Synthesis and crystal structures of pH-dependent Mn(II) coordination polymers with 3-pyrid-3-ylbenzoic acid

Two pyridinecarboxylato-bridged coordination polymers [Mn(pbc)2] n (1) and [Mn(pbc)2(H2O)2] n (2) (Hpbc = 3-pyrid-3-ylbenzoic acid) have been synthesized by the hydrothermal method and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. X-ray diffraction analysis reveals that pbc− adopts two coordination modes: μ 2-N, O, O and μ 3-N, O, O in 1 and as diconnectors linking two Mn(II) centers through μ 2-N, O in 2. Compound 1 is a dinuclear Mn2(pbc)2 metallocycle. Compound 2 is a double-stranded chain running along a.