Magnetic properties of anhydrous and hydrated dimethylphosphinates of manganese(II). The crystal and molecular structure of poly-bis(μ-dimethylphosphinato)diaquomanganese(II)

1985 ◽  
Vol 63 (5) ◽  
pp. 1055-1062 ◽  
Author(s):  
Walter V. Cicha ◽  
John S. Haynes ◽  
Katherine W. Oliver ◽  
Steven J. Rettig ◽  
Robert C. Thompson ◽  
...  
Keyword(s):  
Heavy Atom ◽  
Indirect Evidence ◽  
Theoretical Models ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Magnetic Exchange ◽  
Distorted Octahedral ◽  
Anhydrous Compound ◽  
Manganese Compounds

The dimethylphosphinate of manganese(II), Mn[(CH3)2PO2]2, and its dihydrate have been prepared and studied using magnetic susceptibility, differential scanning calorimetry, and electronic and vibrational spectroscopic methods. The dihydrate was obtained in crystalline form and a single crystal X-ray diffraction study revealed a polymeric structure.Crystals of poly-bis(μ-dimethylphosphinato)diaquomanganese(II) are monoclinic, a = 20.722(3), b = 4.8652(2), c = 11.0689(14) Å, β = 102.209(7)°, Z = 4, space group C2/c. The structure was solved by conventional heavy-atom methods and was refined by full-matrix least-squares procedures to R = 0.030 and Rw = 0.033 for 983 reflections with I ≥ 3σ(I). The structure consists of infinite centrosymmetric chains of Mn(II) atoms linked by double phosphinate bridges and extending along the crystallographic b axis. The water molecules are involved in both interchain and bifurcated intrachain hydrogen bonding [Formula: see text], 2.899(3) and 3.120(3) Å). The coordination about Mn is slightly distorted octahedral with libration-corrected bond lengths Mn—O(phosphinato) = 2.156(2) and 2.212(2), Mn—OH2 = 2.247(2) Å.Magnetic susceptibility studies on the dihydrate from 300 to 4.2 K reveal a magnetic moment of ~5.9 BM over most of the range and give no evidence for significant magnetic exchange. The anhydrous compound, which is considered on the basis of indirect evidence to retain the double phosphinate bridged structure exhibited by the dihydrate, shows relatively strong antiferromagnetic behaviour. The data have been analyzed according to two theoretical models both of which employ the isotropic Heinsenberg Hamiltonian. The scaling model of Wagner and Friedberg gives J = −2.94 cm−1 and g = 2.02 and the interpolation scheme of Weng gives J = −2.69 cm−1 and g = 2.01. The magnitude of the exchange coupling is considered in relation to that observed in related manganese compounds and possible reasons for the observed damping of the exchange on hydration are discussed.

scholarly journals Hydrothermal Synthesis, Structural Characterization, and Interaction Mechanism with DNA of Copper(II) Complex Containing 2,2′-Bipyridine

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Ting Liu ◽  
Yi-An Wang ◽  
Qing Zang ◽  
Guo-Qing Zhong
Keyword(s):  
Fluorescence Probe ◽  
Interaction Mechanism ◽  
Distorted Octahedral Geometry ◽  
Water Molecules ◽  
Binding Modes ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Distorted Octahedral ◽  
Elemental Analyses ◽  
Polymeric Chains

A Cu(II) complex [Cu(bipy)(H2O)2(SO4)]n (bipy = 2,2′-bipyridine) was synthesized by hydrothermal method and characterized structurally by elemental analyses, single crystal X-ray diffraction, infrared spectra, and thermogravimetry and differential scanning calorimetry. The Cu(II) was hexacoordinated by two N atoms from bipy, two O atoms from different sulfate radical anions, and two O atoms from two water molecules, forming a slightly distorted octahedral geometry, and bridged by sulfato groups into polymeric chains. Under the condition of physiological pH, the interaction mechanism between the complex and hsDNA was explored with acridine orange as a fluorescence probe by spectroscopic methods. The binding modes between the complex and hsDNA were the electrostatic and embedded modes.

scholarly journals Synthesis, Characterization, and Thermal Decomposition of Pure and Dysprosium Doped Yttrium Phosphate System

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
K. K. Bamzai ◽  
Nidhi Kachroo ◽  
Vishal Singh ◽  
Seema Verma
Keyword(s):  
Thermogravimetric Analysis ◽  
Ammonium Hydroxide ◽  
Xrd Analysis ◽  
Lattice Parameter ◽  
Energy Dispersive ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Structural Investigations ◽  
X Ray

Yttrium phosphate and dysprosium doped yttrium phosphate were synthesized from aqueous solutions using rare earth chloride, phosphoric acid, and traces of ammonium hydroxide. The synthesized material was then characterized for their structural investigations using powder X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) supplemented with energy dispersive X-ray analysis (EDAX). The spectroscopic investigations were carried out using Fourier transform infrared (FTIR) spectroscopy. The thermal stability was studied using differential thermogravimetric analysis (DTA), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. X-ray diffraction analysis reveals that both yttrium phosphate and dysprosium doped yttrium phosphate belong to tetragonal system with lattice parameter  Å,  Å and  Å,  Å, respectively. The stoichiometry of the grown composition was established by energy dispersive X-ray analysis. The EDAX analysis suggests the presence of water molecules. The presence of water molecules along with orthophosphate group and metallic ion group was confirmed by FTIR analysis. Thermogravimetric analysis suggests that decomposition in case of yttrium phosphate takes place in three different stages and the final product stabilizes after 706°C, whereas in case of dysprosium doped yttrium phosphate the decomposition occurs in two different stages, and the final product stabilizes after 519°C.

Crystal structure and photophysical properties of a novel polyoxomolybdate porphyrin

2020 ◽  
Vol 76 (12) ◽  
pp. 1062-1067
Author(s):  
Wen-Tong Chen
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Reaction ◽  
Photophysical Properties ◽  
Three Dimensional ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Covalent Bonds ◽  
Hydrogen Bonding Interactions ◽  
Distorted Octahedral ◽  
Counter Cation

A novel polyoxomolybdate with a diprotonated porphyrin as counter-cation, namely, 5,10,15,20-tetrakis(4-carboxyphenyl)-21H,22H,23H,24H-porphine(2+) hexamolybdate(VI) pentahydrate, (C48H32N4O8)[Mo6O19]·5H2O or (H2TCPP)[Mo6O19]·5H2O, I, was prepared via the hydrothermal reaction of MoCl5, 5,10,15,20-tetrakis(4-carboxyphenyl)-21H,23H-porphine (TCPP) and distilled water. The crystal structure of hydrated polyoxometalate (POM) salt I was characterized by single-crystal X-ray diffraction. The compound is characterized by an isolated (zero-dimensional, 0D) structure, because it cannot extend via covalent bonds. The structure contains one [Mo6O19]2− anion, one (H2TCPP)2+ cation and five lattice water molecules. Each of the Mo6+ ions is six-coordinated and displays a distorted octahedral motif. The (H2TCPP)2+ cation displays a distorted saddle motif. A three-dimensional (3D) supramolecular framework is formed via hydrogen-bonding interactions. The compound shows a red photoluminescence emission.

Synthesis, structure, and magnetic properties of diphenylphosphinates of cobalt(II) and manganese(II). The crystal and molecular structures of the γ forms of poly-bis(μ-diphenylphosphinato)cobalt(II) and manganese(II)

1991 ◽  
Vol 69 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Jing-Long Du ◽  
Steven J. Rettig ◽  
Robert C. Thompson ◽  
James Trotter
Keyword(s):  
Magnetic Properties ◽  
Heavy Atom ◽  
Molecular Structures ◽  
Antiferromagnetic Coupling ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Lattice Constants ◽  
Linear Chains

The synthesis of the β and γ forms of M(Ph2PO2)2 where M = Co and Mn are described and the compounds are characterized by infrared spectroscopy, differential scanning calorimetry, X-ray powder diffraction, and low-temperature (2–80 K) magnetic susceptibility studies. Single crystal X-ray diffraction studies are reported on the γ forms. Crystals of the γ forms of poly-bis(μ-diphenylphosphinato)cobalt(II) and poly-bis(μ-diphenylphosphinato)manganese(II) are isomorphous, crystallizing with 4 formula units per unit-cell in the monoclinic space group P21/c. Lattice constants are a = 8.080(2), 8.161(1), b = 23.550(6), 23.751(1), c = 11.726(3), 11.6946(6) Ǻ, and β = 92.88(2), 93.026(8)° for the Co and Mn derivatives respectively. The structures were solved by heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.039 and 0.045 for 4041 and 2878 reflections with I ≥ 3σ(I), respectively. Both crystal structures consist of double phosphinate-bridged chain polymers containing tetrahedrally coordinated metal atoms: Co—O = 1.950(2)–1.963(2) Ǻ, O—Co—O = 104.81(8)–117.77(9)°, Mn—O = 2.016(3)–2.033(3) Ǻ, O—Mn—O = 103.2(1)–114.7(1)°. All four compounds exhibit antiferromagnetic coupling and magnetic susceptibilities have been analyzed according to two Heisenberg models for linear chains of metal ions with S = 3/2 for cobalt and S = 5/2 for manganese. The Weng model (with values for the Wagner and Friedberg model in parentheses) gives –J = 0.25 (0.26) cm−1 and 0.55 (0.60) cm−1 for the β and γ forms, respectively, of Co(Ph2PO2)2, and 0.34 (0.36) cm−1 and 0.17 (0.17) cm−1 for the β and γ forms, respectively, of Mn(Ph2PO2)2. Key words: crystal structure, diphenylphosphinates of cobalt(II) and manganese(II), magnetic properties.

The effect of coordinated water on the connectivity of uranium(IV) sulfatex-hydrate: [U(SO4)2(H2O)5]·H2O and [U(SO4)2(H2O)6]·2H2O, and a comparison with other known structures

2014 ◽  
Vol 70 (7) ◽  
pp. 726-731 ◽  
Author(s):  
Alexander D. Burns ◽  
Brian O. Patrick ◽  
Anita E. Lam ◽  
David Dreisinger
Keyword(s):  
Raman Spectroscopy ◽  
Binding Mode ◽  
Three Dimensions ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anhydrous Compound ◽  
Coordinated Water ◽  
Ir And Raman ◽  
Sulfate Complexes

Two new solid-state uranium(IV) sulfatex-hydrate complexes (wherexis the total number of coordinated plus solvent waters), namelycatena-poly[[pentaaquauranium(IV)]-di-μ-sulfato-κ4O:O′] monohydrate], {[U(SO4)2(H2O)5]·H2O}n, and hexaaquabis(sulfato-κ2O,O′)uranium(IV) dihydrate, [U(SO4)2(H2O)6]·2H2O, have been synthesized, structurally characterized by single-crystal X-ray diffraction and analyzed by vibrational (IR and Raman) spectroscopy. By comparing these structures with those of four other known uranium(IV) sulfatex-hydrates, the effect of additional coordinated water molecules on their structures has been elucidated. As the number of coordinated water molecules increases, the sulfate bonds are displaced, thus changing the binding mode of the sulfate ligands to the uranium centre. As a result, uranium(IV) sulfatex-hydrate changes from being fully crosslinked in three dimensions in the anhydrous compound, through sheet and chain linking in the tetra- and hexahydrates, to fully unlinked molecules in the octa- and nonahydrates. It can be concluded that coordinated waters play an important role in determining the structure and connectivity of UIVsulfate complexes.

scholarly journals Experimental and computational investigations of a cadmium(II) mononuclear complex with 2,6-Bis(3,5-dimethyl-N-pyrazolyl)pyridine (bdmpp) and selenocyanate as ligands

2009 ◽  
Vol 7 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Sinem Odabaşıoğlu ◽  
Raif Kurtaran ◽  
Akin Azizoglu ◽  
Hülya Kara ◽  
Sevi Öz ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Mononuclear Complex ◽  
Monoclinic Space Group ◽  
Ab Initio Method ◽  
Cadmium Atom ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Dft Methods ◽  
X Ray ◽  
Distorted Octahedral

AbstractA new cadmium (II) complex, [Cd(bdmpp)(SeCN)2(H2O)] (1) (where bdmpp = 2,6-bis(3,5-dimethyl-N-pyrazolyl)pyridine), has been synthesized and characterized by elemental and spectral (IR, 1H-NMR and 13C-NMR, UV-Vis) analyses, differential scanning calorimetry, and single crystal X-ray diffraction studies. X-ray analysis showed that the structure was crystallized in the monoclinic space group Cc with a = 9.031(2), b = 13.884(3), c = 16.910(3) Å, and Z = 4. The geometry around the cadmium atom is distorted octahedral with a CdN3Se2O setup. The N atoms of the SeCN are engaged in two strong intermolecular H-bonding interactions forming a 3D supramolecular polymeric network. The geometry and vibrational frequencies of complex 1 computed with the DFT methods (BLYP, B3LYP, B3PW91, MPW1PW91) are in better agreement with experiment than those obtained with the ab-initio method except for the bond angles. The molecular orbital diagram has been also calculated and visualized at the B3LYP/LanL2DZ level of theory.

Synthesis and Crystal Structure of Bis(L-α-N-(2-Pyridylmethy)phenylalaninato-N, N', O)-Zinc(II) Trihydrate

2011 ◽  
Vol 233-235 ◽  
pp. 2460-2463
Author(s):  
Qi You ◽  
Yu Cui ◽  
Guo Xin Sun ◽  
Yu Lan Yang
Keyword(s):  
Methyl Ester ◽  
Free Water ◽  
Distorted Octahedral Geometry ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Synthesis And Crystal Structure ◽  
Distorted Octahedral ◽  
Network Of Hydrogen Bonds ◽  
Phenylalanine Methyl Ester

N-(2-pyridylmethyl)-L-phenylalanine methyl ester was synthesized in our laboratory，and the title compound was synthesized by the reaction of N-(2-pyridylmethyl)-L-phenylalanine methyl ester and Zinc acetate dehydrate. Bis(L-α-N-(2-pyridylmethy)phenylalaninato-N, N', O)-Zinc(II) trihydrate was prepared and structurally characterized by X-ray diffraction. It crystallizes in orthorhombic, space group P21212 with a= 15.0928 (8), b = 16.4209 (6), c = 5.9930 (3) Å, V = 1485.29 (12) Å3, Z = 2, Mr= 630.00, Dx = 1.409 g/cm3, μ = 0.88 mm-1, F(000) = 660, Rint = 0.0205, R = 0.028 and wR = 0.059 for 2943 observed reflections with I > 2σ(I). It is a mononuclear discrete structure. The zinc atom coordinates with two oxygen and four nitrogen atoms from two ligands in a distorted octahedral geometry, with the oxygen atom from the carboxylate, two of nitrogen atoms from NH parts and the other two nitrogen atoms from the pyridine ring. With three free water molecules, the present structure has a network of hydrogen bonds.

A Dimeric Copper(II) Complex of Oxalate and Oxamide Dioxime Ligands: Synthesis, Crystal Structure, Thermal Stability, and Magnetic Properties

2014 ◽  
Vol 69 (3) ◽  
pp. 321-326 ◽  
Author(s):  
Justin Nenwa ◽  
Patrick L. Djonwouo ◽  
Emmanuel N. Nfor ◽  
Michel M. Bélombé ◽  
Erwann Jeanneau ◽  
...  
Keyword(s):  
Layer Structure ◽  
Variable Temperature ◽  
Thermal Analyses ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Centrosymmetric Dimer ◽  
Weight Losses ◽  
Network Variable ◽  
Distorted Octahedral ◽  
Coordinated Water

The dimeric copper(II) complex [Cu(C2O4)(H2oxado)(H2O)]2 (1), where H2oxado=oxamide dioxime, has been synthesized in water and characterized by elemental and thermal analyses, IR spectroscopy, and single-crystal X-ray diffraction. Complex 1 is composed of two neutral [Cu(C2O4)(H2oxado)(H2O)] entities connected by Cu-O bonds between oxalate oxygen atoms and copper(II) ions, thereby producing a centrosymmetric dimer, with the Cu(II) centers exhibiting a strongly distorted octahedral coordination. Neighboring dimers are hydrogen-bonded through O- H···O interactions leading overall to a layer structure. Thermal analyses of complex 1 showed two significant weight losses corresponding to the coordinated water molecules, followed by the decomposition of the network. Variable-temperature (10 - 300 K) magnetic susceptibility measurements revealed very weak antiferromagnetic interactions (θ = 0:86 K from Curie-Weiss law behavior) within the dinuclear unit

A Rare Example of a Dinuclear Cobalt(II) Complex with Dipicolinate and Bridging 2-Aminopyrazine Ligands. Preparation, Structural, Spectroscopic and Thermal Characterization

2011 ◽  
Vol 66 (8) ◽  
pp. 813-818 ◽  
Author(s):  
Masoumeh Tabatabaee ◽  
Boris-Marko Kukovec ◽  
Vajieh Razavimahmoudabadi
Keyword(s):  
Dipicolinic Acid ◽  
3D Structure ◽  
Thermal Characterization ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
Distorted Octahedral ◽  
Elemental Analyses ◽  
Coordinated Water ◽  
Oxygen Atoms

A dinuclear cobalt(II) complex, [Co2(H2O)4(dipic)2(μ-apyz)] (dipicH2 = pyridine-2,6-dicarboxylic (dipicolinic) acid, apyz = 2-aminopyrazine) (1), has been hydrothermally synthesized and characterized by elemental analyses, spectroscopic methods (IR, UV/Vis), thermal analysis as well as by X-ray diffraction studies. The dinuclear complex is composed of two cobalt(II) ions bridged by a 2-aminopyrazine molecule. Each cobalt(II) ion is coordinated by one nitrogen and two oxygen atoms of the tridentate dipicolinate anion, one heterocyclic nitrogen atom of the 2-aminopyrazine and two oxygen atoms of coordinated water molecules. The resulting geometry for the CoN2O4 coordination environment can be described as distorted octahedral. Various hydrogen bonds of the type O-H···O and N-H···O are also present in the crystal structure. This arrangement leads to the formation of a 3D structure.

Pyrazine and 2,5-dimethylpyrazine complexes of copper(I) trifluoromethanesulfonate. The crystal and molecular structure of poly-μ-2,5-dimethylpyrazine-(2,5-dimethylpyrazine)-(trifluoromethanesulfonato-O)copper(I)

1990 ◽  
Vol 68 (10) ◽  
pp. 1901-1907 ◽  
Author(s):  
Tom Otieno ◽  
Steven J. Rettig ◽  
Robert C. Thompson ◽  
James Trotter
Keyword(s):  
Crystal And Molecular Structure ◽  
Copper Ions ◽  
Heavy Atom ◽  
Electronic Spectroscopy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Full Matrix ◽  
X Ray ◽  
Neutral Ligands ◽  
Spectroscopy Studies

The complexes CuL2(CF3SO3) where L is pyrazine and 2,5-dimethylpyrazine have been prepared by the reaction of copper(I) triflate with the neutral ligand in methanol. Single crystal X-ray diffraction studies on the 2,5-Me2pyz complex are reported. Crystals of the compound are triclinic, a = 9.424(4), b = 12.103(4), c = 9.113(4) Å, α = 110.97(3), β = 117.20(3), γ = 80.26(3)°, Z = 2, space group [Formula: see text]. The structure was solved by heavy atom methods and was refined by full-matrix least-squares procedures to R = 0.033 and Rw = 0.039 for 3326 reflections with I ≥ 3σ(1). The structure is similar to that of the pyz analogue involving chains of copper ions linked by bridging 2,5-Me2pyz ligands and monodenate triflate and terminal 2,5-Me2pyz ligands completing a distorted tetrahedral CuN3O chromophore. Mono-pyrazine and -2,5-dimethylpyrazine complexes of the type CuL(CF3SO3) were obtained by thermolysis of the corresponding bis-ligand complexes. These compounds are assigned a polymeric structure involving bridging neutral ligands and monodenate triflate groups on the basis of infrared spectroscopy studies. Electronic spectroscopy and differential scanning calorimetry studies are also reported. Keywords: pyrazine and 2,5-dimethylpyrazine complexes, copper(I) triflate, crystal structure.

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