Radicals, which possess unpaired electrons, play a vital role in organic chemistry, structural chemistry, and functional material chemistry. Nowadays, their research becomes ubiquitous and interdisciplinary spanning physics and biomedical fields. For instance, the oxygen we breathe in the air, the first organic superconducting material, tetrathiafurane (TTF) cation，and the nitric oxide which regulates the function of blood vessels (the related work was awarded the Nobel Prize in Physiology and Medicine in 1998), are all radicals. Radicals are usually active and possess short lifetime because of the presence of the unpaired electrons. Therefore, the stabilization of active radicals is a pivotal research challenge in this field, as well as a hot study topic in contemporary scientific world.