The unique properties and perfect structures of fullerenes and carbon nanotubes (CNTs) predetermine their great influence on nanotechnologies. These nanoclusters demonstrate exceptional mechanical, physical, chemical, electronic and optical properties and have attracted enormous attention from researchers around the world [1-7]. Graphene, a planar sheet of sp2-bonded carbon atoms, is the fundamental component of graphite and carbon nanotubes. The discovery by Geim and Novoselov in 2004 [8] generated intense activity in graphene research. The sophisticated low-dimensional characteristics and outstanding mechanical properties have given rise to numerous technological applications of pristine graphene in various fields. Its use in electronic and optical devices, energy storage systems and composite materials, chemical sensors and drug delivery has been suggested [9–16]. Soon after, the chemical functionalization of graphene became a focus of modern physics and chemistry [11]. The main motivations for these experimental and theoretical studies were the modification of electronic properties via modification of the bandgap, the potential use of functionalized graphene for hydrogen storage, the search for techniques to massively produce "cheap" graphene » by chemical reduction of graphene oxide, oxidation and subsequent decompression. graphene as a method to create graphene nanostructures of a given size [17-20] . However, the reactivity of graphene as a planar sheet is much worse than that of CNTs and fullerenes. Therefore, only a few functionalization techniques have been transferred from fullerene chemistry to graphene chemistry, such as azo, aryne and nitrene additions [21–23], Claisen rearrangement [24], 1,3-dipolar cycloadditions and Diels–Alder [25, 26].Carbenes (CR2, R = H, ...... middle of article ...... the structural changes of graphene remain to be considered affected by dichlorocarbene The influence of the position of attached carbene species on the structure of graphene is also an important question. Furthermore, to the best of our knowledge, no attempt has been made by researchers to determine what influence solvents have. have on the binding energy of carbenes as well as on the band gap of functionalized graphene As described in the previous paragraphs, the functionalization of nanotubes and fullerenes with carbenes has been important given the importance that graphene reveals. Nowadays, we report here a comprehensive density functional theory study on CCl2 functionalization of finite-sized graphene sheets, focusing on the equilibrium structures of CCl2. -attached graphene and effects of attached dichlorocarbene on the electronic properties of graphene.