Much effort has been devoted to the work of graphene-modification,as graphene and its derivatives possess potential applications in physics,chemistry and material science.Through density functional theory and CASSCF calculations,we have done some work to modify graphene patches as well as its derivatives,and obtained some meaningful achievements.Multi-Zn-expanded oligoacenes from benzene to pentacene are computationally proved to be open-shell broken-symmetry(BS)singlet diradicals with antiferromagnetic character,in contrast with the common fact that their parent oligoacenes are closed-shell systems and only acenes larger than octacene have open-shell BS singlet diradical ground states.Our designed multi-Zn-expanded graphene patches of nnn series are also BS singlet diradicals,but those of n(n+1)n series possess quintet tetraradical as their ground state and become open-shell BS singlet tetraradicals when they are in a higher energy state.For oligoacene dioxides,the simplest graphene oxides,they exhibit different ground states according to the position of two carbonyl groups: triplet ground states with a certain degree of ferromagnetic character for the middle insertion series,while open-shell BS singlet diradical ground states with strong antiferromagnetic character for both the single-side and the double-side expansion series.In all,the field of functional modification of graphene patches and its derivatives is booming,and we believe their applications will be realized in the near future.