A new polymorph of lithium tetrabenzoporphyrin radical

Abstract A new polymorph of lithium tetrabenzoporphyrin Li(tbp) radical was discovered. When the film fabrication of Li(tbp) was performed by the vacuum deposition technique using reported x-Li(tbp), the obtained film retained the x-form molecular arrangement. However, by immersing in acetone or vacuum sublimation, x-Li(tbp) could be transformed into a distinct polymorph, which we designate as the α-form, that is isomorphous to ordinary M(tbp), such as Cu(tbp) and H2(tbp). The compressed pellet of α-Li(tbp) showed semiconducting behavior, whose electrical resistivity at 298 K of 103 Ω cm is as low as that of x-Li(tbp), suggesting the potential utility of α-Li(tbp) as an electronic and/or magnetic material.