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.     

EPR studies of Cu2+ in tetraaqua-di(nicotinamide) Zn(II)-saccharinate single crystals

Electron paramagnetic resonance (EPR) studies of copper ions, Cu(II), as paramagnetic impurity in tetraaqua-di(nicotinamide) Zn(II)-saccharinates single crystals [Zn(nic)2(H2O)4](sac)2, have been investigated at ambient temperature. The detailed EPR analysis shows the only one site and the copper ion entered the lattice substitutionally in place of Zn(II). The spin-Hamiltonian parameters were obtained from the single crystal EPR analysis. By using the EPR data, molecular bonding coefficient and the Fermi contact interaction terms have been evaluated. Superhyperfine splittings were observed.     

An EPR study of Cu2+ doped [Na(Hmal)(H2O)5] single crystals

The magnetic environments of Cu²⁺ doped Na⁺ complex have been identified by electron paramagnetic resonance (EPR) technique. The angular variation of the EPR spectra has shown that two different Cu²⁺ complexes are located in different chemical environments, and each environment contains one magnetic Cu²⁺ site occupying substantial positions in the lattice and showing very high angular dependence. The principal g, and the hyperfine structure parameter (A) values of two sets of Cu²⁺ complex groups are determined. The covalency parameter, mixing coefficients and Fermi-contact term of the complex are obtained, and the ground state wave function of the Cu²⁺ ion in the lattice has been constructed.     

Synthesis and characterization of [Cu(mb2en)2]ClO4 and [Cu(mb2en)(PPh3)2]BPh4: crystal structure of [Cu(mb2en)2]ClO4

The ligand, N,N′-bis-(4-methoxy-benzylidene)-ethane-1,2-diamine (mb₂en), and its corresponding copper(I) complexes, [Cu(mb₂en)₂]ClO₄ (1), and [Cu(mb₂en)(PPh₃)₂]BPh₄ (2), have been synthesized and characterized by CHN analyses, ¹H and ¹³C-NMR, IR, and UV-Vis spectroscopies. The crystal and molecular structure of [Cu(mb₂en)₂]ClO₄ (1), were determined by X-ray crystallography from a single-crystal. The coordination polyhedron about copper(I) is best described as a distorted tetrahedron. Quasi-irreversible redox behavior was observed for 1 and 2 (E _1/2?=?0.55 and 0.95?V, respectively).     

EPR and optical absorption studies of Cu2+ doped bis (glycinato) Mg (II) monohydrate single crystals

Electron paramagnetic resonance (EPR) study of Cu²⁺ doped bis (glycinato) Mg (II) monohydrate single crystals is carried out at room temperature. Copper enters the lattice substitutionally and is trapped at two magnetically inequivalent sites. The observed spectra are fitted to a spin-Hamiltonian of rhombic symmetry with the following values of the parameters: Cu²⁺ (I), g_x = 2.1577 ± 0.0002, g_y = 2.2018 ± 0.0002, g_z = 2.3259 ± 0.0002, A_x = (87 ± 2) × 10^?4 cm^?1, A_y = (107 ± 2) × 10^?4 cm^?1, A_z = (141 ± 2) × 10^?4 cm^?1; Cu ²⁺ (II), g_x = 2.1108 ± 0.0002, g_y = 2.1622 ± 0.0002, g_z = 2.2971 ± 0.0002, A_x = (69 ± 2) × 10^?4 cm^?1, A_y = (117 ± 2) × 10^?4 cm^?1and A_z = (134 ± 2) × 10^?4 cm^?1. The ground state wave function of the Cu²⁺ ion in this lattice is evaluated to be predominantly |x² ? y². The g-factor anisotropy is also calculated and compared with the experimental value. With the help of the optical absorption study, the nature of bonding in the complex is discussed.     

Theoretical study of EPR spectra for Mn2+ ion in [Mg(H2O)6]SnCl6 single crystal

The relationship between the impurity structures and the electron paramagnetic resonance (EPR) parameters D, (a-F) have been studied by diagonalizing the complete energy matrices for Mn2+ ion in [Mg(H2O)6]SnCl6 single crystal in a trigonal ligand field within a weak-field-representation. It is shown that the local lattice structure around Mn2+ ion in [Mg(H2O)6]SnCl6 exhibits an elongation distortion which is different at 290 K and 77 K. The local structure parameters R=2.223+/-0.027A, theta=52.966+/-0.004 degrees and R=2.205+/-0.030A, theta=53.155+/-0.047 degrees for Mn2+ ion in [Mg(H2O)6]SnCl6 are determined at different temperatures 290 K and 77 K, respectively, and EPR parameters D and (a-F) can also get a satisfactory explanation simultaneously.     

Crystal structure and single crystal EPR of (NH4)2(15-crown-5)3[Cu(mnt)2] and (NH4)2(benzo-15-crown-5)4[Cu(mnt)2]·0.5H2O

The X-ray crystal structures of (NH4)2(15-crown-5)3[Cu(mnt)2] (1) and (NH4)2(benzo-15-crown-5)4- [Cu(mnt)2]·0.5H2O (2) were determined. Two single crystals are composed of distinct structures of ammonium-crown ether supramolecular cation and [Cu(mnt)2]2- anion. The triple-decker dication in complex 1 and a sandwich dimmer in complex 2 were observed. X-Band EPR studies on the single crystals of both complex 1 and complex 2 have been carried out at room temperature, which revealed that complex 2 showed a perfect hyperfine structure of Cu whereas that of complex 1 could not be observed. The principal values and direction cosines of the principal axes of the g and A tensors were computed by a least-squares fitting procedure. The spin density of Cu(Ⅱ) was estimated according to the principal values of the A tensors and compared well with the results calculated based on DFT method.     

Direct synthesis, crystal structures, high-field EPR, and magnetic studies of heterometallic polymers containing manganese(II) carboxylates interconnected by [Cu(en)2]2+

Two heterometallic polymers containing cations [Cu(en)2]2+ and either the [Mn(mal)2(H2O)2]2- (1) or [Mn2(succ)2Cl2]n2n- (2) anions (mal=malonate and succ=succinate) were investigated by X-ray crystallography, high-field electron paramagnetic resonance (EPR) spectroscopy, and magnetic susceptibility measurements. Magnetic susceptibility and EPR spectra characteristic of antiferromagnetically coupled Mn2+-Mn2+ pairs were observed in 2, and the exchange integral J=31 cm(-1) (H=JS1S2) as well as the zero-field-splitting parameter D=-3.046 cm(-1) in the triplet state of the dimanganese entity was determined.     

Electron paramagnetic resonance and optical studies of Cu2+ doped bis(thiourea)cadmium chloride single crystal

Electron paramagnetic resonance (EPR) and optical studies have been carried out on Cu²⁺ doped bis(thiourea)cadmium chloride single crystal, which belongs to a potential semi-organic non-linear material, at room temperature. The spin Hamiltonian parameters were determined as g_xx = 2.04331, g_yy = 2.04373, g_zz = 2.05750 and A_xx = 91G, A_yy = 115G, A_zz = 136G. These parameters suggest that the spectroscopic splitting parameter g and hyperfine splitting parameter A exhibit rhombic symmetry. The optical study reveals that the non-linear optical property of the host lattice has been enhanced due to Cu²⁺ doping.     

EPR and optical absorption studies of Cu2+ doped L-arginine phosphate monohydrate single crystals--part II

The EPR spectra of Cu2+ ion in L-Arginine phosphate monohydrate (LAP) at X-band frequencies at room temperature reveal the presence of two magnetically inequivalent interstitial Cu2+ sites in the lattice. The principal values of the g- and A-tensors indicate rhombic symmetry around the Cu2+ ion. From the direction cosines of the principal values of the g- and A- tensors, the orientations of the sites in the lattice have been identified. The bonding parameters were evaluated and the ground state wave function of Cu2+ ion was constructed. The ground state is found to be an admixture of [x2 - y2> and [3z2 - r2> orbitals. The optical absorption studies show four bands centered at 9803, 10753, 15748 and 16666 cm(-1) confirming the rhombic symmetry around the Cu2+ ion. Using the observed bands the crystal field parameters have been evaluated.     

Single crystal EPR and optical absorption studies of Cu2+ ion in L-arginine sulphophosphate monohydrate--a nonlinear optical crystal

The EPR spectra of Cu2+ ion in L-arginine sulphophosphate monohydrate (LASP), a nonlinear optical material (NLO) have been studied at room temperature. Two magnetically inequivalent interstitial Cu2+ sites in the lattice were identified. The principal values of g- and A-tensors indicate that the symmetry of the electrostatic field around the Cu2+ ion is rhombic. Bonding parameters have been evaluated and the ground state wave function of Cu2+ ion is constructed. The ground state is found to be an admixure of x2 - y2 and 3z2 - r2 orbitals. By correlating EPR and optical absorption spectra the crystal field parameters have been evaluated.     

EPR, optical and infrared absorption studies of Mn2+ ions doped in zinc malate trihydrate single crystal

Electron paramagnetic resonance (EPR) studies have been carried out on Mn2+ ions doped in zinc malate trihydrate single crystals in the temperature range 123-413 K on X-band frequency. The EPR spectrum at room temperature exhibits a group of five fine structure transitions each splits into six hyperfine components. Angular variation studies reveal that Mn2+ ions enter the lattice substitutionally. From the observed EPR spectrum, the spin-Hamiltonian parameters have been evaluated. The variation of zero-field splitting parameter (D) with temperature is measured. From the optical absorption spectrum, the crystal field splitting parameter Dq and the Racah interelectronic repulsion parameters B and C have been evaluated. The infrared spectrum exhibits bands characteristic of the carboxylic acid salts.     

[Cu(en)_2]V_6O_(14)晶体的水热合成、晶体结构和电化学性质

通过水热方法合成了一种三维无机-有机多金属钒酸盐[Cu(en)_2]V_6O_(14),并测定了其晶体结构.该化合物经过X-射线单晶衍射、元素分析、红外光谱表征和热失重分析,并研究了它的电化学性质.     

Synthesis,Characterization, and Crystal Structures of [Cu(ca2en)2]ClO4, and [Cu(ca2en)(PPh3)2]ClO4 Complexes

Synthesis, spectroscopy, and crystal structures of [Cu(ca₂en)₂]ClO₄ ( 1 ) and [Cu(ca₂en)(PPh₃)₂]ClO₄ ( 2 ) (ca₂en=N,N′‐bis(trans‐cinnamaldehyde)ethylenediimine) are reported. Compound 1 crystallizes in the orthorhombic space group Pbca, with a=12.5647(7), b=21.8203(11), c=27.992(2) Å, V=7674.3(7) ų, Z=8. Compound 2 crystallizes in the triclinic space group P , with a=13.0540(11), b=14.2935(13), c=14.9863(13) Å, α=84.130(2), β=69.761(2), γ=87.749(2)°, V=2609.8(4) ų, Z=2. The coordination polyhedron about the Cu^I center in the two complexes is best described as a distorted tetrahedron. The ¹H‐NMR and electronic spectra of these complexes are also reported and discussed. The cyclic voltammetry of the complexes indicate a quasireversible redox behavior for complex 1 (E_1/2=0.51 V). However, complex 2 displays an irreversible oxidation wave at 0.91 V. A weak emission is observed for complex 2 in CHCl₃ at room temperature.     

以有机溶剂热生长技术制备金属硫族化合物 [Mn(en)~3]PdSe~2及其晶体结构分 析

以有机溶剂热生长技术(solvothermaltechnique),即在180℃乙二胺(en)溶液中,以MnCl~3,PdCl~2,K~2Se在密闭容器中反应7d,制备出新的硫族化合物[Mn(en)~3]PdSe~2,其阴离子基团为[PdSe~2]^2^-,阳离子基团为过渡金属Mn与乙二胺(en)的配合物：[Mn(en)~3]^2^+。以单晶X射线衍射技术解得该晶体结构属正交晶系,空间群为Pbcn,[Mn(en)~3]PdSe~2(Ⅰ)的晶胞数据：a=1.1484(2),b=1.5057(3),c=0.93622(19)nm,Z=4。     

Halogenomercurate: Darstellung und Strukturen von [Cu(en)2][Hg2Cl6], [Cu(en)2][Hg2Br6] und [Cu(en)2][HgBr4]

Halomercurates: Syntheses and Crystal Structures of [Cu(en)₂][Hg₂Cl₆], [Cu(en)₂][Hg₂Br₆], and [Cu(en)₂][HgBr₄] Crystals of [Cu(en)₂][Hg₂Cl₆] ( 1 ) have been obtained by layering a solution of Hg(NO₃)₂ and NaCl with a solution of [Cu(en)₂]SO₄. An analogous procedure, using NaBr instead of NaCl, gave crystals of [Cu(en)₂][HgBr₄] ( 3 ). Crystals of [Cu(en)₂][Hg₂Br₆] ( 2 ) were obtained by gel crystallization using the same starting materials as for 3 . The complexes show very low solubility. The dinuclear anions of 1 consist of two nearly planar HgCl₃ units related by a center of symmetry. In 2 infinite anionic chains are present, made up of parallel HgBr₃ units. These units are packed in such a way as to produce a trigonal bipyramidal configuration around the Hg atoms. 3 contains mononuclear deformed tetrahedral [HgBr₄]^2– anions. In all three complexes the packing of the ions is such that halogen atoms of halomercurate anions complete a tetragonal bipyramidal coordination at Cu. The resulting Cu–Halogen distances are 2.924 Å for 1 , 3.036 Å for 2 and 3.085 and 3.119 Å for 3 . 1 : Space group P 1, Z = 1, lattice constants at 20 °C: a = 7.000(2), b = 7.526(2), c = 8.239(2) Å; α = 88.39(2), β = 86.06(2), γ = 86.10(3)°; R₁ = 0.040. 2 : Space group P2₁/c, Z = 2, lattice constants at –50 °C: a = 7.185(1), b = 16.338(2), c = 7.814(1) Å; β = 94.88(2)°; R₁ = 0.033. 3 : Space group P2₁/n, Z = 4, lattice constants at 20 °C: a = 8.055(3), b = 13.101(3), c = 13.814(3) Å; β = 91.24(3)°; R₁ = 0.092.