Construction of Local Spin Ordering System through Polarons

点击翻译按钮获取中文摘要

Construction of high spin molecules is an important target of research in molecular magnetism'. We have demonstrated a number of high spin polycarbenes based on the pi-topology. However there is a problem concerning the kinetic stability of high spin polycarbenes. The aim of this project is to prepare stable high spin molecules, replacing a siguma-spin and a pi-spin of carbenes with a local spin of the stable radical unit and a polaronic spin in the conjugated pi-system. As a target molecule we designed a polypyrrole carrying nitronyl nitroxide groups. A ferromagnetic coupling of the oligomers is originated from a space-sharing nature of the partial molecular orbitals belonging to the radical unit and the pyrrole unit. As an appropriate building block of such a high spin oligopyrrole, we prepared several pyrrole derivatives and found that N-(p-NN-phenyl)pyrrole affords a ground state triplet species upon one-electron oxidation. Furthermore, thienyl groups were introduced at the alpha-positions on both sides of the pyrrole ring as reactive sites. This monomer turned out to afford desired hybrid-oligomers under the oxidative condition. Magnetic and conductive properties of them will be investigated even after the research period of this project.