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

A new transition metal hydroxide chloride containing kagomé layers of magnetic ions, CdCu3(OH)6Cl2, has been synthesized and structurally characterized. The actual low symmetry P21/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+ kagomé 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 θw=−150 K. Furthermore, we show that the structure of CdCu3(OH)6Cl2 and related hydroxide chlorides can be rationalized on the basis of [(OH)3Cl]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.