Polymer-Bound 1-Aryl-3-alkyltriazenes as Modular Ligands for Catalysis. Part 2: Screening Immobilized Metal Complexes for Catalytic Activity

2002 ◽  
Vol 12 (14) ◽  
pp. 1849-1851 ◽  
Author(s):  
Stefan Bräse ◽  
Stefan Dahmen ◽  
Frank Lauterwasser ◽  
Nicholas E. Leadbeater ◽  
Emma L. Sharp
2021 ◽  
Vol 33 (11) ◽  
pp. 2746-2754
Author(s):  
N.R. Suja ◽  
T.K. Bindu Sharmila ◽  
S.R. Amrutha

Transition metal complexes are known to be efficient catalyst for many organic transformations. Encapsulation of metal complexes in zeolite cage brings many significant modifications in the structure of the metal complexes, which are very interesting from the catalytic point of view. This study aims in a comparative evaluation of the influence of structure of neat and encapsulated complexes in their catalytic activity. Phenol is one of the major industrial pollutants. Heterogenizing transition metal Schiff bases by encapsulation inside the zeolite would help to minimize the reuse problem of transition metal complexes. This article deals with the synthesis, characterization and catalytic activity studies of Co(II), Ni(II) and Cu(II) complexes of 3-hydroxyquinoxaline-2-carboxaldehyde with ethylenediamine (L1) and an o-phenylene diamine (L2).


Author(s):  
VAIRALAKSHMI M ◽  
PRINCESS R ◽  
JOHNSON RAJA S

Objectives: The aim of our work was to synthesize novel mixed ligand-metal complexes and evaluation of antimicrobial, antioxidant assay, and analysis of catalytic oxidation of cyclohexane. Methods: The complexes were characterized by means of various physicochemical techniques such as elemental analysis, molar conductance, magnetic susceptibility, infrared (IR), electronic absorption, 1H NMR (proton magnetic resonance), and mass spectral studies. The antimicrobial screening study was done by disc diffusion method. The catalytic activity of the complexes was observed in the oxidation of cyclohexane using eco-friendly hydrogen peroxide as oxidant. Results: On comparing the 1H NMR and IR spectral data of free ligand and its complexes, it was found to be azomethine (CH=N) proton which is formed in the free ligand. During complexation, the azomethine proton is coordinated to the metal ion and the phenolic oxygen is coordinated to the metal ion by deprotonation. The analytical data and mass spectra of the ligand and the complexes confirm the stoichiometry of metal complexes as being of the (MLY)Cl type and the metal to ligand ratio is 1:1. The antimicrobial, antioxidant, and catalytic potential were evaluated and the result shows the better activity of the complexes than the ligand. Conclusion: It was found to be copper(II) and zinc(II) complexes which are effective against all the bacteria when compared to standard drug streptomycin. Copper(II) complex was found to be effective antibacterial agent against Aspergillus niger and Aspergillus flavus in comparison to the standard drug Nystatin. The zinc complex exhibited good catalytic activity.


Author(s):  
Krassimir Vassilev ◽  
Marina Dimitrova ◽  
Sevdalina Turmanova ◽  
Rumyana Milina

Kobunshi ◽  
1973 ◽  
Vol 22 (3) ◽  
pp. 131-138
Author(s):  
Hiroyuki NISHIDA ◽  
Eishun TSUCHIDA

1997 ◽  
Vol 36 (1314) ◽  
pp. 1526-1529 ◽  
Author(s):  
Manfred T. Reetz ◽  
Gunther Lohmer ◽  
Renate Schwickardi

Sign in / Sign up

Export Citation Format

Share Document