Unusual supramolecularly assembled hexadecameric water cluster in complex of Co(II)

An unusual (H2O)16 cluster in a compound of {[Co(C7H3N2O6)2(H2O)4] · 4H2O}2 1 (where C7H3N2O6 = 3,5-dinitrobenzoic acid (DNB)) has been synthesized and characterized by single-crystal X-ray diffraction, thermogravimetry, infrared spectra, and elemental analysis. The (H2O)16 cluster consists of a decameric water cluster and six water molecules, and plays an important role in stabilizing the structure in 1. We believe that the water structure demonstrated herein brings to light yet another novel mode of the cooperative association of the water molecules, and this discovery is helpful in improving the modeling of some of the unexplained properties of water, and understanding better the structure and behavior of hexadecameric water cluster.