No abstract

Besonders effektiv: Durch Selbstorganisation von Triazacyclonan‐funktionalisierten Thiolen auf der Oberfläche von nanometergroßen Goldpartikeln sind funktionalisierte Goldnanopartikel einfach zugänglich. Durch Komplexierung mit ZnII werden sie zu leistungsfähigen Katalysatoren für die Spaltung von Phosphatestern (siehe Schema). Wegen ihres RNase‐artigen Verhaltens werden sie Nanozyme genannt.

A protocol is reported for the preparation of water-soluble, thiol-protected Au nanoparticles (Au-MPC) where dioctylamine is used as a stabilizing agent when the gold cluster is formed using the two-phase Brust and Schiffrin procedure. The amount of amine controls the size of the nanoparticles in the 1.9-8.9 nm diameter range. The final stabilization of the gold clusters by addition of functionalized thiols is performed under very mild conditions compatible with most biomolecules. The procedure is suitable for a wide variety of functional groups present in the thiol and allows one to use thiol mixtures with a precise control of their composition in the monolayer. As a proof of principle, examples of nanoparticles protected with thiols comprising functional groups ranging from polyethers, saccharides, polyamines and ammonium ions are reported.

The ZnII complexes of triazacyclononane-functionalized DAB dendrimers are powerful catalysts for the cleavage of an RNA model substrate with clear evidence of cooperativity between two metal centers.