Multiscale phenomena in molecular matter

Strategies towards cyanide-based multifunctional molecular materials

7 Jul 2015, 10:40

20m

Flora Conference Room (Crown Piast Hotel)

Molecular magnets

Speaker

Dr Dawid Pinkowicz (Faculty of Chemistry, Jagiellonian University, Kraków)

Description

One of the huge advantages of molecule-based magnets over the conventional magnetic solids is their “structural plasticity” – the ability to undergo structural and magnetic changes/transitions on slight modifications by using appropriate stimuli: temperature, pressure, guest molecules, electromagnetic radiation and so on. In case of cyanide-based magnetic solids the removal/uptake of guest molecules can lead to the reversible formation/cleavage of molecular CN-bridges and the concomitant changes in their magnetic behavior. Moreover, if spin-crossover-capable ions are involved, Light-Induced Excited Spin State Trapping and the related photomagnetic effects can be expected. Additionally, pressurizing the spin-crossover capable compound influences the spin transition. Following the above outlined strategies we have successfully engineered and characterized several coordination frameworks showing solvent/ligand-induced structural changes followed by significant switching of their magnetic ordering temperature T_c [1-3]. We have also managed to observe very interesting magnetic and photomagnetic properties of cyanide-based magnetic solids in response to pressure [4,5]. The most interesting one is the pressure-induced photomagnetic effect in {[Fe^II(pyrazole)₄]₂[Nb^IV(CN)₈].4H₂O}_n recorded for the first time ever [5]. References [1] Pinkowicz, D.; Podgajny, R.; Bałanda, M.; Makarewicz, M.; Gaweł, B.; Łasocha, W.; Sieklucka, B. Inorg. Chem. 2008, 47, 9745-9747. [2] Pinkowicz, D.; Podgajny, R.; Nitek, W.; Rams, M.; Majcher, A. M.; Nuida, T.; Ohkoshi, S.; Sieklucka, B. Chem. Mater. 2011, 23, 21-31. [3] Pinkowicz, D.; Podgajny, R.; Gaweł, G.; Nitek, W.; Łasocha, W.; Oszajca, M.; Czapla, M.; Makarewicz, M.; Bałanda, M.; Sieklucka, B. Angew. Chem. Int. Ed. 2011, 50, 3973-3977. [4] Pinkowicz, D.; Kurpiewska K.; Lewiński, K.; Bałanda M.; Mihalik M.; Zentkova, M.; Sieklucka, B. CrystEngComm. 2012, 14, 5224-5229. [5] Pinkowicz, D.; Rams, M.; Mišek, M.; Kamenev, K. V.; Tomkowiak, H.; Katrusiak, A.; Sieklucka, B. submitted.