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.