A Solid-State/Phonor Engineering Approach to Organic Superconductors

Molecular self-assembly is a powerful tool for the control of solid-state order. Application ofthis method to the modification of electronic properties in acenes has produced compounds with dramatically enhanced conductivities, coupled with improved oxidative stability. This proposal addresses the modification of acenes to enhance electron-phonon interactions, particularly with respect to the control of lattice vibrations and close intermolecular contacts. Facets of the two dominant paradigms in organic superconductivity, namely the cha1cogen-rich charge transfer complexes based on TTF and the electronically-doped hydrocarbons, will be combined with our crystal engineering approach to lead to entirely new candidates for superconductivity studies. For example, through careful manipulation of acene functionality, the density of electroactive acene moiety in the solid can be reduced, potentially leading to superconductivity in the electronically-doped state. Other chalcogen-rich acene derivatives with carefully engineered solid states will be electronically doped to determine whether these heavy atoms have a beneficial effect on the critical temperature. A more precise understanding of phonon modes in organic solids will come from a detailed structure-property relationship study of a myriad of acene derivatives with known solid-state order. Further engineering these solids to diminish electron-phonon coupling may lead to a new class of thermoelectric materials for solid-state cooling and energy generation applications.