scholarly journals Correlation between Supramolecular Connectivity and Magnetic Behaviour of [FeIII(5-X-qsal)2]+-Based Salts Prone to Exhibit SCO Transition

2021 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Bruno J. C. Vieira ◽  
Laura C. J. Pereira ◽  
Vasco da Gama ◽  
Isabel C. Santos ◽  
Ana C. Cerdeira ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Spin Crossover ◽  
Structural Features ◽  
Magnetic Behaviour ◽  
Extensive Study ◽  
Solvent Molecules ◽  
New Compounds ◽  
The Relationship ◽  
Structure Properties

We present an extensive study to determine the relationship between structural features of spin crossover (SCO) systems based on N-(8-quinolyl)salicylaldimine (qsal) ligand derivatives and their magnetic properties. Thirteen new compounds with general formula [FeIII(5-X-qsal)2]+ (X = H, F, Cl, Br and I) coupled to Cl−, ClO4−, SCN−, PF6−, BF4− and BPh4− anions were prepared and magnetically characterized. The structure/properties correlations observed in these compounds were compared to those of salts with the same [FeIII(qsal-X)2]+ cations previously reported in the literature. These cations favour the LS configuration in compounds with the weakest connectivity. As connectivity increases most of them present HS states at room temperature and structures may be described as arrangements of parallel layers of interacting cation dimers. All the compounds based on these cations undergoing complete SCO transitions within the 4–300 K temperature range have high intralayer connectivity. If, however, the interlayer connectivity becomes very strong they remain blocked in the HS or in the LS state. The SCO transition may be affected by the slightest change of solvent molecules content, disorder or even crystallinity of the sample and it remain difficult to predict which kind of ligand substituent should be selected to obtain compounds with the desired connectivity.

Substituted phenanthrolines and their metal chelates

1973 ◽  
Vol 26 (5) ◽  
pp. 951 ◽  
Author(s):  
EJ Halbert ◽  
CM Harris ◽  
E Sinn ◽  
GJ Sutton
Keyword(s):  
Magnetic Properties ◽  
High Spin ◽  
Copper Complex ◽  
Magnetic Moment ◽  
Room Temperature ◽  
Spin Crossover ◽  
Metal Chelates ◽  
One Step

Substituents at and adjacent to the nitrogen atoms in 2,2?-bipyridyl and 1,10-phenanthroline are most likely to cause drastic changes in the magnetic properties of complexes with these ligands. Complexes of the N-oxides (2,2?-bipyridine 1,1?-dioxide, and 1,10-phenanthroline 1- oxide) with copper, and of 2-substituted phen (substituent = Cl, CONH2) with iron(II) are investigated, and a new one-step reaction to convert phno into cphn is reported. The copper complex Cu(bpyo)Br2 shows antiferromagnetic interactions, but other complexes Cu(bpyo)X2 (X = Cl, NO3) with this ligand are magnetically normal, as are Cu(phno)Cl2 and Cu(phno)Br2. The complex [Fe(cphn)3] (ClO4)2 lies near the high spin-low spin crossover for iron(II), and its magnetic moment is normal at room temperature but falls with decreasing temperature. The dioxide of phen appears not to be formed by the literature method and no successful synthesis can be reported here.

scholarly journals The relationship between the strength of hydrogen bonding and spin crossover behaviour in a series of iron(iii) Schiff base complexes

2015 ◽  
Vol 44 (10) ◽  
pp. 4474-4484 ◽  
Author(s):  
Ivan Nemec ◽  
Radovan Herchel ◽  
Zdeněk Trávníček
Keyword(s):  
Hydrogen Bonding ◽  
Schiff Base ◽  
Spin Crossover ◽  
Schiff Base Complexes ◽  
Magnetic Spin ◽  
Solvent Molecules ◽  
The Relationship

The magnetic (spin crossover) properties of the complexes were tuned by the different crystal solvent molecules.

Towards direct correlations between spin-crossover and structural features in iron(II) complexes

2003 ◽  
Vol 59 (4) ◽  
pp. 479-486 ◽  
Author(s):  
Mathieu Marchivie ◽  
Philippe Guionneau ◽  
Jean-François Létard ◽  
Daniel Chasseau
Keyword(s):  
Crystal Structures ◽  
Room Temperature ◽  
Spin Crossover ◽  
Spin Transition ◽  
Intermolecular Hydrogen Bond ◽  
Structural Features ◽  
Gradual Transition ◽  
Hydrogen Bond Interaction ◽  
First Approximation ◽  
Two Phases

The [Fe(PM-BiA)2(NCS)2] complex, where PM is N-2-pyridylmethylene and BiA is 4-aminobiphenyl, crystallizes in two polymorphs. The two phases, denoted (I) and (II), undergo a spin-crossover when the sample is cooled and present distinct spin-transition features as (I) shows a very abrupt spin transition, while (II) exhibits a gradual transition. The two forms of the complex are used to investigate the correlations that exist between the spin-transition features and structural features. This article presents the crystal structures of polymorph (II) at room temperature (high spin) and at 120 K (low spin), including a comparison with those of polymorph (I). This study reveals that the packing, in a first approximation, is similar in both forms. In order to look at the crystal structures in more detail, a new angular parameter, denoted θNCS, as well as a particular type of intermolecular hydrogen-bond interaction, which involves the S atoms of the NCS ligands, are investigated. Interestingly, this angle and this intermolecular interaction can be directly connected to the cooperativity of the spin transition. Such a result is extended to all the SCO iron(II) complexes belonging to the same family of the general formula [Fe(PM-L)2(NCS)2].

Spin Crossover Meets Diarylethenes: Efficient Photoswitching of Magnetic Properties in Solution at Room Temperature

2013 ◽  
Vol 52 (19) ◽  
pp. 11585-11592 ◽  
Author(s):  
Magdalena Milek ◽  
Frank W. Heinemann ◽  
Marat M. Khusniyarov
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Spin Crossover

scholarly journals Engineering of magnetic properties in doped bismuth ferrite materials

2018 ◽  
Vol 218 ◽  
pp. 04027
Author(s):  
Hamdan Akbar Notonegoro ◽  
Bambang Soegijono ◽  
Isom Mudzakir
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Bismuth Ferrite ◽  
Magnetic Behaviour ◽  
Magnetic Saturation ◽  
Second Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystallite Structure

The engineering of magnetic behaviour of Li/Zn doped BiFeO3 had been done by synthesized a polycrystalline of BiFeO3, Bi0.96Li0.02FeO3, and Bi0.95Zn0.05FeO3. Investigation of crystallite structure and magnetic properties of the sampel had been done by X-ray diffraction and VSM analysis. At room temperature, the lithium and zinc doped bismuth ferrite has conducted a different magnetic behaviour. Within the ferromagnetic region, an increases of magnetic saturation or enlarger magnetic coercivity were identified. Doping lithium resulted in increasing magnetic saturation (Ms) and magnetic remanent (Mr), significantly. Meanwhile, doping zinc resulted in enlarger of magnetic coercivity coincide with the reveal of Bi20FeO40 as the second phase.

scholarly journals Magnetic and Structure Properties of CoPt-In₂O₃ Nanocomposite Films

2020 ◽  
pp. 431-438
Author(s):  
Liudmila E. Bykova ◽  
Victor G. Myagkov ◽  
Victor S. Zhigalov ◽  
Alexei A. Matsynin ◽  
Dmitry A. Velikanov ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Room Temperature ◽  
Vacuum Annealing ◽  
Nanocomposite Films ◽  
Film System ◽  
Temperature Range ◽  
Structural And Magnetic Properties ◽  
Average Size ◽  
Structure Properties

The structural and magnetic properties of CoPt-In₂O₃ nanocomposite films formed by vacuum annealing of the In/(Co3O4 + Pt)/MgO film system in the temperature range of 100–800 ◦C have been investigated. The synthesized nanocomposite films contain ferromagnetic CoPt grains with an average size of 5nm enclosed in an In2O3 matrix, and have a magnetization of 600 emu/cm3, and a coercivity of 150 Oe at room temperature. The initiation 200 ◦C and finishing 800 ◦C temperatures of synthesis were determined, as well as the change in the phase composition of the In/(Co3O4 + Pt)/MgO film during vacuum annealing

Reaction of chromocene with 1,2-ethanediamine and 2,2'-iminobisethanamine

1986 ◽  
Vol 51 (2) ◽  
pp. 314-317 ◽  
Author(s):  
Jaroslava Kalousová ◽  
Ludvík Beneš ◽  
Jiří Votinský
Keyword(s):  
Magnetic Properties ◽  
Ir Spectra ◽  
Room Temperature ◽  
Analogous Reaction ◽  
New Compounds

Reaction of chromocene with excess liquid 1,2-ethanediamine (en) or its vapours in vacuum at room temperature produces the compound [Cr(en)3](C5H5)2. Analogous reaction with 2,2'-iminobisethanamine (det) at 90 °C produces the compound [Cr(det)2](C5H5)2. The most likely bonding arrangement of the two new compounds has been suggested on the basis of results of measurements of their magnetic properties and IR spectra.

scholarly journals Disorder of lattice solvent molecules in the structure of hexaaqua(μ2-1,2,4,5-benzenetetracarboxylato)-bis(2,2’-dipyridylamine)dinickel(II) hexahydrate DMSO solvate

2007 ◽  
Vol 72 (8-9) ◽  
pp. 767-771 ◽  
Author(s):  
Dejan Poleti ◽  
Ljiljana Karanovic ◽  
Aleksandar Kremenovic ◽  
Jelena Rogan
Keyword(s):  
Diffraction Data ◽  
Binuclear Complex ◽  
Main Part ◽  
Room Temperature ◽  
Structural Features ◽  
X Ray Diffraction ◽  
X Ray ◽  
Triclinic System ◽  
Disordered Lattice ◽  
Solvent Molecules

The crystal structure of the complex [Ni2(btc)(dipya)2(H2O)6]?6H2O?DMSO (btc = tetra-anion of 1,2,4,5-benzenetetracarboxylic acid, dipya = 2,2?-dipyridylamine) was refined in the triclinic system, space group P1, using low temperature (170 K) X-ray diffraction data. The compound consists of binuclear complex entities and lattice solvent molecules making pseudo-layers parallel to the 101 plane and channels parallel to the b-axis. The observed structural features were compared with the previously reported results and formula [Ni2(btc)(dipya)2(H2O)6]?4H2O based on room temperature X-ray diffraction data. A possible arrangement of the disordered lattice solvent molecules located in the structural channels is described and discussed. It is concluded that the layout of these molecules is non-centrosymmetric, although the remaining and main part of the structure is centrosymmetric. .

Room Temperature Ferromagnetism in Gadolinium-doped Gallium Nitride

MRS Advances ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 159-164 ◽  
Author(s):  
Vishal G. Saravade ◽  
Cameron H. Ferguson ◽  
Amirhossein Ghods ◽  
Chuanle Zhou ◽  
Ian T. Ferguson
Keyword(s):  
Magnetic Properties ◽  
Gallium Nitride ◽  
Hall Effect ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Organic Ligand ◽  
Anomalous Hall Effect ◽  
Longitudinal Conductivity ◽  
Metallic Conduction ◽  
The Relationship

ABSTRACTAnomalous Hall effect was observed at room temperature in MOCVD-grown GaGdN from a (TMHD)3Gd source, which can contain oxygen in its organic ligand. GaN, and GaGdN grown using a Cp3Gd precursor which does not contain oxygen only showed the ordinary Hall effect. This indicates that oxygen could have a role in magnetic properties of GaGdN. The relationship between the anomalous Hall conductivity and longitudinal conductivity indicated that metallic conduction, hopping of carriers, and scattering-independent mechanisms are likely responsible for the ferromagnetism. However, this still requires further clarification.

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