Ligand-Directed Template Assembly for the Construction of Gigantic Molybdenum Blue Wheels.

Template-mediated synthesis is a powerful approach to build a variety of functional materials and complex supramolecular systems. However, the systematic study of how templates structurally evolve from basic building blocks, and then affect the templated self-assembly, is critical to understanding and utilizing the underlying mechanism, to work towards designed assembly. Here we describe the templated self-assembly of a series of gigantic Mo Blue (MB) clusters 1-4 using l-ornithine as a structure-directing ligand. We show that by using l-ornithine as a structure director, we can form new template⊂host assemblies. Based on the structural relationship between encapsulated templates of {Mo8 } (1), {Mo17 } (2) and {Mo36 } (4), a pathway of the structural evolution of templates is proposed. This provides insight into how gigantic Mo Blue cluster rings form and could lead to full control over the designed assembly of gigantic Mo-blue rings.