10,10'-(m- and p-phenylene)diphenothiazine Dicationjs: Violation of a Topology Rule in Heterocyclic High-Spin pi-Systems

摘要

In the field of organic-based magnets and ferromagnetic materials, high-spin organic molecules have recently received intense attention. It is well-known that in Hydrocarbon high-spin molecules m-xylylene type hydrocarbons (non-Kekule hydrocarbons) are triplet species, whereas p-xylylene type hydrocarbons. (Kekule hydrocarbons) tend to be in quinoid form with singlet ground states. This topology rule has been supported by several theories and many experiments demon-strafing high-spin ground states innon-Kekule hydrocarbons, although exceptions, i.e., singlet ground states in non-Kekule systems, have recently been reported. In addition to this topological strategy, a different method toward high-spin states by orthogonal alignment of the spin-canying pi-systems has also been studied. Although this approach certainly allows the detection of higher spin states, the ground states so far observed are of lower spin multiplicity.