A new approach to coordination chemistry involving phosphorus-selenium based ligands. Ring opening, deselenation and phosphorus-phosphorus coupling of Woollins' Reagent

► [CpCr(CO)3]2 (1) undergoes facile reaction with an equivalent of Woollins' Reagent at ambient temperature. ► The ring-opening reaction of Woollins' Reagent was initiated via homolytic P-Se bond cleavage by CpCr(CO)n· (n = 2 (2A) or 3 (1A)). ► The ease of fragmentation of the P-Se heterocyclic ligand which leads to ring opening in Woollins' Reagent resembles well with its P-S analogue, Lawesson's Reagent.