K(I)-M(II) (M=Co, Mn) heterometallic-(perfluorinated) organic frameworks containing inorganic layered K-O-M linkages: synthesis, crystal structure, and magnetic properties

Reactions of a perfluorinated ligand, tetrafluorophthalic acid (o-H2BDC-F4), with KNO3 and M(OAc)2 (M = Co, Mn) led to the formation of perfluorinated metal-organic frameworks [CoK2(o-BDC-F4)2(MeOH)]n (1) and [MnK2(o-BDC-F4)2(DMF)]n (2). The structures were characterized by elemental analyses, infrared spectra, and single-crystal X-ray diffraction. Both complexes show similar 2-D heterometallic-organic frameworks containing unusual layered inorganic K–O–M connectivities. For 1 and 2, ortho fluorines of o-BDC-F4 are bound to the K(I) ion, while the other fluorines participate in the linkage of adjacent coordination layers forming 3-D supramolecular architectures via intermolecular FF interactions. Spectroscopic, thermal, and fluorescence properties have been investigated. Variable-temperature magnetic susceptibility studies indicate that 1 displays a weak antiferromagnetic effect between adjacent Co(II) ions.