Propane-2,2-diphosphonic acid

The crystal structures of glycylaminomethylphosphonic acid, and of methane-, ethane-, and propane-diphosphonic acids, have been determined. The unit cell of the last acid contains two molecules, with different conformations. The molecular structures of the constrained phosphite (161), the phosphate (162), and the thio-phosphate (163) have been compared. The nitrogen in the last compound is very nearly trigonal planar, and the large P—N distance (313 pm) shows that there is little P - - N interaction. The phosphazene (164) adopts a novel conformation, ... 

Block, H.D., and Kallfass, H., Substituted propane-1,3-diphosphonic acids and -phosphinic acids, Bayer A.-G., German Patent Appl. DE 2621604, 1977 Chem. Abstr, 88, 89844, 1978. 

Chemical name 3,3-Diphosphono-1,2-propane-dicarboxy acid, tetrasodium salt (DPD) 1,2-dicarboxypropane diphosphonate Chemical structure OHO II 1 II HO — P — C — P — OH 1 1 1 HO OH CHCOOH 1 CH COOH Dicarboxypropane diphosphonic acid... 

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