Transferase Biomimetic Synthesis Of 2,3 - Dihydroxynaphthalene Ligands Of Molybdenum Oxide, Characterization, And Nature Study

Molybdenum is an essential trace mineral that plays intimate roles in the global cycles of nitrate, carbon, and sulfur. It takes two forms when participated in the element metabolism, one is as inorganic salt and composed with nutrition, the other is as the cofacter of molybdeumenzy and takes part in many biochemistry reaction. Since last century 50's the research shows that there is another kind of enzyme containing molybdenum except for nitrogen enzyme, which include xanthenes oxidase, nitrate reductase, sulfite oxidase and aldehyde oxidoreductase et al. Those molybdeumenzy have important influence upon the metabolism of carbohydrate, fat, protein, sulfamino acid, nucleic acid (DNA and RNA), and iron in iron albumen.The active site structure of the molybdenum oxotransferase is likely to change during foster the molybdenumenzyme crystal because of the sensitivity and friability of the protein, which can make the result warp. There is still much to know about the surroundings of the molybdenum center. So the syntheses of the Mo-S (O/N) complexes and the researches of the structure and electron transfer of the molybdenum center can provide useful information for the crystal structure and activities studies of the molybdenumenzyme.1 Two different complexes were synthesized by the reaction of (n-Bu₄N₄) 4[Mo₈O₂₆] with 2,3-dihydroxynaphthalene in the mixed solvent of CH₃OH and CH3CN, with 1,3-propanediamine and ethyldiamine added, then 1ml of acctyl acetone was successively added at room temperature and got another two different complexes. The crystal structure result shows that the mononuclear anionic unit of the four complexes displayed the same cis-dioxo fashion with pseudo-octahedral [MoO₆] coordination geometry. The two complexes was structurally characterized by x-ray diffraction and researched with IR and UV-VIS. IR studies shows that there are characteristic absorbed peak in about 900cm^-1, which is the character of molybdenum complex with pseudo-octahedral coordination geometry.2 Two nickel complexes [Ni(NH₂CH₂CH₂CH₂NH₂)₃]Cl₂ (1) and [Ni(C₆H₅NH₂)₂Cl₂] (2) were obtained and characterized by IR and X-ray. In complex 1, the nickel is in a chiral pseudo-octahedral [NiN₆] geometry coordinated with three 1,3-propanediamine forming three six-member-ring. However in complex 2, besides ligated with two O-Phenylenediamine through four Ni-N bonds forming two five-member-rings, the nickel center is coordinated with two Cl forming trans-Ni-Cl₂, which is different from general reported diimine nickel complexes.Activated with MAO, MMAO or Et₂AlCl, these nickel complexes exhibited considerable good catalytic activity [up to 3.59×10⁶ g mol^-1 (Ni) h^-1 for complex 2] for ethylene oligomerization with main products as dimer or trimer of ethylene.