1,3,3,3′,3′-Pentaisopropyl-1,3,3′,6,6′,7,7′-heptahydro-1λ5-1,1′-spirobi[acenaphtho 5,6-cd][1,2,6]oxadiphosphinine]-3,3′-diium Triiodide

Reaction of bis(peri-substituted) triphosphine iPrP(AcenapPiPr2)2 (Acenap = acenaphthene-5,6-diyl) with iodine, followed by hydrolysis, afforded ionic species with [iPrP(AcenapP(O)iPr2)2] dication, containing P-O-P-O-P motif, balanced by triiodide anions. The new species were fully characterised, including single crystal X-ray diffraction. The formation of the unusual double-bridged motif is likely a result of crowding in the peri-region.