Electronic and Magnetic Properties of Free Radical Crystals

理解具有奇数电子的稳定自由基（FRAC）中的强相关效应，原则上可以使我们能够设计所有的“塑料”电子材料，例如。只含有s和p元素的材料，这使得制造一系列有机半导体，磁体，甚至金属成为可能。在这种范式转变中，我们将不再从原子中构建电子，而是从化学复杂的分子中构建电子，这有可能导致分子电子时代的到来。由于比填充的惰性气体配置（具有偶数个电子）所需的电子少一个电子，使得自由基具有高度的化学反应性。尽管如此，化学家们已经发现了使它们稳定的方法：加入芳环，使未成对电子离域，或者引入大的取代基作为侧基。

Understanding the strong correlation effects in stable free radicals (FRACs) with an odd number of electrons could in principle enable us to engineer all ``plastic'' electronic materials, eg. materials containing only s and p elements, which could make it then possible to fabricate a whole range of organic semiconductors, magnets, and maybe even metals. In this paradigm shift, instead of building electronics from atoms, we would be building them from chemically complex molecules, which has the potential to give rise to the age of molecular electronics. Being one electron short of what is required for a filled noble gas configuration, which have an even number of electrons, makes the free radicals chemically highly reactive. Nevertheless, chemists have discovered ways how render them stable: the addition of aromatic rings, delocalization of the unpaired electron, or the introduction of bulky substituents as side-groups.