Self-assembly of nanometre-scale metallacalix[4]arene building blocks and Keggin units to a novel (3,4)-connected 3D self-penetrating framework.

A novel (3,4)-connected 3D self-penetrating metal-organic framework with a nanometre-scale cavity constructed from metallacalix[4]arene building blocks and Keggin-type polyanions has been obtained by using a 1,3-bis(1-methyl-5-mercapto-1,2,3,4-tetrazole)propane ligand.