title: 4-[2-(Hydrogen phosphonato)-2-hydroxy-2-phosphonoethyl]pyridinium.
abstract: The title compound, C(7)H(11)NO(7)P(2), exists as a zwitterion in which the positive charge resides on the protonated pyridyl N atom and the negative charge on one of the two phosphate groups. In the crystal, adjacent molcules are linked by O-H⋯O and N-H⋯O hydrogen bonds into a three-dimensional network.
authors.forename: Feng-Lei
authors.initials: FL
authors.lastname: Wang
authors.forename: Rong-Xin
authors.initials: RX
authors.lastname: Yuan
authors.forename: Ji-Min
authors.initials: JM
authors.lastname: Xie