Copper-complex, zeolite-encapsuled

C. R. Jacob, S. R. Varkey, and R. Ratnasamy, Zeolite encapsulated copper (X2-Salen) complexes, Appl. Catal. A 168, 353-364 (1998). 

Iron-phthalocyanine (Fe-Pc) encapsulated in Y and VPI-5 zeolites were used for the oxidation of alkanes or olefins in presence of t-butylhydroperoxide or H2O2 (Fig. 9). Fe-Pc-Y also catalyzed the oxidation of cyclohexane to cyclohexanol and cyclohexanone with t-butylhydroperoxide ( TBHP ). Ruthenium perfluorophthalocyanine complexes encapsulated in NaX ( Ru-Fi6 Pc-X ) were active for the oxidation of cyclohexane with TBHP at room temperature.Manganese(II) bipyridyl complexes in faujasite ( Y ) zeolite are active for the oxidation of cyclohexene to adipic acid in the presence of H2O2 at room temperature. Similarly oxidation reactions have been reported using copper complexes encapsulated in X,Y, and VPI-5 molecular sieves. 

Chaudhari et al. reported encapsulation of copper complexes in zeolite-Y and MCM-41 or by tethering of copper complexes on various supports like zeolite-Y, silica, charcoal, or clay [87]. These materials were then characterized by a plethora of sophisticated analytical techniques like EPR, diffused reflectance UV-vis, XRD, IAS, ICPES, SEM, and TEM and employed for the amination of aryl iodide to synthesize diphenyl aniline or triphenyl amine (Scheme 21). 

The oxidation of phenol, ortho/meta cresols and tyrosine with Oj over copper acetate-based catalysts at 298 K is shown in Table 3 [7]. In all the cases, the main product was the ortho hydroxylated diphenol product (and the corresponding orthoquinones). Again, the catalytic efficiency (turnover numbers) of the copper atoms are higher in the encapsulated state compared to that in the "neat" copper acetate. From a linear correlation observed [7] between the concentration of the copper acetate dimers in the molecular sieves (from ESR spectroscopic data) and the conversion of various phenols (Fig. 5), we had postulated [8] that dimeric copper atoms are the active sites in the activation of dioxygen in zeolite catalysts containing encapsulated copper acetate complexes. The high substratespecificity (for mono-... 

Encapsulated Cu—chlorophthalocyanines oxidize hexane at C-l using 02 and at C-2 using H202 as oxidants. The dimeric structure of copper acetate is intact when it is incorporated into the zeolite. This is a regioselective aromatic hydroxylation catalyst, which mimics the specificity of the monooxygenase enzyme tyrosinase.82,89 Zeolite NaY catalysts made with a tetranuclear Cu(II) complex were synthesized and characterized.90... 

S. Chavan, D.Srinivas, and R. Ratnasamy, Structure and catalytic properties of dimeric copper(II) acetato complexes encapsulated in zeolite-Y, J. Catal. 192, 286-295 (2000). 

Y. Ukisu, A. Kazusaka, and M. Nomura, Preparation and Catalysis of a Copper-Pyridine Complex Encapsulated into a Zeolite Supercage. J.Mol. Catal., 1991, 70, 165-174. 

Dimeric copper acetate complexes encapsulated in zeolite Y (and MCM-22) exhibited increased activity in the phenol hydroxylation with dioxygen, compared to the homogeneous system [73]. Again a dimeric complex is stabilized in the zeolite cages, as can be derived... 

Maurya, M., Chandrakar, A. andChand, S. (2007). Zeolite-Y Encapsulated Metal Complexes of Oxovanadium(VI), Copper(ll) and Nickel(II) as Catalyst for the Oxidation of Styrene, Cyclohexane and Methyl Phenyl Sulfide, J. Mol Catal A Chem., 274, pp. 192-201. 

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