An electron spin resonance study of (N-2-Pyridylsalicylaldiminato)copper(II) nitrate

1975 ◽  
Vol 28 (6) ◽  
pp. 1211 ◽  
Author(s):  
TD Smith ◽  
DJ Cookson ◽  
JR Pilbrow ◽  
R Beckett
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Room Temperature ◽  
Exchange Interactions ◽  
Electron Spin Resonance Study ◽  
Magnetic Exchange ◽  
Spin Resonance ◽  
Dimeric Form ◽  
Spin Resonance Study

The magnetic susceptibility of (N-2-pyridylsalicylaldiminato)copper(II) nitrate and chloride has been measured at room temperature and 97 K. Contrary to results reported previously we find no evidence for the presence of magnetic exchange interactions in these compounds. Electron spin resonance spectral data on the ethanol-dimethylformamide solutions of the chelates show that the chelates are monomeric in the liquid phase but largely in dimeric form in frozen solution. Computer simulation of the experimental e.s.r. spectra due to the dimeric form has enabled a determination of the symmetry arrangement and structural properties of the pair system to be made.

An electron spin resonance study of certain vanadyl polyaminocarboxylate chelates formed in aqueous and frozen aqueous solutions

1974 ◽  
Vol 27 (12) ◽  
pp. 2535 ◽  
Author(s):  
TD Smith ◽  
JF Boas ◽  
JR Pilbrow
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Exchange Coupling ◽  
Electron Spin Resonance Study ◽  
Ph Titration ◽  
Weak Exchange ◽  
Spin Resonance ◽  
Dimeric Form ◽  
Firm Evidence ◽  
Spin Resonance Study

Potentiometric pH-titration and electron spin resonance studies have shown the existence of mono-meric, dimeric and dinuclear vanadyl chelates of certain polyaminocarboxylic acids. The ligands studied include ethylenediaminetetraacetic (edta), ethyleneglycolbis(β- aminoethyl ether)-N,N?-tetra-acetic (egta), diethylenetriaminepentaacetic (dtpa) and triethylenetetraaminehexaace- tic (ttha) acids. All the ligands form 1 : 1 chelates. The addition of ethylene glycol to the aqueous solution in each case provides circumstances for the study of the monomeric chelates, though it is not equally effective in all cases. The 1 : 1 vanadyl egta chelate above pH 5.5 gave rise to ΔMS = � 2 and ΔMS = � 1 transitions from which structural and magnetic parameters have been determined and interpreted in terms of the formation of a dimeric form of a hydrolytic product of the 1 : 1 chelate. Firm evidence for the formation of dinuclear chelates occurs only in the vanadyl ttha system. Here the room tem- perature e.s.r. spectrum shows the presence of weak exchange coupling between the vanadyl ions in the dinuclear chelate.

Electron spin resonance study of SO2 and CO on CuO–alumina

1982 ◽  
Vol 60 (18) ◽  
pp. 2340-2341 ◽  
Author(s):  
K. C. Khulbe ◽  
R. S. Mann
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Room Temperature ◽  
Electron Spin Resonance Study ◽  
Alumina Catalyst ◽  
Treated Sample ◽  
Spin Resonance ◽  
Spin Resonance Study

The intensity of the Cu2+ esr signal increased significantly on the addition of CO or SO2, especially with SO2, at room temperature to the preheated (at 400 °C) and evacuated CuO–alumina catalyst. When the CO or SO2 treated sample was evacuated at room temperature, the shape and intensity of the Cu2+ esr line returned to their original values. The intensity of the Cu2+ esr line decreased, but not to zero, on heating CuO–alumina either with CO or SO2. In the case of SO2, a new line appeared for the [Formula: see text] ion which was not affected on evacuation. It seems that the [Formula: see text] do not take part in the reduction of SO2 with CO over the CuO–alumina catalyst.

Electron spin resonance study of the copper(II) chelates of certain thio ligands

1970 ◽  
Vol 23 (11) ◽  
pp. 2287 ◽  
Author(s):  
JR Pilbrow ◽  
TD Smith ◽  
AD Toy
Keyword(s):  
Electron Spin Resonance ◽  
Carboxylic Acid ◽  
Electron Spin ◽  
Room Temperature ◽  
Electron Spin Resonance Study ◽  
Frozen Solution ◽  
Simulation Procedure ◽  
Spin Resonance ◽  
Frozen Solutions ◽  
Spin Resonance Study

Electron spin resonance measurements have been made on the copper(II) chelates of o-methylmercaptobenzoic acid, S-carboxydiethyldithiocarbamic acid, thiazolidine-4-carboxylic acid, 5-hydroxy-1,3-benzoxathiol-2-one and diacetyl bisthiosemicarbazone. The e.s.r. spectra of dimethylformamide solutions of the chelates have been interpreted in terms of dimeric species which are believed to exist at room temperature, as well as in frozen solutions in the case of o-methyl-mercaptobenzoic acid, S-carboxydiethyldithiocarbamic acid, and 5-hydroxy-1,3-benzoxathiol-2-one, whereas the dimeric forms of the remaining chelates are formed solely in frozen solution. The results have been interpreted as arising from dipole-dipole coupling between the copper(II) ions in their dimeric forms, and a line simulation procedure employed to extract the distance between the copper(II) dipoles. This information has been used to suggest the possible structures of the dimeric species. The effect of the introduction of zinc(II) ions during the formation of the copper(II) chelates has been assessed in each case.

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