A mixed arsenic-phosphorus centered biradicaloid.

Main-group singlet biradicaloids have been thoroughly investigated in the past two decades, especially derivatives of cyclobutane-1,3-diyl. However, in each of the known examples, the radical centers are identical. Therefore, we sought to prepare a mixed dipnictadiazanediyls with P and As bearing the radical character. To achieve this goal, the unprecedented cyclodichloro arsaphosphadiazane [ClP(μ-NTer)2AsCl] had to be prepared first. Treatment of [ClP(μ-NTer)2AsCl] with a halide-abstracting agent led to the novel cyclic cation [P(μ-NTer)2AsCl](+), while reduction with magnesium afforded the first arsaphosphadiazanediyl [P(μ-NTer)2As].