ABSTRACT
Molecular Oxygen ........................................................................... 5 1.3 The Application of the Different Methods for Increase in
Activity and Selectivity of Homogeneous Catalysts in the Oxidation Processes ......................................................................... 6 1.3.1 Immobilization of Homogeneous Catalyst on
Heterogeneous Support for Increase in Activity and Selectivity of Catalyst in the Alkylarens Oxidations ............ 8
1.3.2 Modification of Metal Complex Catalysts with Additives of Monodentate Axial Ligands ........................... 10
1.3.3 Modeling of Transition Metal Complex Catalysts Upon Addition of Ammonium Quaternary Salts and Macro-cycle Polyethers as Ligands-Modifiers. The Role of Hydrogen – Bonding Interactions .................. 15
1.3.4 The ability of the ammonium quaternary salts as well as macrocycle polyether to form complexes with transition metals compounds was used by us to design effective catalytic systems ................................................................. 17
1.3.5 Triple Catalytic Systems Including bis (acetylacetonate) Ni(II) and Additives of Electron-donor Compound L2 and Phenol as Exo Ligands ....................................................... 24
1.4 The Role of Hydrogen-Bonding Interactions in Mechanisms of Homogenous Catalysis .................................................................. 27 1.4.1 The Effect of Small Amounts of H2O in the Ethylbenzene
Oxidation, Catalyzed with {Fe(III)(acac)3+R4NBr} System ................................................................................ 31
1.4.2 The Effect of Small Amounts of H2O in the Ethylbenzene Oxidation, Catalyzed with {Fe(III)(acac)3+18C6} System ................................................................................ 34
1.4.3 Participation of active forms of iron and nickel catalysts in elementary stages of radical-chain ethylbenzene oxidation ............................................................................. 38
1.4.3.1 Catalysis with nickel complexes............................ 40 1.4.3.2 Catalysis with iron complexes ............................... 42
1.5 Conclusion ..................................................................................... 47 Keywords ................................................................................................ 49 References ............................................................................................... 49
1.1 INTRODUCTION
The major developments in hydrocarbon oxidations have often been motivated by the need for the ever-growing polymer industry. The functionalization of naturally occurring petroleum components through reaction with air or molecular oxygen was naturally seen as the simplest way to derive useful chemicals [1]. The research of N.N. Semenov (gas-phase oxidation reactions) [2] and later N.M. Emanuel (liquid-phase hydrocarbon oxidation with molecular oxygen) [3] and others [4] clarified the concepts of chain reactions and put the theory of free-radical autoxidation on a firm basis. Industrial practice developed alongside. The development of the industrial processes depends mainly on the investigators ability to control these processes. The one of the methods of control of the rate and mechanism of the free-radical autoxidation processes is the change of medium, in which the autoxidation occurs (the pioneer works of Professor G.E. Zaikov) [5], followed by [1, 6]. The homogeneous catalysis of liquid-phase hydrocarbon oxidation has played no fewer roles in the improvement of oxidation processes. The selective oxidation of hydrocarbons with molecular oxygen as an oxidant to desired products is now a foreground line of catalysis and suggests the use of metal-complex catalysts. In the last years the development of investigations in the sphere of homogeneous catalysis with metal compounds occurs in two ways – the chain free-radical catalytic oxidation and catalysis with metal-complexes, modeling the action of ferments. But the most of the reactions performed at the industrial scale are on autoxidation reactions mainly because of low substrate conversions at catalysis by biological systems models [1, 7].
