Magnetic properties of some spin-crossover, high-spin, and low-spin cobalt(II) complexes with Schiff bases derived from 3-formylsalicylic acid

1984 ◽  
Vol 23 (5) ◽  
pp. 589-593 ◽  
Author(s):  
Jacqueline Zarembowitch ◽  
Olivier Kahn
Keyword(s):  
Magnetic Properties ◽  
Schiff Bases ◽  
High Spin ◽  
Spin Crossover

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.

Light- and Thermal-Induced Spin Crossover in {Fe(abpt)2[N(CN)2]2}. Synthesis, Structure, Magnetic Properties, and High-Spin ↔ Low-Spin Relaxation Studies

2001 ◽  
Vol 40 (16) ◽  
pp. 3986-3991 ◽  
Author(s):  
Nicolás Moliner ◽  
Ana B. Gaspar ◽  
M. Carmen Muñoz ◽  
Virginie Niel ◽  
Joan Cano ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
High Spin ◽  
Spin Relaxation ◽  
Spin Crossover ◽  
Relaxation Studies

scholarly journals Steric Quenching of Mn(III) Thermal Spin Crossover: Dilution of Spin Centers in Immobilized Solutions

2022 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Komala Pandurangan ◽  
Anthony B. Carter ◽  
Paulo N. Martinho ◽  
Brendan Gildea ◽  
Tibebe Lemma ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Structural Analysis ◽  
High Spin ◽  
Spin State ◽  
Spin Crossover ◽  
High Spin State ◽  
Spectroscopic Studies ◽  
Raman Spectroscopic ◽  
Spin Triplet ◽  
Structural And Magnetic Properties

Structural and magnetic properties of a new spin crossover complex [Mn(4,6-diOMe-sal2323)]+ in lattices with ClO4−, (1), NO3−, (2), BF4−, (3), CF3SO3−, (4), and Cl− (5) counterions are reported. Comparison with the magnetostructural properties of the C6, C12, C18 and C22 alkylated analogues of the ClO4− salt of [Mn(4,6-diOMe-sal2323)]+ demonstrates that alkylation effectively switches off the thermal spin crossover pathway and the amphiphilic complexes are all high spin. The spin crossover quenching in the amphiphiles is further probed by magnetic, structural and Raman spectroscopic studies of the PF6− salts of the C6, C12 and C18 complexes of a related complex [Mn(3-OMe-sal2323)]+ which confirm a preference for the high spin state in all cases. Structural analysis is used to rationalize the choice of the spin quintet form in the seven amphiphilic complexes and to highlight the non-accessibility of the smaller spin triplet form of the ion more generally in dilute environments. We suggest that lattice pressure is a requirement to stabilize the spin triplet form of Mn3+ as the low spin form is not known to exist in solution.

scholarly journals Magnetic Properties of Fe(II) Complexes of Cyclam Derivative with One p-Aminobenzyl Pendant Arm

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 366
Author(s):  
Bohuslav Drahoš ◽  
Peter Antal ◽  
Ivan Šalitroš ◽  
Radovan Herchel
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
High Spin ◽  
Spin Crossover ◽  
Crystal Packing ◽  
Theoretical Calculations ◽  
High Spin State ◽  
Magnetic Data ◽  
Pendant Arm ◽  
Pendant Arms

In order to prepare an Fe(II) spin crossover (SCO) complex that could be consequently modified to a bimetallic coordination compound that possesses another magnetic property of interest, a specially designed ligand L-NH2 (1-(4-aminobenzyl)-4,11-bis(pyridine-2-ylmethyl)- 1,4,8,11-tetraazacyclotetradecane) was prepared. This ligand consists of a macrocyclic cyclam part containing two 2-pyridylmethyl pendant arms (expecting SCO upon Fe(II) complexation) and one p-aminobenzyl pendant arm with an NH2 group. The presence of this group enables the consequent transformation to various functional groups for the selective complexation of other transition metals or lanthanides (providing the second property of interest). Furthermore, the performed theoretical calculations (TPSSh/def2-TZVP) predicted SCO behavior for the Fe(II) complex of L-NH2. Thus, Fe(II) complexes [Fe(L-NH2)](ClO4)2 (1) and [Fe(L-NH2)]Cl2·6H2O (2) were synthesized and thoroughly characterized. Based on the crystal structure of an isostructural analogous Ni(II) complex [Ni(L-NH2)]Cl2·6H2O (3), the coordination number six was confirmed with an octahedral coordination sphere and a cis-arrangement of the pyridine pendant arms. The measured magnetic data confirmed the high-spin behavior of both compounds with large magnetic anisotropy (D = 17.8 for 1 and 20.9 cm−1 for 2 complemented in both cases also with large rhombicity), though unfortunately without any indication of the SCO behavior with decreasing temperature. The lack of SCO can be ascribed to the crystal packing and/or the non-covalent intermolecular interactions stabilizing the high-spin state in the solid state.

Single crystal to single crystal transformation of spin-crossover coordination polymers from 3D frameworks to 2D layers

2021 ◽  
Vol 9 (15) ◽  
pp. 5082-5087
Author(s):  
Yu Gong ◽  
Wang-Kang Han ◽  
Hui-Shu Lu ◽  
Qing-Tao Hu ◽  
Huan Tu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Crystal ◽  
Coordination Polymers ◽  
Ligand Exchange ◽  
Spin Crossover ◽  
Metal Organic Frameworks ◽  
Crystal Transformation ◽  
Metal Organic

New Hofmann-type metal–organic frameworks display rare and complete ligand exchange induced single crystal to single crystal transformations from 3D frameworks to 2D layers, accompanied by magnetic properties transition from two-step SCO behavior to hysteretic SCO behavior.

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