High-Spin Metal Complexes Containing a Ferromagnetically Coupled Tris(semiquinone) Ligand

2002 ◽  
Vol 41 (5) ◽  
pp. 1086-1092 ◽  
Author(s):  
Andrea Caneschi ◽  
Andrea Dei ◽  
Christopher P. Mussari ◽  
David A. Shultz ◽  
Lorenzo Sorace ◽  
...  
Keyword(s):  
Metal Complexes ◽  
High Spin

High-spin enforcement in first-row metal complexes of a constrained polyaromatic ligand: synthesis, structure, and properties

2018 ◽  
Vol 42 (23) ◽  
pp. 18667-18677 ◽  
Author(s):  
Lizhu Chen ◽  
Hunter A. Dulaney ◽  
Branford O. Wilkins ◽  
Sarah Farmer ◽  
Yanbing Zhang ◽  
...  
Keyword(s):  
Coordination Chemistry ◽  
Transition Metals ◽  
Metal Complexes ◽  
High Spin ◽  
Structure And Properties ◽  
Polypyridyl Ligand ◽  
Ligand Synthesis

The coordination chemistry of a rigid tetradentate polypyridyl ligand has been developed with first-row transition metals Mn(ii), Fe(ii), Co(ii), Ni(ii), and Zn(ii).

Metal complexes of 1,10-phenanthroline derivatives. XIV. Complexes of 1,10-Phenanthrolin-2-yl(pyridin-2-yl)amine

1984 ◽  
Vol 37 (2) ◽  
pp. 281 ◽  
Author(s):  
AS Abushamleh ◽  
HA Goodwin ◽  
CG Benson ◽  
GJ Long
Keyword(s):  
Metal Complexes ◽  
Spectral Data ◽  
High Spin ◽  
Metal Ion ◽  
Chelate Ring ◽  
Chelating Agent ◽  
Membered Chelate Ring

1,10-Phenanthrolin-2-yl(pyridin-2-yl)amine has been prepared in low yield from 2-chloro-1,10- phenanthroline and pyridin-2-amine. The molecule coordinates as a tridentate chelating agent of the ter-imine type and produces low-spin complexes with iron(II) in both its neutral and anionic forms. The bis(ligand) cobalt(II) complex is high-spin. Although the ligand provides a slightly weaker field than terpyridine, electronic and Mossbauer spectral data indicate a less distorted metal ion environment in its complexes, compared with those of terpyridine. This is correlated with the presence of the six-membered chelate ring.

Übergangsmetallkomplexe mit Schwefelliganden, CI*. Synthese und Struktur von N2H5[Fe(N2H4)(S2C6H4)2] · 1,33N2H4 / Transition Metal Complexes with Sulfur Ligands, Cl*. Synthesis and Structure of N2H5[Fe(N2H4)(S2C6H4)2] · 1,33N2H4

1994 ◽  
Vol 49 (5) ◽  
pp. 660-664 ◽  
Author(s):  
Dieter Sellmann ◽  
Helge Friedrich ◽  
Falk Knoch
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Structure Analysis ◽  
High Spin ◽  
Transition Metal Complexes ◽  
X Ray ◽  
Labile N

Attempts to coordinate N2H4 to [Fe(S2C6H4)2] fragments lead to N2H5[Fe(N2H4)(S2C6H4)2], which crystallizes from MeOH/N2H4 solutions as the solvate [(N2H5){Fe(N2H4)(S2C6H4)2} · 1,33 N2H4]. 1, and has been characterized by X-ray structure analysis. 1 contains three discrete N2H5+ cations, four N2H4 solvate molecules and three independent [Fe(N2H4)(S2C6H4)2]- anions which are connected via an extended network of N-H ··· N and N-H ··· S bridges. N2H5[Fe(N2H4)(S2ChH4)2] and 1 contain high-spin Fe(III) centers and labile N2H4 ligands.

Progress and design challenges for high-spin molecules

2010 ◽  
Vol 83 (1) ◽  
pp. 141-149 ◽  
Author(s):  
Martin T. Lemaire
Keyword(s):  
Free Radical ◽  
Metal Complexes ◽  
High Spin ◽  
Critical Review ◽  
Mixed Valence ◽  
Double Exchange ◽  
Stable Free Radical ◽  
The Past ◽  
Molecule Design ◽  
Design Challenges

In this short critical review, selected examples of current (within the past two years) synthetic efforts toward the construction of high-spin molecules are explored, including the use of metal complexes containing stable free radical ligands, lanthanide or actinide complexes, and other coordination clusters, or a completely different approach, taking advantage of non-Heisenberg exchange in fully delocalized mixed-valence complexes (spin-dependent delocalization, SDD, or double exchange). A description of reported work in this regard is followed by a brief general discussion that highlights what the future may hold for high-spin molecule design.

Metal complexes of 1,10-Phenanthroline derivatives. IV. Complexes of 1,10-Phenanthroline-2-carboxamide

1972 ◽  
Vol 25 (1) ◽  
pp. 37 ◽  
Author(s):  
HA Goodwin ◽  
FE Smith
Keyword(s):  
Oxygen Atom ◽  
Metal Complexes ◽  
High Spin ◽  
Chelating Agent ◽  
Weak Field ◽  
Amide Group ◽  
Magnetic Data ◽  
Iron Cobalt ◽  
Cobalt Nickel ◽  
Bivalent Iron

Complexes of the tridentate chelating agent 1,l0-phenanthroline-2- carboxamide, with bivalent iron, cobalt, nickel, and copper are described. Bis-ligand, six-coordinate complexes were obtained with all metals. A series of mono-ligand complexes, which are also believed to be six-coordinate, was also obtained. Infrared evidence indicates that the amide group is bound through the oxygen atom. Electronic spectral and magnetic data indicate that the ligand produces a relatively weak field and the iron complexes are high-spin. The tris-ligand iron(11) complex of pyridine-2-carboxamide is also described. This too is high-spin, although the bidentate amide apparently produces a slightly stronger field than the tridentate.

scholarly journals Transition metal complexes with thiosemicarbazide-based ligands, part 47: Synthesis, physicochemical and voltammetric characterization of iron(III) complexes with pyridoxal semi-, thiosemi- and S-meth

2003 ◽  
Vol 68 (12) ◽  
pp. 929-942 ◽  
Author(s):  
Violeta Jevtovic ◽  
Ljiljana Jovanovic ◽  
Vukadin Leovac ◽  
Luka Bjelica
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
High Spin ◽  
Transition Metal Complexes ◽  
Elemental Analysis ◽  
Solution Equilibria ◽  
Electrode Processes ◽  
Voltammetric Study

The reaction of warm EtOH solutions of FeX3.nH2O (X=Cl, NO3) with tridentate ONX (X=O, S, N) pyridoxal semi-, thiosemi- and S-methylisothiosemicabazones (H2L1, H2L2, H2L3, respectively) yielded high-spin octahedral mono- and bis(ligand) complexes of the formula [Fe(H2L1-3)Cl2(H2O)]Cl,[Fe(HL1,2)2]Cl.nH2O and [Fe(H2L3)(HL3)]NO3)2.H2O. The compounds were characterized by elemental analysis, conductometric and magnetochemical measurements, IR and UV-Vis spectra. Besides, a detailed voltammetric study of the complexes was carried out in DMF solution in the presence of several supporting electrolytes, to characterize the nature of the electrode processes and solution equilibria.

scholarly journals Ferromagnetism in polynuclear systems based on non-linear [MnII2MnIII] building blocks

2016 ◽  
Vol 3 (10) ◽  
pp. 1272-1279 ◽  
Author(s):  
Jordi Cirera ◽  
Yuan Jiang ◽  
Lei Qin ◽  
Yan-Zhen Zheng ◽  
Guanghua Li ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
High Spin ◽  
Transition Metal Complexes ◽  
Building Blocks ◽  
Bridging Ligands ◽  
Non Linear ◽  
Important Challenge ◽  
Ferromagnetic Interactions

Design of new polynuclear transition metal complexes showing ferromagnetic interactions to achieve high spin values is an important challenge due to the scarcity of bridging ligands that provide such coupling.

Kohn–Sham calculations of NMR shifts for paramagnetic 3d metal complexes: protocols, delocalization error, and the curious amide proton shifts of a high-spin iron(ii) macrocycle complex

2016 ◽  
Vol 18 (31) ◽  
pp. 21051-21068 ◽  
Author(s):  
Bob Martin ◽  
Jochen Autschbach
Keyword(s):  
Metal Complexes ◽  
Spin Density ◽  
High Spin ◽  
Chemical Shifts ◽  
Amide Proton ◽  
3D Metal Complexes ◽  
High Spin Iron

Ligand chemical shifts (pNMR shifts) are analyzed using DFT. A large difference in the amide proton shifts of a high-spin Fe(ii) complex arises from O → Fe dative bonding which only transfers β spin density to the metal.

Metal complexes of 1,10-Phenanthroline derivatives. VII. Complexes of 1,10-Phenanthroline-2-carbaldehyde hydrazones

1974 ◽  
Vol 27 (5) ◽  
pp. 965 ◽  
Author(s):  
HA Goodwin ◽  
DW Mather
Keyword(s):  
Field Strength ◽  
Metal Complexes ◽  
High Spin ◽  
Spin State ◽  
Spin Transition ◽  
Pronounced Change ◽  
Temperature Range ◽  
Spin Pairing ◽  
Bivalent Iron ◽  
Experimental Temperature Range

A series of substituted hydrazones derived from 1,l0-phenanthroline-2-carbaldehyde and their bis-ligand complexes with bivalent iron and nickel are described. The hydrazones show a gradation in field strength and this is reflected in the spin-state of the iron complexes. The methylhydrazone complex is essentially low-spin over the temperature range 83-363 K but the presence of some spin-free species at high temperatures is evident. Within the same range the dimethylhydrazone complex is essentially high-spin but undergoes significant spin-pairing and the phenylhydrazone complex displays a complete 5T2 → 1A1 spin transition. This transition is very sharp, resulting in a pronounced change in the magnetism, and colour, of the complex within a few degrees. Complexes of the 2-pyridylhydrazone, the methylphenylhydrazone and the diphenylhydrazone are high-spin over the entire experimental temperature range.

Sign in / Sign up

Export Citation Format

Share Document