THE MOLECULAR-STRUCTURE OF 4-AMINO 1-HYDROXY BUTYLIDENE-1 BISPHOSPHONIC ACID (AHBBPA) - AN UNCOMMON ANHYDROUS HYDROXYBISPHOSPHONIC ACID

The molecular structure of an anhydrous hydroxybisphosphonic acid was determined by X-ray diffraction techniques and compared to the corresp onding hydrated crystalline form. The hydrogen bond network and interm olecular interactions show that the polar bisphosphonic group undergoe s a rotation to accomodate a different distribution in the hydrophobic /polar zones observed in the crystal packing, while the rest of the am ino side chain connected to the functional carbon atom has identical c onformation.