ic4013284_si_004.cif (16.89 kB)
A Family of Layered Chiral Porous Magnets Exhibiting Tunable Ordering Temperatures
datasetposted on 2013-09-03, 00:00 authored by Matteo Atzori, Samia Benmansour, Guillermo Mínguez Espallargas, Miguel Clemente-León, Alexandre Abhervé, Patricia Gómez-Claramunt, Eugenio Coronado, Flavia Artizzu, Elisa Sessini, Paola Deplano, Angela Serpe, Maria Laura Mercuri, Carlos J. Gómez García
A simple change of the substituents in the bridging ligand allows tuning of the ordering temperatures, Tc, in the new family of layered chiral magnets A[MIIMIII(X2An)3]·G (A = [(H3O)(phz)3]+ (phz = phenazine) or NBu4+; X2An2– = C6O4X22– = 2,5-dihydroxy-1,4-benzoquinone derivative dianion, with MIII = Cr, Fe; MII = Mn, Fe, Co, etc.; X = Cl, Br, I, H; G = water or acetone). Depending on the nature of X, an increase in Tc from ca. 5.5 to 6.3, 8.2, and 11.0 K (for X = Cl, Br, I, and H, respectively) is observed in the MnCr derivative. Furthermore, the presence of the chiral cation [(H3O)(phz)3]+, formed by the association of a hydronium ion with three phenazine molecules, leads to a chiral structure where the Δ-[(H3O)(phz)3]+ cations are always located below the Δ-[Cr(Cl2An)3]3– centers, leading to a very unusual localization of both kinds of metals (Cr and Mn) and to an eclipsed disposition of the layers. This eclipsed disposition generates hexagonal channels with a void volume of ca. 20% where guest molecules (acetone and water) can be reversibly absorbed. Here we present the structural and magnetic characterization of this new family of anilato-based molecular magnets.