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oai:docta.ucm.es:20.500.14352/992672024-12-14T00:45:42Zcom_20.500.14352_14col_20.500.14352_15

Tuning the magnetic properties of transition metal MOFs by metal–oxygen condensation control: the relation between synthesis temperature, SBU nuclearity and carboxylate geometry Bernini, María Platero-Prats, Ana Snejko, Natalia Gutiérrez-Puebla, Enrique Labrador, Ana Sáez Puche, Regino Romero de Paz, Julio Monge, Ángeles This work has been supported by the Spanish MCYT Project MAT2010-17571, S2009/MAT-1756/CAM and ConsoliderIngenio CSD2006–2010. The authors are grateful for the financial support for beam time at the BM16 Spanish beam line-ESRF (proposal Nu 16-01-741). A. E. P. P. acknowledges a JAE fellowship from CSIC and Fondo Social Europeo from the EU. Five novel metal organic frameworks, belonging to three structural types, have been obtained hydrothermally. Three of them, with formula [M-3(hfipbb)(2)(OH)(2)(H2O)] (M = Mn, Co, Ni; hfipbb = 4,4'-(hexafluoroisopropylidene)bis(benzoate) dianion) belong to the first structural type. The crystal structure of the Mn-based compound was obtained from single crystal synchrotron X-ray diffraction data, while the isostructural compounds of Co and Ni were studied by means of Rietveld analysis using powder X-ray diffraction data. The magnetic behavior of the compounds with M = Co and Ni is characterized by the onset of long-range ferromagnetic order at very low temperature with Curie temperatures near 8 and 2.5 K, respectively. Such spontaneous magnetization seems to be preceded by low-dimensional magnetic interactions, due to the nature of the secondary building units (SBUs) of the structure, which are triple chains built by M3O14 units. Structural and topological analyses of [Mn-2(hfipbb)(2)(H(2)hfipbb)] and [Co-2(hfipbb)(2)(H(2)hfipbb)] (2 and 3 structural types, respectively; H(2)hfipbb = 4,4'-(hexafluoroisopropylidene)bis(benzoic acid)) demonstrate that the packing of the rod-shaped SBUs in 2 prevents the framework interpenetration giving rise to a bnn net whereas 3 is a 2-fold interpenetrated pcu net with isolated paddle-wheel clusters as SBUs pcu. Concerning the magnetic behavior of 2 and 3, antiferromagnetic interactions observed at very low temperature (magnetic susceptibility maximum at 2.8 and 18 K, respectively) are confined to the secondary building units. 2024-02-06T08:40:00Z 2024-02-06T08:40:00Z 2012 journal article Bernini, M. C., Platero-Prats, A. E., Snejko, N., Gutierrez-Puebla, E., Labrador, A., Sáez-Puche, R., ... & Monge, M. A. (2012). Tuning the magnetic properties of transition metal MOFs by metal–oxygen condensation control: the relation between synthesis temperature, SBU nuclearity and carboxylate geometry. CrystEngComm, 14(17), 5493-5504. 1466-8033 10.1039/c2ce06563k https://hdl.handle.net/20.500.14352/99267 https://doi.org/10.1039/c2ce06563k eng info:eu-repo/grantAgreement/MICINN//MAT2010-17571/ES/NUEVAS ARQUITECTURAS EN QUIMICA DE MATERIALES: MOFS HACIA APLICACIONES FISICAS Y QUIMICAS SOSTENIBLES/ S2009/MAT-1756/CAM CSD2006–2010 http://creativecommons.org/licenses/by-nc-nd/4.0/ restricted access Attribution-NonCommercial-NoDerivatives 4.0 International Royal Society of Chemistry