Oxidation of cyclohexene with tert-butylhydroperoxide and hydrogen peroxide catalyzed by alumina-supported manganese(II) complexes
TL;DR: Alumina-supported Mn(II) complexes with ligands of acetylacetonato (acac), N, N ′-ethylenebis(salicylideneiminato) (salen), ethylenediamine (en) and 2,2′-bipyridine (bpy) catalyze the oxidation of cyclohexene with tert -butylhydroperoxide (TBHP) and hydrogen peroxide as mentioned in this paper.
Abstract: Alumina-supported Mn(II) complexes with ligands of acetylacetonato (acac), N , N ′-ethylenebis(salicylideneiminato) (salen), ethylenediamine (en) and 2,2′-bipyridine (bpy) catalyze the oxidation of cyclohexene with tert -butylhydroperoxide (TBHP) and hydrogen peroxide. Oxidation of cyclohexene with TBHP gave 2-cyclohexene-1-ol, 2-cyclohexene-1-one and 1-( tert -butylperoxy)-2-cyclohexene whereas, oxidation with H 2 O 2 resulted in the formation of cyclohexeneoxide and cyclohexene-1,2-diol. Mn(II) catalysts with the nitrogen donor ligands show significantly higher catalytic activity than oxygen donor ligands at the same surface coverage. The mechanism of oxidation has also been discussed.
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TL;DR: In this article, a tetradentate Schiff base ligand was derived from the phenolic oxygen and azomethine nitrogen, and the results indicated that the Schiff base is a bivalent anion with tetralentate ONNO donors.
Abstract: New Mn(II), Co(II), Ni(II) and Cu(II) complexes of a tetradentate Schiff base ligand [bis(2-hydroxyanil)acetylacetone],“2-[{1-methyl-3-[(2-hydroxyphenyl)imino]butylidene}amino]phenol”, H 2 haacac, have been prepared and characterized by elemental analyses, IR and conductometry. The results suggest that the Schiff base is a bivalent anion with tetradentate ONNO donors derived from the phenolic oxygen and azomethine nitrogen. The formulae was found to be [M(haacac)] for the 1:1 non-electrolytic complexes. Alumina-supported [M(haacac)] complexes catalyze the oxidation of cyclohexene with tert -butylhydroperoxide (TBHP). The major products of the reaction were 2-cyclohexene-1-ol (OH), 2-cyclohexene-1-one (CO) and 2-cyclohexene-1-( tert -butylperoxy) (OO t Bu). The influence of temperature, solvent and time for the oxidation reaction has been studied. The selectivity of 2-cyclohexene-1-( tert -butylperoxy) varied with reaction temperature. Mn(haacac)-alumina shows significantly higher catalytic activity than other alumina-supported complexes.
149 citations
TL;DR: Copper(II) complexes with tetraaza[14]annulene ligands have been prepared from the one-pot template condensation reaction of substituted-1,2-phenylenediamine (4-methyl-; 4-chloro-, 4-nitro-1-2-phylenedienine) with 2,4-pentanedione in the presence of copper ion within the nanocavity pores of zeolite-Y as discussed by the authors.
Abstract: Copper(II) complexes with tetraaza[14]annulene ligands “5,7,12,14-tetramethyldibenzo-1,4,8,11-tetraazacyclotetradecine [Cu(Me4R2Bzo[14]tetraeneN4)] (R = H, CH3, Cl and NO2)” have been prepared from the one-pot template condensation reaction of substituted-1,2-phenylenediamine (4-methyl-; 4-chloro-; 4-nitro-1,2-phenylenediamine) with 2,4-pentanedione in the presence of copper(II) ion within the nanocavity pores of zeolite-Y “[Cu(Me4R2Bzo[14]tetraeneN4)]–NaY”. The new materials were characterized by several techniques: chemical analysis and spectroscopic methods (FT-IR, UV/vis, XRD, BET and DRS). The analytical data indicated a composition corresponding to the mononuclear complex of tetraaza[14]annulene. The characterization data showed the absence of extraneous complexes, retention of zeolite crystalline structure and encapsulation in the nanocavities. Encapsulated copper(II) complex is catalytically very efficient as compared to other neat complexes for the partial oxidation of benzyl alcohol and is stable to be recycled without much deterioration.
141 citations
TL;DR: In this paper, the NH2-MIL-125(Ti)@ZnIn2S4/CdS hierarchical tandem heterojunctions were fabricated through two-step solvothermal and one-step hydrothermal strategies.
Abstract: Defective-rich and electron-rich mesoporous NH2-MIL-125(Ti)@ZnIn2S4/CdS hierarchical tandem heterojunctions were fabricated through two-step solvothermal and one-step hydrothermal strategies. The interface with electron enrichment can cause active interface reaction, fast transfer and separation of charge carriers and restrain the photocorrosion of CdS. ZnIn2S4, as a bridge to connect Ti-MOFs and CdS, favors the separation of charge carriers and forms tandem heterojunctions. The as-prepared photocatalyst has a relative large surface area of ∼877.0 m2 g−1 and a narrow band gap of ∼1.84 eV, which could absorb visible light efficiently. Furthermore, it exhibits a high photocatalytic hydrogen generation rate which was increased to 2.367 mmol g−1 h−1 and the high photocatalytic degradation efficiency for 2,6-dichlorophen and 2,4,5-trichlorophenol which were 98.6% and 97.5%, respectively. Additionally, recycling text for several cycles indicates the high stability. This novel Ti-MOFs based core@shell hierarchical tandem heterojunctions may offer a new insight for fabricating high-performance heterojunctions for multi-channel charges transfer.
138 citations
TL;DR: In this paper, a tetradentate Schiff-base ligand was characterized by elemental analyses, IR, UV-vis, conductometric and magnetic measurements, and the results suggest that the symmetrical Schiff base is a bivalent anion with ONNO donors derived from phenolic oxygen and azomethine nitrogen.
Abstract: New square-planar manganese(II), copper(II), nickel(II) and cobalt(II) complexes of a tetradentate Schiff-base ligand “ N , N ′-bis-( α -methylsalicylidene)-2,2-dimethylpropane-1,3-diamine”, H 2 [Me 2 salpnMe 2 ] have been prepared and characterized by elemental analyses, IR, UV–vis, conductometric and magnetic measurements. The results suggest that the symmetrical Schiff-base is a bivalent anion with tetradentate ONNO donors derived from the phenolic oxygen and azomethine nitrogen. The formulae was found to be [M(Me 2 salpnMe 2 )] for the 1:1 non-electrolytic complexes. Alumina-supported metal complexes (ASMC); [M(Me 2 salpnMe 2 ]/Al 2 O 3 ; catalyze the oxidation of cyclohexene with tert -buthylhydroperoxide (TBHP) and hydrogen peroxide. Oxidation of cyclohexene with TBHP gave 2-cyclohexene-1-one, 2-cyclohexene-2-ol and 1-( tert -butylperoxy)-2-cyclohexene whereas, oxidation with H 2 O 2 resulted in the formation of cyclohexene oxide and cyclohexene-1,2-diol. Manganese(II) complex supported on alumina “[Mn(Me 2 salpnMe 2 ]/Al 2 O 3 ” shows significantly higher catalytic activity than other catalysts.
136 citations
TL;DR: In this article, transition metal (Mn(II), Co(II, Ni(II) and Cu(II)) complexes with tetradendate Schiff-base ligand were characterized by conductometric and magnetic measurements.
Abstract: Transition metal (M = Mn(II), Co(II), Ni(II) and Cu(II)) complexes with tetradendate Schiff-base ligand; N , N ′-bis(salicylidene)phenylene-1,3-diamine, H 2 [sal-1,3-phen]; was entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of bis(salicylaldiminato)metal(II); [M(sal) 2 ]-NaY; in the supercages of the zeolite, and (ii) in situ Schiff condensation of the metal(II) precursor complex with the corresponding phenylene-1,3-diamine; [M(sal-1,3-phen)]-NaY. The new materials were characterised by several techniques: chemical analysis, spectroscopic methods (DRS, BET, FTIR and UV–vis), conductometric and magnetic measurements. Analysis of the data indicates that the M(II) complexes are encapsulated in the nanodimensional pores of zeolite-Y and exhibit different from those of the free complexes, which can arise from distortions caused by steric effects due to the presence of sodium cations, or from interactions with the zeolite matrix. The host–guest nanocomposite materials (HGNM); [M(sal-1,3-phen)]-NaY; catalyzes the oxidation of cyclohexene with tert -butylhydroperoxide (TBHP). Oxidation of cyclohexene with [M(sal-1,3-phen)] gave 2-cyclohexene-1-one, 2-cyclohexene-1-ol and 1-( tert -butylperoxy)-2-cyclohexene whereas, oxidation with [M(sal-1,3-phen)]-NaY resulted in the formation of 2-cyclohexene-1-one and 2-cyclohexene-1-ol. [Mn(sal-1,3-phen)]-NaY shows significantly higher catalytic activity than other catalysts.
130 citations
References
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Book•
13 Aug 1993
TL;DR: Asymmetric Hydrogenation (T. Ohkuma, et al. as discussed by the authors ), asymmetric carbon-Carbon Bond-Forming Reactions (K. Nozaki & I. Negishi). Asymmetric Addition and Insertion Reactions of Catalytically-Generated Metal Carbenes (M. O'Donnell), and asymptotic phase-transfer Reactions.
Abstract: Asymmetric Hydrogenation (T. Ohkuma, et al.). Asymmetric Hydrosilylation and Related Reactions (H. Nishiyama & K. Itoh). Asymmetric Isomerization of Allylamines (S. Akutagawa, et al.). Asymmetric Carbometallations (E. Negishi). Asymmetric Addition and Insertion Reactions of Catalytically-Generated Metal Carbenes (M. Doyle). Asymmetric Oxidations and Related Reactions (R. Johnson, et al.). Asymmetric Carbonylations (K. Nozaki & I. Ojima). Asymmetric Carbon-Carbon Bond-Forming Reactions (K. Maruoka, et al.). Asymmetric Amplification and Autocatalysis (K. Soai & T. Shibata). Asymmetric Phase-Transfer Reactions (M. O'Donnell). Asymmetric Polymerization (Y. Okamoto & T. Nakano). Epilogue. Appendix. Index.
2,758 citations
Book•
01 Jan 1980
TL;DR: A perspective survey of organotransition metal complexes according to ligand substitution processes can be found in this paper, with a focus on transition metal complexes with metal carbon-bonded ligands.
Abstract: A perspective Bonding Survey of organotransition metal complexes according to ligand Ligand substitution processes Oxidative-addition and reductive elimination Intramolecular insertion reactions Nucleophilic attack on ligands coordinated to transition metals Electrophilic attacks on coordinated ligands Metallacycles Homogeneous catalytic hydrogenation, hydrosilation, and hydrocyanation Catalytic polymerization of olefins and acetylenes Catalytic reactions involving carbon monoxide Synthetic applications of transition metal hydrides Synthetic applications of transition metal complexes containing metal carbon bonds Synthetic applications of transition metal carbonyl compounds Synthetic application of transition metal carbenes and metallacycles Synthetic applications of transition metal alkene, diene, and duenyl complexes Synthetic applications of transition metal alkyne complexes Synthetic applications of -allyl transition metal complexes Synthetic applications of transition metal arene complexes.
1,795 citations
931 citations
TL;DR: In this paper, the authors dealt with enantioselective one oxygen atom transfer reactions (epoxidation, oxidation of enolates, and oxidation of sulphide to sulphoxides) catlaysed by optically active (salen)manganese(III)complexes.
907 citations
868 citations