76497-30-8Relevant articles and documents
Metal-nitroxyl interactions. 19. Spin-labeled derivatives of copper meso-tetraphenyl-1-(3-acrylic acid)porphyrin
More, Kundalika M.,Eaton, Sandra S.,Eaton, Gareth R.
, p. 2641 - 2647 (2008/10/08)
A series of nitroxyl spin labels have been attached via amide and ester linkages to the cis and trans isomers of copper meso-tetraphenyl-1-(3-acrylic acid)porphyrin. Values of the electron-electron coupling, J, from 0 to 600 G were observed in the electron paramagnetic resonance (EPR) spectra in fluid solution at room temperature. For the cis isomers the value of J is larger in noncoordinating solvents than in coordinating solvents. In coordinating solvents the value of J is larger for the trans isomers than for the cis isomers, consistent with the electronic spectra which indicate greater electronic interaction between the substituent and the porphyrin ring in the trans isomers than in the cis isomers. The value of J is similar for ester and amide linkages. Differences in the line widths of the EPR spectra are attributed to differences in the rigidity of the bonds between the nitroxyl ring and the porphyrin ring. For one of the trans esters, the formation of nitroxyl-halocarbon complexes was monitored by EPR and NMR.
