A novel coordination polymer. [Fe(C_5H_4NCOO)_2]_n, was synthesized by hydrothermal reaction and characterized by elemental analysis as well as IR spectroscopy. The crystal structure (with a novel 3-D network) of this compound belongs to monoclinic, space group P2_1/N, A = 0.49544(1) nm, b = 1.32443(2) nm, c = 1.04983(1) nm, β = 101.586(1) °. The diffuse reflectance spectra (200～2500 nm) showed that the polymer had strong absorbance in 375～563 nm (E_g ≈ 2.5 eV) region and weak absorbance from 720 to 2500 nm (near infrared spectra).

Key words: IRON CHLORIDE, PYRIDINE P, CRYSTAL STRUCTURE, ELEMENTAL ANALYSIS, IR, NIACIN, HYDRO-THERMAL REACTION