Copper complexes paramagnetic

Thus, the historical development of the chemistry of metallocorrolates until 1980 includes complexes with Cu2+, Ni2+, Pd2+, Fe3+, Co3+, Rh+, Mo5+ and Cr5+. The palladium complex has been isolated as its pyridinium salt since the neutral species was too unstable to be isolated or spectroscopically characterized [19]. The nickel complex was non-aromatic, with one of the potentially tautomeric hydrogens displaced from nitrogen to carbon in such a way as to interrupt the chromophore. In contrast the electronic spectrum of the paramagnetic copper complex is similar to those of the fully conjugated lV(21)-methyl derivatives [11],... 

Copper, silver and gold - The paramagnetism of Cu11 has limited the use of NMR for the direct study of copper complexes, but information is readily obtained from studies of ligand nuclei. For example, the broadening of the NMR signal by copper in copper-zinc and copper-cobalt superoxide dismutases (SODs) has been used to determine the distance between the copper and the proton on bound formate (Sette et al., 1992). Also, broadening of the formate 13C NMR resonance reveals information about the orientation of the formate. 

Because this is a reaction of Class C, the high activity of the copper complex compared with the other metal ions should probably be explained by its having the right paramagnetic properties for performing the reaction. 

Additional information on the nature of copper complexes formed on the Ti02 surface and their relative amount has been obtained in [285]. Fig. 8.18 represents typical EPR spectra of Cu2+ ions adsorbed onto Ti02 nanoparticles at pH 3.1 and 6.0. At pH 3.1, the spectrum is typical of isolated mononuclear Cu(II) complexes. Some noticeable broadening of the ESR lines corresponding to the parallel orientation of Cu(II) complexes in the external magnetic field, which is observed even for the most magnetically diluted samples, is indicative of the existence of several paramagnetic centers with similar, but not identical structures. The increase of Cu(II) concentration results initially in an increase of... 

Like the studies with optical rotatory dispersion, studies with electron spin (paramagnetic) resonance not only have revealed important differences among the metal-free transferrins and their metal complexes but also have given insight into the nature of the binding sites and the structure of the complexes. Aasa et al. (1) reported on the iron and copper complexes of human serum transferrin and chicken ovotransferrin while Windie et al. 137) reported on human serum transferrin, human lacto-transferrin, chicken ovotransferrin, quail ovotransferrin, and turkey ovotransferrin. 

Windle, J. J., A. L. Wiersema, J. R. Clark, and R. E. Feeney Investigation of the iron and copper complexes of avian conalbumins and human transferrins by electron paramagnetic resonance. Biochemistry 2, 1341 (1963). 

Group 11. Paramagnetic (1H, 15N) NMR spectra were used to study a Cu -IDA (=iminodiacetic acid) complex localised on a protein surface. H and 13C NMR spectra were reported for copper(II) bis-benzimidazole complexes.1225 Variable temperature H NMR spectra of copper complexes of p-octafluorinated triarylcorroles reveal a thermally-accessible paramagnetic excited state, i.e. a Cu11 corrole 7i-cation radical.1226 Copper(II) forms of stellacyanin from Rhus vernicifera were characterised by H NMR.1227... 

Fig. 14. Electron paramagnetic resonance spectra of low molecular mass copper complexes in the presence and in the absence of bovine serum albumin (BSA). All four copper concentrations are identical. Cu-EDTA served as standard. Cu flonazolac) displays no EPR-signal due the antiferromagnetic coupling of the two copper-centers. After addition of BSA, a signal of the biuret-type is obtained, indicating that the original complex was disrupted. A similar signal is seen after addition of CuSO, to BSA...

Bis(p-n-decylbenzoyl)methanato-copper(II), which is similar to the molecule depicted in fig. 6.1.1 (g), but with four chains instead of eight, has been reported to exhibit a smectic-like lamellar mesophase. " A tilted smectic C type of structure has been proposed, but the disposition of the molecules in each layer does not appear to have been resolved. It is worth noting that these copper complexes were the first paramagnetic mesogens to be synthesized. 

Effect of copper-oxygen paramagnetic complexes on nuclear magnetic relaxation... 

J.J.WiNDLE, A. K. Wiersema, J.R.Clark and R.E.Feeney, Investigation of the Iron and Copper Complex of Avian Conalbumin and Human Transferrin by Electron Paramagnetic Resonance, Biochemistry, N.Y. 2, 1341—1345 (1963). 

Zweier J, Aisen P, Peisach J, Mims WB. 1979. Pulsed electron paramagnetic resonance studies of the copper complexes of transferrin. JBiol Chem 254 3512-3515. 

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