CdCu3(OH)6Cl2: A new layered hydroxide chloride

A new transition metal hydroxide chloride containing kagome layers of magnetic ions, CdCu3(OH)(6)Cl-2, has been synthesized and structurally characterized. The actual low symmetry P2(1)/n structure can be derived from the ideal trigonal one with a change in cation distribution and coherent distortions of the anion framework. The result is a fundamentally different Cu2+ kagome framework than found in the related Herbertsmithite and Kapellasite minerals. Magnetization measurements show no transition to long range magnetic order above T=2 K, despite strong antiferromagnetic interactions with a Weiss temperature of theta(w)= -150 K. Furthermore, we show that the structure of CdCu3(OH)(6)Cl-2 and related hydroxide chlorides can be rationalized on the basis of [(OH)(3)Cl](4-) pseudopolyatomic anions that pack and rotate, in much the same way as do traditional polyatomic anions. This opens the door to rational design of new and useful hydroxide chloride materials. (C) 2011 Elsevier Inc. All rights reserved.