Catalytic Properties Of Cu(Ⅱ)/Fe(Ⅲ) Chelates With Pyridine-like Tridentate Ligand In Oxidation

2,6-Pyridinedicarboxylic acid used as raw material,two nitrogen-containing heterocyclic compounds were synthesized,such as 2,6-bis（5-tert-butyl-1H-pyrazol-3-yl）-pyridine（btbpp）and 2,6-bis（2-benzimidazolyl）pyridine（bbp）.Various metal complexes were prepared from these ligands when coordinated with metal ions,such as Cu²⁺ and Fe³⁺.The catalytic properties of these metal complexes were investigated in the catalytic oxidation of alkene and alcohol.Important reactive factors were investigated,including reaction time,temperature,oxidants,solvents,and oxidant concentration.The dissertation contains five chapters.In the first part,we summarized the recent application and development in various fields of metal complexes with pyridine-parazole-like ligands.Combining with experimental results achieved by our research group,the idea of the research was put forward.The synthesis of the 2,6-bis（2-benzimidazole）pyridine（bbp）was firstly described in the second part.Then CPS-bbp was prepared by alkylation of 2,6-bis（2-benzimidazole）pyridine（bbp）and crosslinked chloromethylpolystyrene microspheres（CPS-Cl）,which was finally coordinated with FeCl₃·6H₂O to obtain a supported substance of Fe（Ⅲ）-CPS-bbp.The catalytic activities of the iron-complex were studied in the oxidation of styrene,α-methylstyrene and cyclohexene in CH₃CN,hydrogen peroxide（H₂O₂）and t-butyl peroxide（TBHP）used as the oxidants respectively.H₂O₂ showed strong oxidative ability and the reactions finished within 15 minutes.The selectivity of the major products prepared fromα-methylstyrene and styrene were 98.49%and 95.87%,respectively for acetophenone and benzaldehyde.Oxidation with TBHP was slow and steady,the reactions finished after 24 hours,with favorable values of selectivity onα-methylstyrene and cyclohexene obtained,97.44% and 94.82% for acetophenone andα-cyclohexenone respectively.In the third part,the metal complex btbpp-CuCl₂ was prepared by2,6-bis（5-tert-butyl-1H-pyrazol-3-yl）pyridine（btbpp）and CuCl₂.The analysis of the single crystal structure of btbpp-CuCl₂ was presented.The complexe was used as catalyst to oxidize benzyl alcohol,α-methylstyrene and cyclohexene respectively.The oxidation reactions were carried out in acetonitrile with H₂O₂ and catalytic amounts of btbpp-CuCl₂ at 70℃.Ethylbenzene and benzyl alcohol were rapidly oxidized to form acetophenone and benzoic acid repapectively,with conversion 40.64% and 97.50% in 1 h,and the selectivities of the products were 100% and 93.60%respectively.Benzaldehyde was the major product for styrene,and acetophenone for -methyl styrene.The conversions of styrene and -methyl styrene achieved 99.00% and 98.80% in 8 h respectively,and meanwhile the selectivities for benzaldehyde and acetophenone were 85.52% and 92.57% respectivelyIn the fourth part,the preparation and single crystal structures of four complexes were introduced.These complexes were prepared by 2,6-bis（5-tert-butyl-1H-pyrazol-3-yl）pyridine（btbpp）and copper salts,such as CuBr₂,Cu（NO₃）₂ and Cu（SO₃CF₃）₂.The properties of catalytic oxidation of these complexes were studied,focused on the oxidation of styrene,α-methyl styrene,benzyl alcohol and isopropyl benzene.The results showed that the complex[LCuBr₂]（H₂O）₂（L=btbpp）exihibited good catalytic performance in acetonitrile at 70℃,with H₂O₂ as oxidise.The selectivities were 100% for each product deriviated from?-methyl styrene,benzyl alcohol and isopropyl benzene.The conversions were 95.94%,35.35% and 13.85% in 2 h for each reacted compound respectively.The conversion of styrene was 75.98% in 2 h,with 88.18% selectivity for benzaldehyde.In the five part,the main achievements of the research were summarized.