Crystals Of Manganese Research Articles

Interaction of Valine with Biometal Chlorides in an Aqueous Environment at 25°C

Research in medical biology and pharmacology can expand understanding of the interactions of biometals with amino acids, which are key components of biological systems. This may lead to the development of new complexes that can be used in medicine, for example, to develop new drugs with antimicrobial activity or to maintain metabolic balance in the body. Research purpose:obtaining complex compounds of biometals, cobalt chloride, nickel chloride and manganese chloride with the amino acid valine, as well as the study of their physicochemical and biological properties. For the analysis, the Kjeldahl method was used to determine the nitrogen content. The composition of the formed crystals was analyzed by IR spectroscopy. The structure and shape of cobalt, nickel and manganese crystals were determined using a microscope. The identity of the obtained compounds was confirmed by IR spectroscopy and microscopic analyses. We can conclude that valine in the complex is coordinated to metal ions through the oxygen atoms of the carboxyl and nitrogen groups of the amine groups.

Interaction of Threonine with Biometal Chlorides in an Aqueous Environment at 25°C

The method for the synthesis of complexes with transition group biometal salts with the amino acid threonine includes improvement of reaction conditions, selection of reagents and analytical methods to confirm the formation of complexes. Research purpose: obtaining complex compounds of biometals, cobalt chloride, nickel chloride and manganese chloride with the amino acid threonine, as well as the study of their physicochemical and biological properties. In the synthesis of complex compounds, the preparative method was used. Compositions of the formed crystals were analyzed by IR spectroscopy. The structure and shape of cobalt, nickel and manganese crystals were determined using a microscope. The identity of the obtained compounds was confirmed by IR spectroscopy and microscopic analyses. We can conclude that threonine in the complex is coordinated to metal ions through the oxygen atoms of the carboxyl and nitrogen groups of the amine groups.

Preparation and Characterization of Paramagnetic Bis (8-Hydroxyquinoline) Manganese Crystals.

The magnetic properties of π-conjugated bis (8-hydroxyquinoline) manganese (Mnq2) crystals are investigated. Rod-shaped Mnq2 crystals are prepared by using the physical vapor deposition method. Field emission scanning electronic microscopy spectra show that the Mnq2 nanorods have perfect plane quadrangular ends. Energy dispersive spectrometer and X-ray photoelectron spectroscopy analysis demonstrates that the powders and nanorods are the same compound with a high purity. X-ray diffraction analysis shows the high crystal quality of the prepared Mnq2 nanorods. The magnetic measurement, using alternating gradient magnetometer and magnetic property measurement system superconducting quantum interference device vibrating sample magnetometer, indicates that the prepared Mnq2 nanorods show a paramagnetic property at room temperature. First-principles density functional theory (DFT) calculations are used to study the electronic structure and magnetic properties of the prepared Mnq2 crystals. DFT calculations show that the magnetic moment of the Mnq2 isolated molecule is 5 μB, which mainly comes from the localized Mn 3d orbital. The energy difference between the antiferromagnetic and ferromagnetic states of the Mnq2 monoclinic cell is only 0.1 meV, which may explain the paramagnetic property observed in the prepared Mnq2 nanorods and also indicates the difficulty of preparing intrinsic ferromagnetic Mnq2 crystals.

Effect of Manganese (Mn) – doping on crystalline and optical properties of Potassium Hydrogen Phthalate (KHP) crystals

Single crystals of Manganese (Mn)-doped Potassium Hydrogen Phthalate (KHP) were grown by slow evaporation solution growth technique using water as solvent at room temperature. The grown single crystals were analysed with powder X-ray diffraction (XRD) and estimated lattice parameters. FT-IR studies confirmed the presence of functional groups and slight distortion of groups due to doping. UV–Visible spectral studies on samples showed the improved transparency of doped crystals in the entire visible-near infrared region and calculated band gap from Tauc’s plots. The SHG efficiency studies were carried out for grown doped crystals by Kurtz-Perry powder technique.

MnBa2(HPO4)2(H2PO4)2

Crystals of manganese(II) dibarium bis­(hydrogenphosphate) bis­(dihydrogenphosphate), MnBa2(HPO4)2(H2PO4)2, were obtained by hydro­thermal synthesis. The title compound is isotypic with its CdII and CaII analogues. The structure is built up of an infinite {[Mn(HPO4)2(H2PO4)2]4−}n chain running along [100], which consists of alternate MnO6 octa­hedra and [PO4] tetra­hedra, in which the centrosymmetric MnO6 octa­hedra share their four equatorial O-atom corners with tetra­hedral [PO3(OH)] groups and their two axial apices with tetra­hedral [PO2(OH)2] groups. These chains are held together by BaO9 coordination polyhedra, developing into a three-dimensional structure. The O—H⋯O hydrogen bonds additionally stabilize the structural set-up. Due to the ionic radius of Mn2+ being much smaller than those of Ca2+ and Cd2+, this may imply that their adopted structure type has a great tolerance for incorporating various ions and the exploitation of more diverse compounds in the future is encouraged.

A single-crystal electron spin resonance study of manganese(II)-doped zinc maleate tetrahydrate

The electron spin resonance spectra of single crystals of manganese(II)-doped zinc maleate tetrahydrate have been investigated at room temperature. The transitions arise from a single type of site with gxx= 2.010, gyy= 1.992, and gzz= 2.035. The g shifts from the free spin value have been attributed to an electron-transfer process from the ligands to the S state ion. The observed angular variation of the allowed hyperfine transitions is in good agreement with theory. The spin-Hamiltonian parameters D= 360.5 × 10–4, E= 66.8 × 10–4, a=–8.9 × 10–4, and A=–87.0 × 10–4 cm–1 have been deduced. From the A value an ionicity of 96.5% is derived for the metal–ligand bonding. The analysis of forbidden hyperfine transitions leads to Q′= 1.58 × 10–4 and Q″= 0.28 × 10–4 cm–1 for the axial and rhombic components of the quadrupole coupling tensor respectively for the 55Mn nucleus.

Manganese precipitation in NaCl induced by room temperature X-irradiation

In the present paper, Electron Paramagnetic Resonance, Ionic Thermocurrents and photoluminescence (emission and excitation) measurements have been performed in crystals of manganese- doped NaCl which were exposured to room temperature X-irradiation. The results obtained indicate that the diffusion of the Mn 2+ - cation vacancy dipoles, originally present in the quenched samples, is considerably enhanced by ionizing radiation leading to the formation of a second phase precipitate which appears to be related with the Suzuki phase of the manganese ions in the host NaCl, as revealed from the EPR and optical data.

Accurate Measurements and Determination of the Magnetic Anisotropies of Several Manganese Crystals

Magnetic anisotropies of several mangane secrystals have been measured accurately between 77 K and 300 K by using a high sensitive torque-meter. As is predicted by the high temperature expansion theory, the observed magnetic anisotropies vary as the inverse square of the temperature. The crystal field splitting parameters D and E have been obtained for each pure magnetically dense sample. In compounds having the octahedron with two water molecules along the axial direction, the splitting parameters D have been found to be about -0.1 cm -1 , which value is two times or one order of magnitude larger than the typical value of Mn 2+ surrounded by a distorted octahedron composed of six similar ligands. Especially, the value | D |=0.368 cm -1 for [(CH 3 ) 3 NH]MnBr 3 2H 2 O is the largest one reported to date.