Manganese(II) Oxazolidine Nitroxide Chelates: Structure, Magnetism, and Redox Properties

2014 ◽  
Vol 67 (11) ◽  
pp. 1618 ◽  
Author(s):  
Ian A. Gass ◽  
Mousa Asadi ◽  
David W. Lupton ◽  
Boujemaa Moubaraki ◽  
Alan M. Bond ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Intramolecular Interaction ◽  
Variable Temperature ◽  
Field Measurements ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility ◽  
Radical Interaction

The mononuclear oxazolidine nitroxide complex [MnII(L•)2](ClO4)2 (1) (L•, 4-dimethyl-2,2-di(2-pyridyl)oxazolidine N-oxide) has been synthesized and investigated using single-crystal X-ray diffraction, variable-temperature magnetic susceptibility measurements, and electrochemistry. The structural analysis reveals bond lengths compatible with a linear L•–MnII–L• arrangement where the ligands are in the neutral ligand form and the central MnII ion is high spin (S = 5/2). Although analysis of the variable-temperature magnetic susceptibility data suggests a strong antiferromagnetic metal–radical interaction, the radical–radical intramolecular interaction could not be determined unambiguously from such fits. The resultant isolated S = 3/2 ground state is confirmed by low-temperature magnetization versus field measurements. Electrochemical studies reveal similar square schemes and redox intermediates to the previously reported analogues [FeII(L•)2][BF4]2 and [CoII(L•)2][NO3]2.

New Copper(II) and Nickel(II) Complexes with Bifunctional Tetrazolate-5-carboxylate Ligands: Syntheses, Crystal Structures, and Magnetic Properties

2009 ◽  
Vol 62 (12) ◽  
pp. 1622 ◽  
Author(s):  
A-Qing Wu ◽  
Qi-Yong Chen ◽  
Mei-Feng Wu ◽  
Fa-Kun Zheng ◽  
Feng Chen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Variable Temperature ◽  
Supramolecular Network ◽  
X Ray Diffraction ◽  
Carboxylate Ligands ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility ◽  
Network Variable

Four new complexes with bifunctional tetrazolate-5-carboxylate ligands of 1H-tetrazole-5-formic acid (H2tzf) and 1H-tetrazole-5-acetic acid (H2tza), namely two dinuclear [M(tzf)(H2O)3]2·2H2O (M = Cu 1, Ni 2) and two mononuclear [Cu(tzf)(2,2′-bipy)2]·5H2O 3 and Cu(tza)(2,2′-bipy)H2O 4, were prepared and structurally characterized by single-crystal X-ray diffraction. Two different coordination modes of tetrazolate-5-carboxylate ligands exist: a tridentate N,O-chelated-N-bridged mode in 1 and 2, and a bidentate N,O-chelated mode in 3 and 4, which was first observed for the tetrazolate-5-carboxylate complexes. Extensive hydrogen bonds play an important role in the construction of the supramolecular network. Variable-temperature magnetic susceptibility data show the presence of antiferromagnetic interactions in 1 and 2. The thermogravimetric analyses of complexes 1–4 are also discussed.

A new binuclear NiII complex with tetrafluorophthalate and 2,2′-bipyridine ligands: synthesis, crystal structure and magnetic properties

2019 ◽  
Vol 74 (11-12) ◽  
pp. 833-838 ◽  
Author(s):  
Jun-Xia Li ◽  
Zhong-Xiang Du ◽  
Xun Feng
Keyword(s):  
Variable Temperature ◽  
Ferromagnetic Coupling ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility ◽  
Niii Complex ◽  
Weak Ferromagnetic ◽  
Dinuclear Structure

AbstractA new NiII compound, [Ni2(tfpa)2(bipy)2(H2O)4] (1) with tetrafluorophthalate (tfpa2−) and 2,2′-bipyridine (abbreviated as bipy) ligands, has been synthesized and structurally characterized. The single-crystal X-ray diffraction analysis reveals that the tfpa2− anions act as bis-monodentate linkers connecting NiII centers to form the dinuclear structure of 1. The dimeric units are stabilized by intramolecular π–π stacking and are further connected into a layer through O–HLO hydrogen bonding. Variable-temperature magnetic susceptibility data in the 10–200 K temperature range indicate weak ferromagnetic coupling between the two NiII ions.

Ferromagnetic interactions in a dicyanamide-bridged multinuclear metal-organic framework [Pr3NH]+ [Mn(dca)3]−·H2O

2019 ◽  
Vol 74 (6) ◽  
pp. 485-489
Author(s):  
Yuan Huang ◽  
Xiu-feng Yu ◽  
Zhen Rong ◽  
Yi-chun Ai ◽  
Kun Qian ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Measurements ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Metal Organic ◽  
Ferromagnetic Interactions

AbstractA new complex [Pr3NH]+ [Mn(dca)3]− · H2O (dicyanamide = dca−) was synthesized, in which the Mn2+ cations are bridged by end-to-end dca anions to form three-dimensional [Mn(dca)3]nn− networks and tripropylammonium cations reside in the cavities of these networks. The complex has been characterized by single-crystal X-ray diffraction, infrared spectroscopy, elemental analysis, and magnetic measurements. Magnetic susceptibility data indicate ferromagnetic interactions among the MnII ions.

Synthesis, Structures and Magnetic Properties of a Family of One-Dimensional Oxides

1996 ◽  
Vol 453 ◽  
Author(s):  
H.-C. Zur Loye ◽  
P. Núñez ◽  
M. A. Rzeznik
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Rietveld Refinement ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
One Dimensional ◽  
X Ray ◽  
Susceptibility Data ◽  
The One

AbstractThe one-dimensional compounds Sr3MgPtO6, Sr3MgIrO6, Sr3MgRhO6, Sr3GdRhO6, have been synthesized and structurally characterized by Rietveld refinement of powder X-ray diffraction data. All four compounds are isostructural with the rhombohedral K4CdCl6-type structure. The structure consists of infinite one-dimensional chains of alternating face-shared MO6 octahedra (M = Pt, Ir, Rh) and M′O6 (M′ = Gd, Mg) trigonal prisms. The strontium cations are located in a distorted square antiprismatic environment. Magnetic susceptibility data show that both Sr3MgIrO6 and Sr3MgRhO6 obey the Curie-Weiss law with θ = −6(1) K, and θ= −15(3)K, respectively. Sr3GdRhO6 obeys the Curie law with μeff = 7.80 B.M, consistent with an oxidation state of +3 for both rhodium and gadolinium.

Preparation, electrochemical behavior, and variable-temperature magnetic properties of Co(3,5-DBSQ)2 complexes of imidazole- or pyrazole-substituted ligands

2015 ◽  
Vol 93 (7) ◽  
pp. 769-774 ◽  
Author(s):  
Carolyn Dowling ◽  
Danielle R. Dinsdale ◽  
Martin T. Lemaire
Keyword(s):  
Magnetic Susceptibility ◽  
High Spin ◽  
Density Functional ◽  
Variable Temperature ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Magnetic Susceptibility Data ◽  
Valence Tautomerism ◽  
Susceptibility Data ◽  
Variable Temperature Magnetic Susceptibility

Herein we describe the preparation of four new Co(3,5-DBSQ)2 containing known 2-(2-pyridyl)benzimidazole 1, 2,2′-bisbenzimidazole 2, or 2,2-(1H-pyrazole-3,5-diyl)dipyridine 3. We investigate the electronic and variable-temperature magnetic susceptibility properties of these complexes. Complexes containing 2 and 3 are bimetallic and variable-temperature magnetic susceptibility data suggest observation of a stable intermediate (high-spin and low-spin) state for the bimetallic complex with 3, which does undergo valence tautomerism. Complexes 4–6 containing imidazole-based ligands 1 and 2 feature high-spin ground states and no valence tautomerism is observed in these materials. This experimental finding is corroborated with density functional theory calculations, which support the existence of a stable high-spin ground state in these complexes.

Synthesis, crystal structure, and magnetic properties of the complex [(CH3)3NH]2 [Co(NCS)4]

2018 ◽  
Vol 73 (8) ◽  
pp. 571-575
Author(s):  
Yang Jie ◽  
Huang Yuan ◽  
Zhong YouQuan ◽  
Fang Ting ◽  
Hao Fan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Infrared Spectroscopy ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Ferromagnetic Interactions

AbstractA new complex [(CH3)3NH]2[Co(NCS)4], in which zero-dimensional [Co(NCS)4]n2− anions are balanced by 2n [(CH3)3NH]+ cations, was synthesized. The complex has been characterized by single X-ray diffraction, infrared spectroscopy, elemental analysis, and magnetic measurements. Magnetic susceptibility data indicate ferromagnetic interactions among the CoII ions.

Syntheses, Crystal Structures and Magnetic Properties of Cr(NCNH2)4Cl2 and Mn(NCNH2)4Cl2

2012 ◽  
Vol 67 (11) ◽  
pp. 1205-1211 ◽  
Author(s):  
Xiaojuan Tang ◽  
Manfred Speldrich ◽  
Andrei L. Tchougréeff ◽  
Richard Dronskowski
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Quantum Theory ◽  
Transition Metal Ions ◽  
Chloride Ions ◽  
Many Body ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data

The two isotypic compounds Cr(NCNH2)4Cl2 and Mn(NCNH2)4Cl2 have been synthesized and characterized by X-ray diffraction. They crystallize in the cubic space group Im3̄m (Z = 6) with a = 12:643(2) Å for Cr(NCNH2)4Cl2 and a = 12:821(1) Å for Mn(NCNH2)4Cl2. The divalent transition metal ions are octahedrally coordinated by four H2NCN molecules in equatorial and two chloride ions in axial positions. The magnetic susceptibility data of the four Curie-paramagnetic compounds Cr(NCNH2)4Cl2, Mn(NCNH2)4Cl2, Co(NCNH2)4Cl2, and Ni(NCNH2)4Cl2 have been analyzed in greater detail, including many-body quantum theory.

Structural and Magnetic Characterization of Mixed Oxides: A Study of Li-Ni-O and Li-Mn-O Systems

1998 ◽  
Vol 53 (3-4) ◽  
pp. 150-156
Author(s):  
V. Massarotti ◽  
D. Capsoni ◽  
M. Bini ◽  
C. B. Azzonia ◽  
M. C. Mozzati ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Mixed Oxides ◽  
Spinel Phase ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Paramagnetic Ions ◽  
Profile Refinement

The present paper details the way to determine the cation distribution in mixed oxides with transition ions from the diffraction and magnetic susceptibility data. This approach allows one to determine phase abundances and phase compositions by two combined procedures. By X-ray diffraction Rietveld profile refinement and magnetic susceptibility data analysis it is possible to estimate the ratio and the occupancy factor of paramagnetic ions in different oxidation states. A brief discussion of practical cases is reported. In the Li-Ni-O system the lithium cationic fraction of the ordered phase Li2xNi2-2XO2 increases monotonically with the total lithium fraction xtfor 0.31 < xt< 0.46. In the Li-Mn-O system for 0.36 ≤ xt ≤ 0.53 the Li2MnO3 fraction has been determined, and for the coexistent Li [LiyMn2-y]O4 spinel phase the dependence of y on xthas been evaluated.

Synthesis and Structure of Some MII/MIII Mixed Fluorides with Pyrochlore and Weberite Related Structures

2006 ◽  
Vol 61 (7) ◽  
pp. 808-812 ◽  
Author(s):  
M. A. Subramanian ◽  
W. J. Marshall ◽  
R.-D. Hoffmann ◽  
A.W. Sleight
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Susceptibility ◽  
Single Crystals ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Antiferromagnetic Ordering

New NH4MIIMIIIF6 and MIIMIIIF5 ・ 2H2O compounds with the pyrochlore and weberite structures, respectively, are reported. Structures of NH4CoCrF6, AlZnF5 ・ 2H2O, and GaMnF5 ・ 2H2O were refined using X-ray diffraction data from single crystals. The structures of MgIIAlIIIF5 ・H2O and NH4MgIIAlIIIF6 were refined from powder X-ray diffraction data. Magnetic susceptibility data indicates antiferromagnetic ordering in NH4CoIIVIIIF6 at 7 K but no ordering in NH4CoIICrIIIF6 down to 4.2 K. Electrical conductivity presumably due to protons was observed in MgAlF5 ・ (H2O)2.

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