Nonpolymeric compounds, compositions, and methods for forming microelectronic structures, and the structures formed therefrom are provided. The nonpolymeric compounds are ring-opened, epoxide-adamantane derivatives that comprise at least two epoxy moieties and at least one adamantyl group, along with at least one chemical modification group, such as a chromophore, bonded to a respective epoxy moiety. Anti-reflective and/or planarization compositions can be formed using these compounds and used in lithographic processes, including fabrication of microelectronic structures.