GRAPHICAL ABSTRACT
Abstract
Sulfurization reaction of a stable 4,5,6-triphospha[3]radialene led to the formation of the corresponding methylene(thioxo)phosphorane, which was isolated and characterized. The characteristic absorption maximum of the sulfurized compound in electronic spectrum was shifted toward the longer wavelength region relative to that of the triphospha[3]radialene. Desulfurization reaction of the sulfurized compound to 4,5,6-triphospha[3]radialene was also demonstrated.