MnGaPO-2: Synthesis and Characterization of [MnGa(PO3OH)2(PO4)][C6N2H14], a New Microporous Manganese−Gallium Phosphate

A new open-framework manganese−gallium phosphate has been synthesized under solvothermal conditions and characterized by single-crystal XRD, thermogravimetric analysis, and magnetic susceptibility measurements [crystal data: [MnGa(PO 3 OH) 2 (PO 4 )][C 6 N 2 H 14 ], M r = 525.76, monoclinic, space group P 2 1 / n (No. 14), a = 10.193(1), b = 14.276(1), and c = 10.380 (1) Å, β = 91.184(8)°, V = 1510 Å 3, Z = 4, R = 5.8%, R w = 7.8% (2331 observed data with I > 3σ( I ))]. The structure consists of MnO 5, GaO 4, and PO 4 units linked to form a three-dimensional microporous framework encapsulating 1,4-diazabicyclo[2.2.2]octane cations. The Mn 2+ ions have distorted square-pyramidal geometry and exist in Mn 2 (HPO 4 ) 4 units within the framework. Antiferromagnetic ordering at T N = 10(1) K is ascribed to coupling between Mn 2+ ions in these subunits, and the temperature dependence of the susceptibility can be successfully fitted assuming a Heisenberg exchange interaction ( J = −2.07(1) cm - 1, g = 2.25(1)). At higher temperatures (>70 K) Curie−Weiss paramagnetism is observed (θ = −20.2(2) K, μ eff = 6.69(1)μ B ).