A novel nonanuclear hafnium oxide-hydroxide-sulphate cluster crystallised from aqueous solution

Single crystals of (NH4)(14)[Hf9O8(OH)(6)(SO4)(14)]center dot nH(2)O (1) were obtained by heating a sealed aqueous solution of HfOCl2 center dot 8H(2)O, (NH4)(2)SO4 and H2SO4 at 80 degrees C for 10 days. The discrete [Hf9O8(OH)(6)(SO4)(14)](14-) anionic clusters have no inter-cluster connectivity. This rare nonameric architecture has only been observed previously in two Bi3+ oxo clusters.