Ferromagnetic Coupling in a Mixed-Valence Hexavanadate Core: Quantum-Chemical Forecast

2007 ◽  
Vol 2007 (27) ◽  
pp. 4317-4325 ◽  
Author(s):  
Ekaterina M. Zueva ◽  
Serguei A. Borshch ◽  
Maria M. Petrova ◽  
Henry Chermette ◽  
Andrey M. Kuznetsov
Keyword(s):  
Quantum Chemical ◽  
Mixed Valence ◽  
Ferromagnetic Coupling

scholarly journals Quantum-chemical insights into mixed-valence systems: within and beyond the Robin–Day scheme

2014 ◽  
Vol 43 (14) ◽  
pp. 5067-5088 ◽  
Author(s):  
M. Parthey ◽  
M. Kaupp
Keyword(s):  
Transition Metal ◽  
Quantum Chemical ◽  
Mixed Valence ◽  
Chemical Methods ◽  
Quantum Chemical Methods

The application of quantum-chemical methods to both organic and transition-metal mixed-valence systems is reviewed, with particular emphasis on how to describe correctly delocalisation vs. localisation near the borderline between Robin–Day classes II and III.

A Reliable Quantum-Chemical Protocol for the Characterization of Organic Mixed-Valence Compounds

2009 ◽  
Vol 131 (44) ◽  
pp. 16292-16302 ◽  
Author(s):  
Manuel Renz ◽  
Kolja Theilacker ◽  
Christoph Lambert ◽  
Martin Kaupp
Keyword(s):  
Quantum Chemical ◽  
Mixed Valence ◽  
Mixed Valence Compounds

scholarly journals Self-assembly of a mixed-valence FeII–FeIII tetranuclear star

2018 ◽  
Vol 47 (21) ◽  
pp. 7118-7122 ◽  
Author(s):  
Darunee Sertphon ◽  
Phimphaka Harding ◽  
Keith S. Murray ◽  
Boujemaa Moubaraki ◽  
Nicholas F. Chilton ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Single Molecule ◽  
Self Assembly ◽  
Mixed Valence ◽  
Ferromagnetic Coupling ◽  
Coupling Field ◽  
Self Assembled

A self-assembled mixed-valence FeII–FeIII tetranuclear star is reported that shows ferromagnetic coupling, field-induced single molecule magnetism and strong magnetic anisotropy at the peripheral FeII centres.

scholarly journals One-Pot Self-Assembly of Dinuclear, Tetranuclear, and H-Bonding-Directed Polynuclear Cobalt(II), Cobalt(III), and Mixed-Valence Co(II)/Co(III) Complexes of Schiff Base Ligands with Incomplete Double Cubane Core

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5425
Author(s):  
Santokh S. Tandon ◽  
Neil Patel ◽  
Scott D. Bunge ◽  
Esther C. Wang ◽  
Rachel Thompson ◽  
...  
Keyword(s):  
Self Assembly ◽  
Mixed Valence ◽  
Coordination Complexes ◽  
Magnetic Interactions ◽  
Single Atom ◽  
Ferromagnetic Coupling ◽  
Schiff Base Ligands ◽  
One Pot ◽  
Bulk Magnetization ◽  
Dinuclear Unit

The reaction of 2,6-diformyl-4-methylphenol (DFMF) with 1-amino-2-propanol (AP) and tris(hydroxymethyl)aminomethane (THMAM) was investigated in the presence of Cobalt(II) salts, (X = ClO4−, CH3CO2−, Cl−, NO3−), sodium azide (NaN3), and triethylamine (TEA). In one pot, the variation in Cobalt(II) salt results in the self-assembly of dinuclear, tetranuclear, and H-bonding-directed polynuclear coordination complexes of Cobalt(III), Cobalt(II), and mixed-valence CoIICoIII: [Co2III(H2L−1)2(AP−1)(N3)](ClO4)2 (1), [Co4(H2L−1)2(µ3-1,1,1-N3)2(µ-1,1-N3)2Cl2(CH3OH)2]·4CH3OH (2), [Co2IICo2III(HL−2)2(µ-CH3CO2)2(µ3-OH)2](NO3)2·2CH3CH2OH (3), and [Co2IICo2III (H2L12−)2(THMAM−1)2](NO3)4 (4). In 1, two cobalt(III) ions are connected via three single atom bridges; two from deprotonated ethanolic oxygen atoms in the side arms of the ligands and one from the1-amino-2-propanol moiety forming a dinuclear unit with a very short (2.5430(11) Å) Co-Co intermetallic separation with a coordination number of 7, a rare feature for cobalt(III). In 2, two cobalt(II) ions in a dinuclear unit are bridged through phenoxide O and μ3-1,1,1-N3 azido bridges, and the two dinuclear units are interconnected by two μ-1,1-N3 and two μ3-1,1,1-N3 azido bridges generating tetranuclear cationic [Co4(H2L−1)2(µ3-1,1,1-N3)2(µ-1,1-N3)2Cl2(CH3OH)2]2+ units with an incomplete double cubane core, which grow into polynuclear 1D-single chains along the a-axis through H-bonding. In 3, HL2− holds mixed-valent Co(II)/Co(III) ions in a dinuclear unit bridged via phenoxide O, μ-1,3-CH3CO2−, and μ3-OH− bridges, and the dinuclear units are interconnected through two deprotonated ethanolic O in the side arms of the ligands and two μ3-OH− bridges generating cationic tetranuclear [Co2IICo2III(HL−2)2(µ-CH3CO2)2(µ3-OH)2]2+ units with an incomplete double cubane core. In 4, H2L1−2 holds mixed-valent Co(II)/Co(III) ions in dinuclear units which dimerize through two ethanolic O (μ-RO−) in the side arms of the ligands and two ethanolic O (μ3-RO−) of THMAM bridges producing centrosymmetric cationic tetranuclear [Co2IICo2III (H2L1−2)2(THMAM−1)2]4+ units which grow into 2D-sheets along the bc-axis through a network of H-bonding. Bulk magnetization measurements on 2 demonstrate that the magnetic interactions are completely dominated by an overall ferromagnetic coupling occurring between Co(II) ions.

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