A pillared three-dimensional manganese(II) coordination network containing rectangular channels: Synthesis, X-ray structure, and magnetic properties

An unusual pillared 3-D manganese(II) coordination network based on carboxylate-bridged trimanganese cores [Mn-6(isonicotinate)(10)(H2O)(2)](ClO4)(2)(EtOH)(2)(H2O)(3), 1, was synthesized by treating manganese(II) perchlorate and 4-pyridinecarboxyaldehyde under hydro(solvo)thermal conditions. A single crystal X-ray diffraction study revealed that 1 contains rectangular channels that are occupied by perchlorate counterions and disordered ethanol and water guest molecules. The included ethanol and water guest molecules as well as the coordinated water molecules can be removed under vacuum at room temperature to afford a nanoporous solid that maintains the framework structure of 1. Magnetic measurements indicate antiferromagnetic interactions among the high-spin Mn(II) centers in 1 with coupling constants of -3.08 K and -4.96 K for the roughly isosceles triangular trimanganese cluster. Crystal data for 1: C64H62Cl2 Mn6N10O35, monoclinic space group P2(1)/n, a = 18.7892(3) Angstrom, b = 23.2307(1) Angstrom, c = 21.1355(4) Angstrom, B = 95.085(1)degrees, Z = 4, R1 = 0.0719, (w)R2 = 0.261, and GooF = 1.02. (C) 2000 Academic Press.