Susceptibility Of Polycrystalline Samples Research Articles

Trinuclear copper(II) complexes based on iminodiacetic acid salicylidenehydrazone

Nickel, copper, and zinc complexes with salicylidenehydrazone of iminodiacetic acid (H4L): Cu2L · 2Py · 2CH3OH and Cu2ML(CH3COO)2 (M= Ni, Cu, Zn) were synthesized and studied by thermo-gravimetric analysis and IR and ESR spectroscopy. The crystal structure of the complex Cu2ZnL(CH3COO)2 · 4Py · CH3OH was studied by X-ray diffraction: space group C2/c, a = 31.6974(12) A, b = 10.3023(4) A, c = 16.4714(7) A; β = 119.7460(10)°; Z = 4; 3513 reflections with I > 2σ(I); R = 0.0382, Rw = 0.1010. The temperature dependences of the ESR spectra of liquid solutions and the magnetic susceptibility of polycrystalline samples were studied. The ESR spectra of the binuclear copper complex and the trinuclear dicopper zinc complex exhibited hyperfine structure of seven lines, indicating exchange interaction of unpaired electrons with two equivalent copper nuclei.

Paramagnetic Susceptibilities of Some DPPH Derivatives

Abstract The static magnetic susceptibilities of poly crystalline samples of 1,1-bis(p-chlorophenyl)-2-picrylhydrazyl (Cl-DPPH), 1,1-bis(p-bromophenyl)-2-picrylhydrazyl (Br-DPPH), and 1,1-bis (p-methoxyphenyl)-2-picrylhydrazyl (CH3O-DPPH) were measured in the temperature range from 10°K to 300°K. These three substances showed strong paramagnetism comparable to that of DPPH, having relatively weak interaction energies between their unpaired electrons. Of these, the paramagnetic susceptibility of CH3O-DPPH was analysed on the basis of the singlet-triplet model with the energy separation of 2J/k=33.8°K.