Synthesis and Properties of New Cationic Nitrogen Radical Containing Compounds

概要

1.1 Radical chemistry
Radical, precisely a free radical with chemical definition, is an atom, molecule, or ion that
has unpaired valence electron or an open electron shell. In other words, it is an electrondeficient chemical species with a partially filled orbital. Owing to these unpaired electrons,
radicals features high reactivity and short lifetime and generally as a transient or intermediate
stage in many chemical reactions. Radicals and radical reactions are ubiquitous in our daily
life, they play important role not only in many chemical processes, such as atmospheric
chemistry, combustion, polymerization, plasma chemistry, biochemistry but also in living
organisms, such as superoxide and nitric oxide as well as their reaction products control and
regulate many biological activities and metabolism.[1]
In order to study the detailed chemical mechanism and radical reactivity, more and more
chemists devoted continuing efforts to observe and capture long-lived, stable radicals for over
a century. The first identified organic free radical was triphenylmethyl radical, which was
discovered by Moses Gomberg[2] in 1900 and unveiled the mystery of free radicals. After that,
a lot of researches focusing on observation and isolation of different radical species were
reported. Here are some examples of stable carbon, nitrogen, oxygen and sulfur-based organic
radicals showed in Figure 1.1.[2-3] Isolating the stable organic radicals attracts considerable
attention and as a research challenge due to these stable radicals have the potential applications
on spin trapping,[4] EPR imaging,[5] spin labelling,[6]as reporter molecules and on ferromagnetic
materials as building blocks. ...

この論文で使われている画像