Michinobu Kato

Magnetic and spectral studies on copper(II) complexes with N-hydroxyalkylsalicylideneimines

Abstract The magnetic properties over the temperature range from 80°–300°K are reported for a number of copper(II) complexes with N-hydroxyalkylsalicylideneimines having empirical formulae (A) Cu(Sal·N·ROH)X and (B) Cu(Sal·N·RO), where Sal·N = · ·C 6 H 4 · H = N·, ROH = CH 2 CH 2 OH, CH 2 CH(CH 3 )OH, C(CH 3 ) 2 CH 2 OH and CH 2 CH 2 CH 2 OH, and X = Cl − , NO 3− and ClO 4− . Their magnetic properties differ depending upon the attached anion X or the R group. Of the (A) type of complexes, Cu(Sal·N·CH 2 CH 2 OH)Cl, Cu(Sal·N·CH 2 CH 2 OH)ClO 4 ·H 2 O and Cu(Sal·N·CH 2 CH(CH 3 )OH) ClO 4 ·C 2 H 5 OH exhibited antiferromagnetic behavior conforming to the Bleaney-Bowers equation, while the other complexes showed normal paramagnetic properties. For the (B) type of complexes, Cu(Sal·N·CH 2 CH 2 CH 2 O) exhibited antiferromagnetic behavior typical of binuclear copper(II) complexes, whereas the other complexes had ferromagnetic properties. The diffuse reflectance and i.r. spectra of these complexes have been measured in order to obtain information about their structure.

Magnetic and spectral studies on copper(II) halide complexes with N-ethanolsalicylideneimines☆

Abstract In order to investigate which structural factors cause the antiferromagnetic behavior in copper(II) chloride complexes with N-ethanolsalicylideneimine Cu(Sal·N·EtOH)Cl, where SaI·N·EtOH = · O 2 ·C 6 H 4 · C 1 H = N·CH 2 CH 2 OH , the magnetic and spectral properties of a series of copper(II) halide complexes with N-ethanol-5-substituted-salicylideneimines, (H, CH3, Cl and NO2), have been studied. On the basis of their magnetic, i.r. and diffuse reflectance spectral data, we have assigned a chloride-bridged binuclear structure for Cu(Sal·N·EtOH)Cl and Cu(5-CH3·Sal·N·EtOH)Cl, a phenolic oxygen-bridged binuclear structure for Cu(5-CH3·Sal·N·EtOH)-Br·0·1DMF and a phenolic oxygen-bridged linear trimetric structure for Cu3(Sal·N·EtOH)2Cl4·2C2H5OH, where 5CH 3 ·Sal=· O 2 ( C 5 H 3 )·C 6 H 3 · C 1 H= and DMF = N,N-dimethylformamide. Cu2(5-CH3·Sal·N·EtOH)Cl3·0·5H2O exhibited a higher polymeric behavior of antiferromagnetism. All the other complexes obeyed the Curie-Weiss law with very small Weiss constants, θ ≅ −2 ∼ 6°K.

Magneto-Structural Correlations in Dimeric Copper(II) Carboxylates

Abstract For dimeric copper(II) carboxylates, the most important factor determining the strength of the spin superexchange interactions is the electronic structure of the carboxylato bridge. It also has been revealed that the trigonal bipyramidal deformation of the coordination geometry around the copper atoms, and the bending of the carboxylato bridge decrease the antiferromag-netic interactions.