¦¡-naphthylacetic Acid Hydrothermal Synthesis And Structure Determination Of Complexes

Due to the special chemical and electrochemical properties of aromatic carboxylate-based complexes, there is great interest in this kind of complexes. People have exploited many aromatic carboxylato ligands to produce multi-metal-containing complexes. Many complexes have some unusual properties, for example as components in homogeneous catalysts and potential applications of material sciences such as molecular sensor, and molecular magnetic and non-linear optical materials.In this paper, two binuclear complexes and one coordination polymer were obtained by treating 1-naphthalene acetic acid with metal ions in the presence of l,10-phenanthroline(phen) or 4,4'-dipyridine(4,4'-bipy) ligands under hydrothermal conditions. Furthermore, their syntheses, structural analysis, electrochemical behaviors were also studied.Firstly, a dinuclear complex, [Co₂(μ₂-NNA)₂(NNA)₂(phen)₂(H₂O)] (1) (NAA = 1-naphthalene acetic acid) has been synthesized under hydrothermal condition and characterized by single X-ray crystallography. In the complex, two Co(â…¡) ions are bridged by twoμ₂-NAA^- and the O atom of water, leading to dimeric core, [Co₂(μ2-NNA)₂(H₂O)]; each Co(â…¡) ion has an slightly distorted octahedronal coordination environment with four coordinated oxygen atoms derived from the NAA ligands and two nitrogen atoms from the phen ligand. The IR data are consistent with the crystal data of the compound.Secondly, by the similar method, another dinuclear complex [Ni₂(μ₂-NNA)₂(NNA)₂(phen)₂(H₂O)] (2) has been prepared. It is to be pointed out that the IR spectra of complex 2 are completely consistent with the product 1 in the main characteristic absorptions. This implicates that both complexes have similar coordination mode. Additional support for this suggestion is given by the elemental analysis for 2 which is in good agreement with the molecular formula.Thirdly, a novel Ni(â…¡) coordination polymer, [Ni(η²-NNA)₂(4,4'-bipy)]_n (3) , was prepared under hydrothermal condition, and was structurally characterized by means of X-ray single crystal diffraction. In polymer 3, there are three kinds of components, metal ions,η²-NNA- units, and organic bridging ligands. The bipyridine-based ligands connect Ni(â…¡) ions leading to a one-dimensional chain withη²-NNA- units acting as chelate ligands in the side chain. To the best of our knowledge, this is the first example of Ni(â…¡) coordination polymer containing the NAA ligands.