Synthesis, Characterization And Catalytic Epoxidation Of Molybdenum (Ⅵ) Complexes With Schiff Base Ligands And The Ligands Supported On Mixed Zirconium Phosphate-phosphonates

The epoxidation of olefins is an important routine to synthesize epoxides and plays an important role in organic synthesis. In this paper, firstly, the inexpensive tris(hydroxymethyl)amino methane (THAM) and D-glucosamine were used as the starting materials, 11 kinds of Schiff base molybdenum(â…¥) complexes were synthesized under mild conditions and characterized by element analysis, IR, Raman, UV-Vis, ¹H NMR and ¹³C NMR. The highest yields of cyclohexene epoxidation catalyzed by the molybdenum (â…¥) complexes of 2-Hydroxymethyl-2-[(2-hydroxy-5-nitro-benzylidene)-amino]-propane-1, 3-diol [MoO₂(H₂L⁴)(MeOH)] was up to 98.7%. Among the Schiff base molybdenum(â…¥) complexes derived from D-glucosamine, while the hydroxyl groups of D-glucosamine were protected by acetyl groups, not only the catalytic activities and selectivity in the cyclohexene epoxidation, but also the diasteroisomeric selectivity in the styrene epoxidation were greatly improved, compared with those unprotected D-glucosamine Schiff base molybdenum(â…¥) complexes. Up to 47.2% of e.e.value was obtained with 3-4f as catalyst.A new type of organic-inorganic mixed supports, zirconium (oligostyrenyl-phosphonate-phosphate) were designed and synthesized, then proper ligands were introduced into the supports to prepare series of molybdenum complexes supportedon these kinds of supports which functionalized with polyamines and polyethylene glycols. The supports and the corresponding molybdenum complexes catalysts were characterized by element analysis, IR, Raman, GPC, SEM, XPS, XRD; and the structure of catalysts were deduced therefore. Due to the fact that nitrogen is a strongly coordinating and donating atom, molybdenum complexes supported on the zirconium (oligostyrenylphosphonate-phosphate) functionalized with the polyamines showed poor selectivity in cyclohexene epoxidation, and the catalytic activities and selevtivity gradually decreased with the increasing of the number of nitrogen atoms in the ligands. The best result was obtained with ZrSPP-en-Mo as catalyst that was over 99.5% of conversion but only about 89% of selectivity. The catalytic activities and selevtivity could be greatly improved, which gave close to 100% of conversion and 97.8% of selectivity for some reactions (for example ZrSPP-digly-Mo), just by the polyethylene glycols instead of polyamines in the catalysts. Therefore this kind of catalysts showed good reusability and promised tobe new environmental benign green catalysts.At last, 20 kinds of copper (IT) and cobalt (H) complexes derived from THAMwere synthesized, characterized and their interactions with DNA were studied by SERS spectra. The results indicated that some complexes had strong interactions with DNA and promised to be a new type of anti-cancer drugs with high activities and low toxicity.