ic4013284_si_004.cif (16.89 kB)
A Family of Layered Chiral Porous Magnets Exhibiting Tunable Ordering Temperatures
dataset
posted 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 GarcíaA 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.