[Zurück]

E. Felbermair, J. Akbarzadeh, A. Sidorenko, U. Schubert:
"Covalent Embedding of 2D Ni²⁺-Fe³⁺ Cyanide Networks in Silica by Sol-Gel Processing";
Vortrag: 17th International Symposium on Silicone Chemistry, Berlin, Germany; 03.08.2014 - 08.08.2014; in: "ISOS XVII Berlin 2014 - Program & Abstract", (2014), ISBN: 978-3-936028-85-0; S. SL-63.

Incorporating appropriate precursors into silica sol-gel materials is a versatile tool for tuning the properties of the resulting materials. We are studying whether a ferromagnetic 2D structure may be embedded in silica gel by covalent tethering to the matrix preserving the magnetic properties and without disrupting the prior structural alignment. For this purpose we introduced trialkoxysilyl groups into the polyamine blocking ligands of [Ni(polyamine)n]3[Fe(CN)6]2 networks (n = 1, 2) and subsequently performed sol-gel reactions. The obtained materials were analysed regarding their structure (UV, IR, SEM, SAXS), as well as magnetic susceptibility (SQUID). Results for [Ni(AEAPTS)2]3[Fe(CN)6]2 (AEAPTS = N-(2-amino-ethyl)-3-aminopropyltrimethoxy-silane) in silica show ferromagnetic behaviour of the material with an effective magnetic moment µeff of 4.46 µB (corresponding to a Curie constant C of 2.50emu K mol-1) at room temperature and a maximum of 8.60 µB (9.25 emu K mol-1) at ~15 K. Two related structures, [Ni(N-monosilyl-2,3,2-tetramine)]3[Fe(CN)6]2 and [Ni(N,N´-bissilyl-2,3,2-tetramine)]3[Fe(CN)6]2 (2,3,2-tetramine = N,N´-bis(2-aminoethyl)-1,3-propane-diamine) in silica, are paramagnetic with a µeff of 6.80 µB (C = 5.80 emu K mol-1) and 5.41 µB
(C = 3.66 emu K mol-1) at room temperature, respectively.

Projektleitung Ulrich Schubert:
Anisotrope Funktionalisierung von Clustern