Head-to-head dimers in the zwitterion of 1-hydroxy-3-(pyrrolidin-1-yl)propylidene-1,1-bisphosphonic acid (EB 1053).
The title compound, 1-hydroxy-1-phosphono-3-(1-pyrrolidinio)propylidene-1-phosphonate, C(7)H(17)NO(7)P(2), is a member of the bisphosphonate class of drugs. As a zwitterion, it possesses a negative charge on one of the PO(3) groups and a positive charge on the pyrrolidine N atom. A zwitterion makes a contact with a neighbouring ion through the hydroxyl O atom and two phosphonyl O atoms, one each from two different PO(3) groups. Hydrogen bonding involves O-H.O and N-H.O interactions; the former are involved in the formation of head-to-head dimers, while the latter join the dimers into a chain running along the crystallographic b axis.
Escuela de Ciencia y Tecnología, Universidad Nacional de General San Martín, Calle 91 3391, 1653 Villa Ballester, Buenos Aires, Argentina. fernande@tandar.cnea.gov.ar
Daniel
D
Fernández
Daniel
D
Vega