title: Crystal structure of poly[[di-μ2-aqua-aqua-sodium] 4-amino-3,5,6-tri-chloro-pyridine-2-carboxyl-ate trihydrate], the sodium salt of the herbicide picloram.
abstract: In the structure of the title complex, {[Na(H2O)3](C6H2Cl3N2O2)·3H2O} n , the sodium salt of the herbicide picloram, the cation adopts a polymeric chain structure, based on μ2-aqua-bridged NaO5 trigonal-bipyramidal complex units which have, in addition, a singly bonded water mol-ecule. Each of the bridges within the chain, which extends parallel to the a axis, is centrosymmetric, with Na⋯Na separations of 3.4807 (16) and 3.5109 (16) Å. In the crystal, there are three water mol-ecules of solvation and these, as well as the coordinating water mol-ecules and the amino group of the 4-amino-3,5,6-tri-chloro-picolinate anion, are involved in extensive inter-species hydrogen-bonding inter-actions with carboxyl and water O atoms, as well as the pyridine N atom. Among these associations is a centrosymmetric cyclic tetra-water R 4 (4)(8) motif, resulting in an overall three-dimensional structure.
authors.affiliation: Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
authors.forename: Graham
authors.initials: G
authors.lastname: Smith
keywords: Tordon; coordination polymer; crystal structure; herbicide; hydrogen bonding; picloram; sodium salt; sodium–water cationic chain