Synthesis, structure and magnetism of two metal(II) compounds based on two new zwitterionic ligands

• Two new compounds were synthesized from two novel zwitterionic ligands.
• Their crystal structures and magnetic properties are studied.
• The Co(II) compound induces ferromagnetic coupling, while Cu(II) compound shows antiferromagnetic coupling.

Two coordination polymers, [Co(L1)0.5(N3)2]n·3nH2O (1), [Cu3(OH)3(L2)3(H2O)1.5]n·nH2O (2), (H2L1 = 1,4-bis(4-carboxylatopyridinium-4-benzoate-1-methylene)benzene, HL2 = 4-(4-oxypyridinium-1-yl)benzotetrazolate) have been synthesized and studied by means of X-ray crystallography and magnetic analyses. Compound 1 exhibits a 2D braided grid structure, in which 1D [Co(N3)2(COO)]n chains are cross-linked by the cationic bis(pyridinium) spacers of the L1 ligand. Compound 2 is a 1D coordination chain in which the Cu(II) ions are linked by the mixed (μ-OH)(μ-N,N-tetrazolate) double bridges. The mixed (μ-EO-N3)2(COO) triple bridges transmits the ferromagnetic interaction between Co(II) ions, while the antiferromagnetic interaction between Cu(II) ions was induced by the mixed (μ-OH)(μ-N,N-tetrazolate) double bridges.

Two coordination polymer containing Co(II)/Cu(II) chains with different mixed bridges was derived from two new zwitterionic ligands; The (μ-EO-N3)2(COO) triple bridges transmit ferromagnetic interactions in 1, while the double (μ-OH)(μ-N,N-tetrazolate) antiferromagnetic interactions in 2.Figure optionsDownload as PowerPoint slide