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D. Müller, C. Knoll, Jan Welch, G. Giester, M. Reissner, P. Weinberger:
"Spin-switchable Hofmann-type networks based on tetrakis(cyanoacetylides): Larger pores for larger guests";
Vortrag: ACS Spring Meeting 2019, Orlando; 31.03.2019 - 04.04.2019; in: "Chemistry for New Frontiers", American Chemical Society (Hrg.); (2019), ISBN: 978-0-8412-3433-8; Paper-Nr. 504, 1 S.

Spin-switchable Hofmann-type Fe(II)-networks based on M(CN)₄ (M=Ni, Pd, Pt) as square planar building block and a ditopic N-heterocycle as e.g. pyrazine, 4,4´-bipyridine,... combine magnetism with host-guest chemistry. Methods for introduction of complementary properties such as luminescence, magnetism or host-guest chemistry into spin-switchable metal organic frameworks involve the proper selection of the building blocks, as well as suitable design of pore structure and diameter.
A second generation of extended Hofmann-type networks was obtained by introduction of an acetylene-unit in the M-CN bond, resulting in metallated tetrakis(cyanoacetylides) as expanded building blocks. Thereby, not only a notable increase in pore volume of about 120 % was achieved, but the polarity of the PCP´s inner surface could also be modified. This enables incorporation of larger guest molecules as e.g. small fluorophores.
For the growth of single-crystals a novel electrolytic crystallization approach was developed, providing the necessary Fe(II)-ions by anodic oxidation of Fe in a non-aqueous medium.
In the contribution the second generation of bimetallic Fe-M, (M=Ni, Pd, Pt) Hofmann-type networks is presented and discussed with regard to its structural, magnetic and spectroscopic properties. The special emphasis of this contribution is placed on the host-guest chemistry of the networks, as governed by the extended pores bearing alkyne-moieties.

host-guest chemistry; MOF; spin-crossover; iron(II)