H. Wayne. Richardson

Single crystal magnetic susceptibility measurements on the linear chain polymer copper (II) pyrazine nitrate

Magnetic susceptibilities have been measured in the temperature region 1.7–60°K both parallel and perpendicular to the chemical chain on single crystals of Cu(pyrazine)(NO3)2. It has been shown that there is qualitative disagreement between experiment and theory if the appropriate equations derived for the Ising model in one dimension are applied. On the other hand, excellent agreement exists for the Heisenberg model with J/k = −5.3°K down to the lowest temperature achieved, along with closer agreement between the g values determined in this experiment and those obtained by EPR. A comparison is also made between the exchange pathway in Cu(NO3)2 · 2.5H2O and the probable pathway in Cu(pyrazine)(NO3)2.

Magnetic properties of linear chain compounds: copper(II) complexes with 2-(o-hydroxyphenyl)-benzoxazole and -benzothiazole

Abstract The magnetic susceptibility behavior of the copper(II) complexes of 2-( o -hydroxyphenyl) benzoxazole and 2-( o -hydroxyphenyl) benzothiazole has been examined over the temperature range 2–77°K. Despite established linear chain structure both complexes exhibit negligible spin exchange coupling. The present work provides additional support of an earlier conclusion that out-of-plane copper-oxygen distances of 2.8A or greater are too long to transmit spin-spin interactions.

Electronic Structure of Pseudotetrahedral Copper(II) Schiff Base Complexes

Copper(II) complexes with the Schiff bases formed by condensing t-butyl-, isopropyl-, cyclohexyl- and diphenylmethylamines with salicylaldehyde and 3-methoxy- and 5-nitrosalicyl-aldehyde have been prepared and characterized. The isotropic nuclear hyperfine coupling constants increase in the order t-butyl < isopropyl < cyclohexyl < diphenylmethyl for the N-substituents in the three series of complexes while isotropic g-values increased in the opposite direction. Spectra structure correlations were examined and discussed.