Novel Mn(II)-Based Metal–Organic Frameworks Isolated in Ionic Liquids

An unprecedented series of Mn²⁺-based metal–organic framework (MOF) materials prepared and isolated in ionic liquids (ILs) is reported. Ionothermal reactions of Mn­(OAc)₂ with H₃btc (benzene-1,3,5-tricarboxylic acid) in two groups of [rmi]­X (rmi = 1-alkyl-3-methylimidazolium; r = ethyl or propyl, X = Cl, Br, or I) ILs produced three slightly different 3D MOFs formulated as [rmi]­[Mn­(btc)] [r = ethyl (1), propyl (2), and (3)], whose architectures can be envisaged as (3,6)-connected pyr topological nets. Compounds 1–3 are the preferred products when the metal center is half filled d-shelled Mn with the cations of ILs being [emi]⁺ or [pmi]⁺. The comparison of the ionothermal synthesized M-btc systems suggests a significant combinatorial influence of metal-direction and ILs’ cationic template, contrasting with subtle effect of ILs’ halides on the MOF structures.