Channel-containing lanthanide mucate structures

Abstract

The structure determination of M₂muc₃·8H₂O (M = La, Ce, Pr, Nd; muc = mucate, [OOC(CHOH)₄COO]^2-) shows an open 3D network with hexagonal channels running parallel to the unique direction. A second crystalline form of hydrated Nd₂muc₃ is obtained, which is shown to be a 2D polymer with the (6,3) topology and with a geometry resembling brickwork. In this structure, sheets of Nd₂muc₃(H₂O)₄ are cemented to neighbours by an extensive hydrogen bonding system so as to generate parallel channels of almost square cross-section running normal to the sheets. Crystals of Eu₂muc₃(H₂O)₄·10H₂O are isostructural with the orthorhombic form of Nd₂muc₃(H₂O)₄·10H₂O.