A new compound in kidney stones? Powder X-ray diffraction study ofă calcium glycinate trihydrate
Résumé
The present identification of a new compound in kidney stones is relevant in clinical practice. Here, poly[[di-[mu]-aqua-bis(glycinato-[kappa]2N,O)calcium(II)] monohydrate], {[Ca(C2H4NO2)2(H2O)2]·H2O}n, has been identified in a possible kidney concretion, although it could be a `false calculus' associated with Munchausen syndrome. The crystal packing is characterized by an infinite zigzag chain of Ca atoms in [Ca(OW)4O2N2] (OW is a water O atom) square antiprisms, sharing edges formed by water molecules. An uncoordinated water molecule interconnects the parallel chains in a three-dimensional hydrogen-bonding scheme. Similarities between the trihydrate and the monohydrate are described.