Preparation and Properties of Cyclophosphatophosphonates with 6-and Cyclophosphates with 6- to 20-Membered Ringanions

Pure cyclotri-, -hexa-, -octa- and decaphosphates are prepared by topochemical controlled thermal dehydration of certain dihydrogenphosphates. Cyclophosphatophosphonates are prepared by heating geminal diphosphonic acids and phosphoric acid in molten urea. Cyclophosphatanions larger than cyclopenta-phosphateare very resistant against hydrolysis. The complexing abilities of cyclophosphates increase with ring size. Phospatophosphonates are more resistant to ring cleavage than the correspondend cyclophosphates.