EPR Studies of Cu2+ in dl-Aspartic Acid Single Crystals

EPR studies of Cu2+ doped dl-Aspartic Acid [NH2CH(CH2COOH)COO] powder and single crystal have been carried out at 113 and 300 K. The principal hyperfine and g values, covalancy parameter, mixing coefficients and Fermi-contact term of the complex were obtained, and the ground-state wavefuntion of the Cu2+ ion in the lattice has been constructed.

Synthesis, crystal structure, spectroscopic, fluorescent, thermal properties and EPR spectra of doped Cu2+ ions in [Cd(sac)2(H2O)2(meim)2] single crystal

The crystal structures of the six-coordinate complexes [Cd(sac)2(H2O)2(meim)2] (complex 1) formed by reaction of 4-methylimidazole(meim) with [Cd(sac)2(H2O)4]·2H2O (saccharinate=sac), was synthesized and characterized by elemental analysis, infrared (IR) and electron paramagnetic resonance (EPR) spectroscopy, thermal analysis and X-ray single crystal diffraction. X-ray diffraction analysis revealed that complex 1 crystallized in the monoclinic crystal system with space group P21/c. The Cd(II) center was six-coordinated with four nitrogen atoms from two sac and two 4-meim ligands, two oxygen atoms from two aqua ligands. Spectral and thermal analysis data for complex 1 was in agreement with the crystal structures. In addition complex 1 displayed blue fluorescent emission in the solid state at room temperature. Single crystal EPR spectra at room temperature are resolved and have exhibited that two different Cu(2+) complexes were located in different chemical environments which contained two magnetically nonequivalent Cu(2+) sites. In low temperature EPR spectra down to 110 °C did show no considerable change. At higher temperatures, however, both thermo gravimetric analyses (TGA) and EPR spectra showed detectable changes around 140 °C; the causes and the mechanisms of changes are discussed.

Thermal and EPR spectroscopic studies of novel coordination compound trans-bis(acesulfamato)tetraaquazinc(II) with Mn(II) impurity

The thermogravimetric analysis (TGA) and electron paramagnetic resonance (EPR) studies of powder and single crystals of bis(acesulfamato)tetraaquazinc(II), Zn(acs)(2)(H(2)O)(4), a novel coordination compound, are carried out. Previously synthesized bis(acesulfamato) tetraaquamanganese(II), Mn(acs)(2)(H(2)O)(4), is included into the host in trace amount as a paramagnetic probe for EPR analysis. Single crystal EPR spectra at room temperature are resolved and discussed. Low temperature EPR spectra down to 90K do not show remarkable change. At higher temperatures, however, the TGA and EPR spectra show changes around 335 K and 395 K; the causes and the mechanisms of changes are discussed.

EPR spectra of Cu(2+) doped [Zn(sac)2(dmen)] and [Zn(sac)2(paen)] single crystals

Cu(2+) doped single crystals of [Zn(sac)2(dmen)] (sac: saccharinate, dmen: N,N'-dimethylethylendiamine) and [Zn(sac)2(paen)], (paen: N,N'-bis(3-propylamine)ethylendiamine) complexes have been investigated by electron paramagnetic resonance (EPR) technique. Detailed investigations of the EPR spectra indicate that Cu(2+) ion substitute with Zn(2+) ion and forms tetrahedral complex in [Zn(sac)2(dmen)] and octahedral complex in [Zn(sac)2(paen)] hosts. Principal values of the g and hyperfine tensors are determined and the ground state wave functions of Cu(2+) ions are obtained using EPR parameters.