Structural and Electron Paramagnetic Resonance Studies of the Square Pyramidal to Trigonal Bipyramidal Distortion of Vanadyl Complexes Containing Sterically Crowded Schiff Base Ligands

1997 ◽  
Vol 36 (27) ◽  
pp. 6401-6408 ◽  
Author(s):  
Charles R. Cornman ◽  
Katherine M. Geiser-Bush ◽  
Stephen P. Rowley ◽  
Paul D. Boyle
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Schiff Base ◽  
Schiff Base Ligands ◽  
Paramagnetic Resonance ◽  
Trigonal Bipyramidal ◽  
Vanadyl Complexes ◽  
Electron Paramagnetic

Heterometallic CoIII4FeIII2 Schiff Base Complex: Structure, Electron Paramagnetic Resonance, and Alkane Oxidation Catalytic Activity

2012 ◽  
Vol 51 (16) ◽  
pp. 9110-9122 ◽  
Author(s):  
Dmytro S. Nesterov ◽  
Eduard N. Chygorin ◽  
Volodymyr N. Kokozay ◽  
Volodymyr V. Bon ◽  
Roman Boča ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Schiff Base ◽  
Catalytic Activity ◽  
Complex Structure ◽  
Schiff Base Complex ◽  
Alkane Oxidation ◽  
Paramagnetic Resonance ◽  
Base Complex ◽  
Electron Paramagnetic

Structural Variation and Magneto-Structural Correlation in Two New Dinuclear Bis(µ2-Phenoxo)-Bridged CuII Schiff-Base Complexes: Catalytic Potential for the Peroxidative Oxidation of Cycloalkanes

2010 ◽  
Vol 63 (3) ◽  
pp. 479 ◽  
Author(s):  
Subhra Basak ◽  
Soma Sen ◽  
Partha Roy ◽  
Carlos J. Gómez-García ◽  
David L. Hughes ◽  
...  
Keyword(s):  
Schiff Base ◽  
Exchange Interactions ◽  
Coupling Constants ◽  
Schiff Base Complexes ◽  
Schiff Base Ligands ◽  
Paramagnetic Resonance ◽  
Catalytic Potential ◽  
Elemental Analyses ◽  
Distorted Trigonal Bipyramid ◽  
Electron Paramagnetic

Two new dinuclear bis(μ2-phenoxo)-bridged copper(ii) complexes [Cu(NCS)L1]2 (1) and [Cu(NCS)L2]2 (2) have been synthesized using two tridentate NNO-donor Schiff-base ligands, L1H (Me2N(CH2)3N=CHC6H3(OMe)(OH)) and L2H (Me2N(CH2)3N=C(CH3)C6H4(OH)), respectively. They have been characterized by elemental analyses, IR, UV-visible, and electron paramagnetic resonance (EPR) spectroscopy, cyclic voltammetry, and magnetic susceptibility measurements. X-Ray single-crystal structures reveal a central Cu2O2 core in each complex with an isothiocyanate ligand coordinated terminally to each metal centre. The coordination environments around the CuII ions in 1 and 2 are a distorted trigonal bipyramid and a quasi-regular square pyramid, respectively, with significant differences in the Cu–O–Cu bridging angles (100.22(5)° for 1 and 95.64(7)° for 2). Although both CuII dimers present intradimer antiferromagnetic exchange interactions, the magnitudes of the coupling constants in 1 and 2 (J = –119(1) and –0.361(3) cm–1, respectively) are quite different as a result of the different coordination geometries and Cu–O–Cu bridging angles. Both complexes act as promising catalysts or catalyst precursors for the efficient peroxidative oxidation of cycloalkanes (cyclohexane and cycloheptane) to the corresponding cyclic alcohols and ketones, with maximum overall yields of 53% and 56% for 1 and 2, respectively.

scholarly journals Preparation, Characterization and Antibacterial Activity of Some Metal ion Complexes

2007 ◽  
Vol 4 (4) ◽  
pp. 461-466 ◽  
Author(s):  
M. M. El-Ajaily ◽  
F. A. Abdlseed ◽  
S. Ben-Gweirif
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Antibacterial Activity ◽  
Schiff Base ◽  
Thermogravimetric Analysis ◽  
Elemental Analysis ◽  
Geometrical Structure ◽  
Analysis Data ◽  
Molar Conductance ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

The Schiff base complexes derived from Salicylaldehyde and o- pheneylenediamine have been prepared and characterized using several physical techniques, in terms; elemental analysis, molar conductance measurements, thermogravimetric analysis, magnetic moment measurements, infrared, electronic and electron paramagnetic resonance spectra. The elemental analysis data exhibit the formation of 1:1[M: L] complexes. The molar conductance values reveal a non- electrolytic nature. The thermogravimetric analysis data of Cr(VI) complex show the presence of water molecules. The obtained magnetic moment values exhibit the existence of three unpaired electrons in the Cr(III) complex and a diamagnetic phenomenon for the other three complexes. The infrared spectral data display the coordination behavior of the Schiff base towards Cr(VI), Cr(III), Pb(II)) and TiO(IV) ions. The electronic absorption spectra of the Schiff base and its complexes show π→π* (phenyl ring), n→π* (HC=N) and the expected geometrical structure for the prepared complexes. The electron paramagnetic resonance spectral data satisfy the presence of a paramagnetic phenomenon and support the expected geometrical structure of Cr(III) complex. The Schiff base and its new complexes were tested for antibacterial activity against gram positive bacteria; Staphylococcus aureus and gram negative bacteria; Salmonella, Escherichia coli including the resistance bacteria Pseudomonas aeruginosa.

Sign in / Sign up

Export Citation Format

Share Document