The crystal structure of trisodium nitriloacetate monohydrate

Abstract

The structure of trisodium nitriloacetate monohydrate, a powerful chelating agent, has been determined by X-ray single-crystal diffraction methods. The crystals are monoclinic, space-group P2₁/c with a= 8·547, b= 12·235, c= 10·446 Å, β= 110° 10′. The structure, which was determined by direct methods, contains intersecting layers of sodium ions forming channels parallel to [b] and in these channels are the nitriloacetate anions which are linked together, along [b], by hydrogen bonds to the water of solvation. The 6-fold co-ordination polyhedra around the sodium ions are distorted from octahedral symmetry by ring formation. The smallest of these rings contains only four members and subtends an angle of 53·1° at the sodium atom.