Synthesis of Tetrazinyl Biradicals Containing 1,1′-Biphenyl Fragment

Abstract

4,4′-([1,1′-Biphenyl]-4,4′-diyl)bis(6-aryl-2-phenyl-5,6-dihydro-1,2,4,5-tetrazin-1-2H-yls) were obtained from bis(triflates) 1,1′-([1,1′-biphenyl]-4,4′-diyl)bis(3-aryl-5-phenyl-5,6-dihydro-1, 2,4,5-tetrazinium-1) synthesized from the corresponding 1,1′-([1,1′-biphenyl]diyl-4,4′)bis(3-aryl-5-phenylformazane). It was found that binuclear tetrazinium salts are formed by the action of formaldehyde and CF3SO3H on formazans, while mononuclear salts are formed by the action of HClO4. Tetrazinyl diradicals were isolated in the individual state and characterized by elemental analysis, IR and ESR spectroscopy.