Demonstration of Oriented Multilayers through Asymmetric Metal Coordination Chemistry

We report on the growth of oriented multilayer assemblies where the layers are connected through coordination to Zr 4+ and Hf 4+ ions. Layer orientation is achieved by asymmetric coordination at each layer. We demonstrate R−O−PO 3 2 - −M 4+ − - O 3 S−R and R−O−PO 3 2 - −M 4+ − - O 2 C−R directional coordination in multilayer assemblies. The synthetic approach to the formation of oriented multilayers is to use a ω-hydroxyalkanoic acid or a ω-hydroxyalkanesulfonic acid in combination with phosphorylation chemistry at the hydroxyl group to activate the interface at each step, allowing for the growth of additional, oriented layers. The resulting interface is resistant to chemical attack, and Fourier transform IR data reveal only limited order of the aliphatic portions of the layers.