The preparation of yl-2,8-dioxa-1-phosphabicyclo[3.3.0]octa-3,6-diene
(Dit-BuADPO . F2) from hexafluoropropylene oxide (HFPO) and ,8-dioxa-1
-phosphabicyclo-[3.3.0]octa-2,4,6-triene (DitBuADPO) is described. The
solid state structure of DitBuADPO . F2 shows an unusual square pyram
idal geometry. The structural and spectroscopic properties of DitBuADP
O . F2 are compared with other oxidized derivatives of DitBuADPO that
contain 5-coordinate phosphorus.