3,5-Di--butyl-3'-(--butyl--aminoxy)-4-oxybiphenyl: A Heterospin Diradical with Temperature Dependent Behavior.

The title diradical was synthesized and investigated by ESR and UV-vis spectroscopy. It was found to have a lifetime of weeks even in the presence of oxygen, and even survives brief heating in toluene up to about 60 °C. In the UV-vis spectrum, the diradical showed reversible thermochromic behavior in the -10 to 50 °C range.