUMO energy levels of the components is basic in studying organic solar cells so the HOMO, LUMO and energy Gap of the studied compounds have been calculated and reported. These properties suggest these materials as good candidates for organic solar cells.