Control over coordination self-assembly of flexible, multidentate ligands by stepwise metal coordination of isopyrazole subunits.


Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8 Kita-ku, Sapporo, Hokkaido 060-8628, Japan. [Email]


Structurally flexible oligoisopyrazole molecules were self-assembled into discrete complexes with structural diversity upon palladium coordination. Structural convergence was controlled by a stoichiometry change to induce stepwise metal coordination of isopyrazole subunits. Three different types of complexes were selectively generated from a diisopyrazole ligand. Furthermore, tetraisopyrazole ligands were quantitatively assembled into a discrete complex in a predictable manner.