Recent advances in supramolecular coordination chemistry allow access to transition-metal complexes of grid-type architecture comprising two-dimensional arrays of metal ions connecting a set of organic ligands in a perpendicular arrangement to generate a multiple wiring network. General design principles for these structures involve the thermodynamically driven synthesis of complex discrete objects from numerous molecular components in a single overall operation. Such supramolecular metal ion arrays combine the properties of their constituent metal ions and ligands, showing unique optical, electrochemical, and magnetic behavior. These features present potential relevance for nanotechnology, particularly in the area of supramolecular devices for information storage and processing. Thus, a dense organization of addressable units is represented by an extended "grid-of-grids" arrangement, formed by interaction of grid-type arrays with solid surfaces.

Periodic Mesoporous Organosilicas (PMOs) were developed in 1999 and are basically ordered templated mesoporous organosilicas, prepared by the combination of a surfactant as template and a silsesquioxane as the organosilica precursor. They were one of the first examples of the so-called "hybrid" organic/inorganic materials. In the years that followed, an amazing variety of functional groups, morphologies and applications has been developed. Some of these high-end applications, like low-k buffer layers in microelectronics, chiral catalysts, chromatographic supports, selective adsorbents and light-harvesting devices, have clearly shown their potential. In this review, we will give a comprehensive overview of all these different functionalities and applications that have been created for Periodic Mesoporous Organosilicas.

The self-assembly of the ligands 1 a ± d, containing tridentate binding subunits, with lead(ii) ions lead to the formation of the supramolecular inorganic architectures 2 ± 4 of [2 Â 2], [3 Â 3], and [4 Â 4] grid-type containing four, nine, and sixteen lead(ii) ions, respectively, in octahedral coordination sites. The structures have been assigned on the basis of the spectroscopic data in solution, and confirmed in the case of 2 a in the solid state by X-ray radiocrystallography. The entities 2 ± 4 display specific arrays of metal ions and are of potential interest for the development of devices for molecular electronics. Their formation, in particular that of 4, stresses the power of correctly designed selfassembly processes to generate highly complex architectures of well-defined geometry and nanometric size in a spontaneous but controlled fashion, without having to resort to nanofabrication procedures.

Jüngste Entwicklungen auf dem Gebiet der supramolekularen Koordinationschemie haben Übergangsmetallkomplexe mit Gitterstruktur ins Blickfeld der Forschung gerückt. Die Synthesen dieser komplexen molekularen Einheiten beruhen auf Selbstorganisationsprozessen, in denen die Zielverbindungen durch Koordination organischer Liganden an Metallionen in einer Stufe aus einer Vielzahl von Komponenten thermodynamisch gesteuert aufgebaut werden. Die organischen Liganden und die Metallionen bestimmen die photophysikalischen, elektrochemischen und magnetischen Eigenschaften der Gitterkomplexe, zusätzlich können jedoch auch “kollektive” Eigenschaften auftreten. Funktionelle Gitterkomplexe sind interessant für die Nanotechnologie, z. B. hinsichtlich der Entwicklung einer (supra)molekularen Informationsspeicherung und ‐verarbeitung. Das Aufbringen dieser Komplexe auf Oberflächen führt zu ausgedehnten matrixartigen Anordnungen von Metallionen mit bisher unerreichten Dichten adressierbarer Elemente.