Two unprecedented nickel–boron cluster-containing POMs have been isolated through a facile approach by the reactions of trivacant [A-α-SiW9O34]10− and Ni2+ in borate buffer. The {BO3} and {B2O4(OH)2} units enclosed in the Ni8 cluster of 1 and the Ni12 cluster of 2 play important templating roles in the assembly of the target compounds.
