Two polyoxovanadoborates with over 100 nuclei assembled from a {V14Co12B72} cluster

Combining theoretical prediction and experimental exploration, the first sandwich-type polyoxovanadoborate (POVB) with an odd number of nuclei, [V 11 B 26 O 73 (OH) 10 ] 8− (1), was discovered under hydrothermal conditions. Density-functional theory (DFT) gives a rationalization for the existence of this structure and the structural feature is consistent with the {V N B 2N+X } (X = 2, 4, 6, 8) general formula. Excitingly, when Co and 1,10-phenanthroline (phen) are introduced into the synthesis of vanadoborates system, a 100-nuclei [Co 6 (phen) 10 (H 2 O) 8 ][V 14 Co 12 B 72 O 144 (OH) 20 ]·28H 2 O (2) and a 102-nuclei [Co 6 (phen) 14 (H 2 O) 4 ][V 14 Co 12 B 72 O 144 (OH) 20 ]·23H 2 O (3) with the same core structure of [V 14 Co 12 B 72 ] 12− are obtained. The vase-shaped [V 14 Co 12 B 72 ] polyanion is a multilayered sandwich-type structure containing seven distinct structural layers and is the largest known POVB. Furthermore, 2 demonstrates exceptional thermal and chemical stability and serves as an efficient and stable catalyst for the photoreduction of carbon dioxide.