Polyoxometalates (POMs) are discrete clusters of redox-active metal oxides, many of which can be linked to organic moieties. Here, we show how it is possible to link Mn Anderson POMs to terminal alkyne and azide groups and develop appropriate conditions for their Cu-catalyzed alkyne-azide cycloaddition (or "click" reaction). These coupling reactions are then used to link the clusters together, forming monodisperse linear Mn Anderson oligomers, here with examples ranging in size from two to five clusters. These oligomers are built up sequentially using a combination of mono- and difunctionalized clusters, giving an unprecedented level of control over the size and structure of the resulting hybrid POMs. This new synthetic methodology therefore opens the way for the synthesis of metal oxide hybrid oligomers and polymers by coupling control, minimizing side products, producing nanosized molecular hybrid organic-inorganic oxides ca. 4-9 nm in size, with molecular weights ranging 2-10 kDa.

Herein, we report a hybrid polyoxometalate organic–inorganic compound, Na2[(HGMP)2Mo5O15]⋅7 H2O (1; where GMP=guanosine monophosphate), which spontaneously assembles into a structure with dimensions that are strikingly similar to those of the naturally occurring left‐handed Z‐form of DNA. The helical parameters in the crystal structure of the new compound, such as rise per turn and helical twist per dimer, are nearly identical to this DNA conformation, allowing a close comparison of the two structures. Solution circular dichroism studies show that compound 1 also forms extended secondary structures in solution. Gel electrophoresis studies demonstrate the formation of non‐covalent adducts with natural plasmids. Thus we show a route by which simple hybrid inorganic–organic monomers, such as compound 1, can spontaneously assemble into a double helix without the need for a covalently connected linear sequence of nucleic acid base pairs.

Wir berichten hier über ein hybrides organisch-anorganisches Polyoxometallat, Na 2 [(HGMP) 2 Mo 5 O 15 ]·7 H 2 O (1)( mit GMP = Guanosinmonophosphat), das sich spontan zu einer Struktur zusammenfügt, deren Dimensionen jenen der natürlich vorkommenden linkshändigen Z-Form der DNA verblüffend ähnlichs ind. Die Helixparameter in der Kristallstruktur dieser neuen Verbindung,w ie Anstieg pro Windung und helikale Verdrillung pro Dimer,sind nahezu identisch zur DNA, was einen eingehenden Vergleich von beiden Strukturen erlaubt. Zirkulardichroismus (CD) in Lçsung zeigt, dass Verbindung 1 auchi nL çsung ausgedehnte Sekundärstrukturen aufweist. Gelelektrophorese-Untersuchungen weisen die Bildung nichtkovalenter Addukte mit natürlichen Plasmiden nach. Damit kçnnen wir einen Wegaufzeigen, auf dem einfache, hybride organisch-anorganische Monomere,w ie in Verbindung 1,s ich spontan zu einer Doppelhelix zusammenlagern kçnnen, ohne dass dazu eine kovalent gebundene lineare Sequenz von Nuklein-Säure-Base-Paaren nçtig wäre.