scholarly journals Spin Crossover in Three Mononuclear Iron (III) Schiff Base Complexes

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 849 ◽  
Author(s):  
Ivan Nemec ◽  
Ingrid Svoboda ◽  
Radovan Herchel
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Schiff Base ◽  
Spin Crossover ◽  
Theoretical Calculations ◽  
Magnetic Behavior ◽  
Schiff Base Complexes ◽  
Mononuclear Iron ◽  
Mononuclear Complexes

The synthesis, crystal structure, and magnetic properties of three new mononuclear complexes [Fe(R-LA)(L1)](BPh4), where R-LA2− is a doubly deprotonated pentadentate Schiff base ligand and L1 is a monodentate benzimidazole or furopyridine ligand, are reported. Ligand- and anion-driven changes in crystal structures and magnetic behavior were investigated in terms of the magnetic susceptibility measurements and theoretical calculations.

scholarly journals Structural Evidence of Spin State Selection and Spin Crossover Behavior of Tripodal Schiff Base Complexes of tris(2-aminoethyl)amine and Related Tripodal Amines

2020 ◽  
Vol 6 (2) ◽  
pp. 28
Author(s):  
Greg Brewer
Keyword(s):  
Schiff Base ◽  
Spin State ◽  
Density Functional ◽  
Spin Crossover ◽  
Bimodal Distribution ◽  
Structural Features ◽  
Schiff Base Complexes ◽  
Mononuclear Iron ◽  
Experimental Values ◽  
State Selection

A review of the tripodal Schiff base (SB) complexes of tris(2-aminoethyl)amine, Nap(CH2CH 2NH2)3 (tren), and a few closely related tripodal amines with Cr(II), Mn(III) (d4), Mn(II), Fe(III) (d5), Fe(II) (d6), and Co(II) (d7) is provided. Attention is focused on examination of key structural features, the M-Nimine, M-Namine, or M-O and M-Nap bond distances and Nimine-M-N(O) bite and C-Nap-C angles and how these values correlate with spin state selection and spin crossover (SCO) behavior. A comparison of these experimental values with density functional theory calculated values is also given. The greatest number, 132, of complexes is observed with cationic mononuclear iron(II) in a N6 donor set, Fe(II)N6. The dominance of two spin states, high spin (HS) and low spin (LS), in these systems is indicated by the bimodal distribution of histogram plots of Fe(II)-Nimine and Fe(II)-Nazole/pyridine bond distances and of Nimine–Fe(II)-Nazole/pyridine and C-Nap-C bond angles. The values of the two maxima, corresponding to LS and HS states, in each of these histograms agree closely with the theoretical values. The iron(II)-Nimine and iron(II)-Nazole/pyridine bond distances correlate well for these complexes. Examples of SCO complexes of this type are tabulated and a few of the 20 examples are discussed that exhibit interesting features. There are only a few mononuclear iron(III) cationic complexes and one is SCO. In addition, a significant number of supramolecular complexes of these ligands that exhibit SCO, intervalence, and chiral recognition are discussed. A summary is made regarding the current state of this area of research and possible new avenues to explore based on analysis of the present data.

scholarly journals Impact of Substituent Variation on the Presence of Thermal Spin Crossover in a Series of Mononuclear Iron(III) Schiff Base Complexes with Terminal Pseudohalido Co-ligands

2017 ◽  
Vol 24 (20) ◽  
pp. 5191-5203 ◽  
Author(s):  
Lukáš Pogány ◽  
Barbora Brachňaková ◽  
Ján Moncol ◽  
Ján Pavlik ◽  
Ivan Nemec ◽  
...  
Keyword(s):  
Schiff Base ◽  
Spin Crossover ◽  
Schiff Base Complexes ◽  
Mononuclear Iron

Exchange Interaction in a Dinuclear Iron(III) Complex of a Heptadentate Schiff Base: Synthesis, Crystal Structure and Magnetic Properties

2005 ◽  
Vol 60 (7) ◽  
pp. 727-731 ◽  
Author(s):  
C. T. Zeyrek ◽  
A. Elmali ◽  
Y. Elerman
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Schiff Base ◽  
Exchange Interaction ◽  
Hamiltonian Operator ◽  
Antiferromagnetic Coupling ◽  
Iron Ions ◽  
Spin Hamiltonian ◽  
Dinuclear Iron

Synthesis, crystallographic characterization and magnetic properties of the new dinuclear iron(III) complex Fe2L(OCH3)Cl2 (L=1,3-bis[N-(3,5-dichloro-2-hydroxybenzylidene)-2-aminoethyl]-2-(3,5- dichlo ro-2-hydroxyphenyl)imidazolidine) are reported. The structure consists of dinuclear units. The two iron(III) atoms are asymmetrically bridged by a phenoxo and a methoxo group. The iron(III) centers are separated by 3.133(2) Å . The Magnetic susceptibility of the complex was measured over the range 5 - 298 K and the observed data were successfully simulated by the equation based on the spin-Hamiltonian operator H = −JS⃗1.S⃗2. Magnetic susceptibility measurements indicate very weak antiferromagnetic coupling between the iron ions with J = −10.8 cm−1 and g = 2.0.

Synthesis, crystal structure and magnetic properties of quasi-linear tetranuclear copper(II) Schiff base complexes formed by covalent linkage of asymmetrically dibridged dicopper(II) units

2004 ◽  
Vol 357 (4) ◽  
pp. 1077-1082 ◽  
Author(s):  
Arindam Mukherjee ◽  
Manas K. Saha ◽  
Indranil Rudra ◽  
Suryanarayanasastry Ramasesha ◽  
Munirathinam Nethaji ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Schiff Base ◽  
Schiff Base Complexes ◽  
Covalent Linkage

Low-spin iron(III) Schiff-base complexes with symmetric hexadentate ligands: Synthesis, crystal structure, spectroscopic and magnetic properties

Polyhedron ◽  
2006 ◽  
Vol 25 (7) ◽  
pp. 1646-1654 ◽  
Author(s):  
Ramu Kannappan ◽  
Stefania Tanase ◽  
Ilpo Mutikainen ◽  
Urho Turpeinen ◽  
Jan Reedijk
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Schiff Base ◽  
Schiff Base Complexes

Anion-driven supramolecular modulation of spin-crossover properties in mononuclear iron(iii) Schiff-base complexes

2021 ◽  
Author(s):  
Zong-Mei Yu ◽  
Sheng-Ze Zhao ◽  
Yu-Ting Wang ◽  
Peng-Yu Xu ◽  
Chun-Yan Qin ◽  
...  
Keyword(s):  
Schiff Base ◽  
Spin Crossover ◽  
Supramolecular Structures ◽  
Schiff Base Complexes ◽  
Mononuclear Iron

A series of iron(iii) complexes [Fe(5-F-sal-N-1,4,7,10)]Y (Y = anion) have been studied in detail which gave the understanding of the influence of anion effects and intermolecular supramolecular structures on their spin crossover properties.

Spin crossover and high spin electroneutral mononuclear iron(iii) Schiff base complexes involving terminal pseudohalido ligands

2015 ◽  
Vol 39 (1) ◽  
pp. 508-519 ◽  
Author(s):  
Petra Masárová ◽  
Pavel Zoufalý ◽  
Ján Moncol ◽  
Ivan Nemec ◽  
Ján Pavlik ◽  
...  
Keyword(s):  
Schiff Base ◽  
High Spin ◽  
Spin State ◽  
Spin Crossover ◽  
High Spin State ◽  
Schiff Base Complexes ◽  
Mononuclear Iron ◽  
State Behaviour

Six new Schiff-base complexes (1–6) with pseudohalido terminal ligands exhibits spin crossover or high spin state behaviour.

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