Synthesis, Structures And Properties Of Containing (Benzimidazol-2-yl) Ligands And Their Complexes

The benzimidazole derivatives and their complex compounds possess significant theoretical studies and application in biology, material and catalysis fields due to their excellent biological activity. And these compounds containing benzimidazol-2-yl group are also important. So we designed and synthesized a series of ligands possessing benzimidazol-2-y) and their metal complexes. Meanwhile, we have constructed coordination complexes by using 1,10-phenanthroline and 2-（4-cyano-3-fluorophenoxy）acetic acid and transition metal salts under hydrothermal conditions. These molecules and molecular assemblies have been characterized with the aid of elemental analysis, IR spectrum, ultraviolet-visible spectroscopy, fluorescence spectrum, NMR, thermogravimetric analysis and electrochemistry.1. 12 Benzimidazol-2-yl-containing ligands have been designed and synthesized: 1,5-bis（benzimidazol-2-yl）-3-thiopentane （L₁）,2-（（benzimidazol-2-yl）methoxy） phenol （L₂）, 2-bis（（benzimidazol-2-yl）methoxy）benzene （L₃）, l,3-bis（（benzimidazol -2-yl）methoxy）benzene （L₄）, l,4-bis（（benzimidazol-2-yl）methoxy）-benzene （L₅）, 2-（（2-methoxyphenoxy）methyl）benzimidazole （L₆）,8-（（benzimidazol-2-yl）methoxy） quinoline （L₇）, 2-（（quinolin-8-ylamino）methyl）-benzimidazole （L₈）,2,5-bis （（benzimidazol-2-yl）methylthio）-l ,3,4-thiodiazoles （L₉）,2-（（benzoxazol-2-yl）thiomethyl）benzimidazole (L₁₀),2-（（benzimidazol-2-yl）methoxy）benzaldehyde (L₁₁),2-（（naphthalen-1-yl）oxy- methyl）benzoimidazole (L₁₂). The structures of L₂, L₇, L₁₂ were determined by single-crystal X-ray diffraction show that all atoms of complexes are almost conplane and one water molecule exist in every crystal cell. The two non-covalent bond interaction of hydrogen bonds mediated through the water molecule andπ-πstacking acted through each ligand molecule are played an important role in stability of the crystal cell.2.7 novel metal complexes were constructed by using the transitional metal salts with L₇ and L₉: [Cu（L₇）Cl₂] （M₁）, [Cu（L₇）（H₂O）SO₄·2H₂O]_n（M₂）, [Cd₂（L₇）₂Cl₄·Cd（L₇） （H₂O）C1₂]·H₂O （M₃）, [Cu（L₇）₂（ClO₄）₂]·2H₂O（M₄）, [Co（L₇）₂（ClO₄）₂]·3H₂O （M₅）, [(Ni（L₇）₂（ClO₄）₂]·2H₂O （M₆） and [Cd（L₉）₂（CH₃OH）₂]·（NO₃）₂ （M₇）. The structures of M₁, M₂, M₃, M₇ were determined by single-crystal X-ray diffraction showed that: The geometry of the copper（Ⅱ） in complex （M₁） is trigonal bipyramida; One-dimensional double chain is constituted by the polymer complex （M₂） of center copper（Ⅱ） ion bridged through sulfate ligands; The complex（M₃） are constituted by two assemblies in ratio of 1:1 with the two center cadmium（Ⅱ） ion in six-coordinated geometry, one of assemblies possesses ’Cl’ bridge structure; And the geometry of the center cadmium（Ⅱ） in complex（M₇） is perfect regular octahedron. In addition, M₁, M₂ and M₃ have a pair of redox peak respectively; M₁ and M₃ possess fine fluorescence property, but the fluorescence of M₇ is quenched.3. 2 metal complexes were constructed by using the transitional metal salts with 1, 10-phenanthroline under hydrothermal conditions: [Cu（phen）（H₂O）₂SO₄]_n, [Zn（phen）₃]·（ClO₄）₂（phen 1,10-phenanthroline）. The structures of the above metal complexes were determined by single-crystal X-ray diffraction showed that: Double chain is constituted by the polymer complex （[Cu（phen）（H₂O）₂SO₄]_n） of center copper（Ⅱ）ion bridged through sulfate ligands; The center zinc（Ⅱ） in complex([Zn（phen）₃]·（ClO₄）₂ is six-coordination geometry.In addition,the ultraviolet-visible spectroscopy of the two complexes all shift red and the intensity of fluorescence compared to ligand is weak,but the fluorescence of [Cu（phen）（H₂O）₂SO₄]_n is quenched.4. The 2-（4-carboxyl-3-fluorophenoxy）acetic acid with copper metal complexes（[Cu（CFPOAH）₂（H₂O）₂]） was synthesized by using the transitional metal salts with 2-（4-cyano-3-fluorophenoxy）acetic acid （CFPOAH） under hydrothermal conditions and its structure determined by single-crystal X-ray diffraction showed that the geometry of center metal is distorted octahedron.