Auxiliary linkers-induced assembly of two 2D Co(II)-based coordination polymers with different interpenetrating fashion: Structure and magnetism

The coordination possibilities of rigid aromatic tetracarboxylate ligand with transition metal have been explored. Two new Co-II-based coordination polymers with the not fully deprotonated ligand 5,5 '-(ethene-1,2-diyl)dii-sophthalic acid) (H4L) were synthesized and characterized, incorporating different auxiliary ligands, [Co(H2L) (4,4 '-bipy)(0.5)(H2O)](n) (1) and {[Co(H2L) (dib)]center dot 2H(2)O}(n) (2) (4,4 '-bipy = 4,4 '-bipyridine, and dib = 1,4-bis(1H-imidazol-1-yl)benzene). The structural analysis related to 1 and 2 illustrated that the auxiliary linkers result in the generation of a fairly 2D (2,3)-connected framework with 4-fold interpenetration for 1 and 2D binodal (2,4)-connected network with 2-fold interpenetration. Magnetic susceptibility measurements demonstrate that 1 and 2 exhibit antiferromagnetic coupling with the corresponding J values of for 1 and 2, respectively.