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E. Felbermair, U. Schubert:
"Cross-Linking of 2-Dimensional Metal Cyanide Networks by Sol-Gel Processing";
Poster: 4^th EuCheMS Chemistry Congress, Prague, Czech Republic; 2012-08-26 - 2012-08-30; in: "4^th EuCheMS Chemistry Congress - Final Program", (2012), P-242.

Ni²⁺ complexes with certain nitrogen-containing organic ligands and various metal cyanides form two-dimensional honeycomb-like analogues of Prussian Blue. The organic ligands block the four equatorial coordination sites of Ni²⁺ and thereby favour this geometrical structure.
So far, attention has mainly been directed at networks of [Ni(cyclam)]²⁺ (cyclam=1,4,8,11-tetraazacyclotetradecane) with Fe(CN)₆^3- or W(CN)₈^3-. Research has been focused on them because they possess interesting magnetic properties and microporosity. This combination leads to their classification as "magnetic sponges", which denotes materials that change their magnetic behaviour when the solvent guest molecules are removed.
We are investigating whether the magnetic properties of the materials change upon embedding the two-dimensional sheet structures in an amorphous gel. This is done by cross-linking the layers by means of trialkoxysilylalkyl groups, which are introduced by derivatising the organic blocking ligands, followed by sol-gel processing. The obtained gels are analysed regarding their structure (NMR, spectroscopic measurements, elemental analysis) as well as functionality (magnetic susceptibility, conductivity).

cyanides; Magnetic properties; microporous materials; Nickel; macrocyclic ligands

Project Head Ulrich Schubert:
Sol-Gel Prozesse mit vor-organisierten Metall-Alkoxid-Vorstufen