A family of layered chiral porous magnets exhibiting tunable ordering temperatures.

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[M(II)M(III)(X2An)3]·G (A = (H3O)(phz)3 (phz = phenazine) or NBu4(+); X2An(2-) = C6O4X2(2-) = 2,5-dihydroxy-1,4-benzoquinone derivative dianion, with M(III) = Cr, Fe; M(II) = 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 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.