A diamagnetic iron complex and its twisted sister – Structural evidence on partial spin state change in a crystalline iron complex

2021 ◽  
Author(s):  
Esko Salojärvi ◽  
Anssi Peuronen ◽  
Jani Moilanen ◽  
Hannu Huhtinen ◽  
Johan Linden ◽  
...  
Keyword(s):  
Spin State ◽  
Iron Complex ◽  
State Change ◽  
Tert Butyl ◽  
Fe Complex

We report here the syntheses of a diamagnetic Fe complex [Fe(HL)2] (1), prepared by reacting a redox non-innocent ligand precursor N,N’-bis(3,5-di-tert-butyl-2-hydroxy-phenyl)-1,2-phenylenediamine (H4L) with FeCl3, and its phenoxazine derivative [Fe(L’)2] (2),...

Can Spin State Change Slow Organometallic Reactions?

1995 ◽  
Vol 117 (47) ◽  
pp. 11745-11748 ◽  
Author(s):  
Jennifer L. Detrich ◽  
Olivia M. Reinaud ◽  
Arnold L. Rheingold ◽  
Klaus H. Theopold
Keyword(s):  
Spin State ◽  
State Change ◽  
Organometallic Reactions

scholarly journals Bilayer Thin Films That Combine Luminescent and Spin Crossover Properties for an Efficient and Reversible Fluorescence Switching

2019 ◽  
Vol 5 (2) ◽  
pp. 28 ◽  
Author(s):  
Alin-Ciprian Bas ◽  
Xavier Thompson ◽  
Lionel Salmon ◽  
Christophe Thibault ◽  
Gábor Molnár ◽  
...  
Keyword(s):  
Thin Films ◽  
Spin State ◽  
Spin Crossover ◽  
Uv Light ◽  
High Spin State ◽  
Iron Complex ◽  
Absorption Properties ◽  
Fluorescence Switching ◽  
Thermal Sensing ◽  
Vacuum Thermal Deposition

We report on the vacuum thermal deposition of bilayer thin films of the luminescent complex Ir(ppy)3, tris[2-phenylpyridinato-C2,N]iridium(III), and the spin crossover complex [Fe(HB(tz)3)2], bis[hydrotris(1,2,4-triazol-1-yl)borate]iron(II). Switching the spin state of iron ions from the low spin to the high spin state around 337 K leads to a reversible jump of the luminescence intensity, while the spectrum shape and the luminescence lifetime remain unchanged. The luminescence modulation occurs due to the different UV light absorption properties of the iron complex in the two spin states and its magnitude can therefore be precisely adjusted by varying the film thickness. These multilayer luminescence switches hold potential for micro- and nanoscale thermal sensing and imaging applications.

Kinetics and mechanism of dealkylation of coordinated isocyanide in Fe(PMe3)2(t-BuNC)3

2005 ◽  
Vol 83 (6-7) ◽  
pp. 626-633 ◽  
Author(s):  
Christine L Tennent ◽  
William D Jones
Keyword(s):  
Hydrogen Atom ◽  
Iron Complex ◽  
Kinetics And Mechanism ◽  
Zerovalent Iron ◽  
Mechanistic Studies ◽  
First Order ◽  
Tert Butyl ◽  
Preferential Formation ◽  
First Order Kinetics ◽  
Thermal Cleavage

The zerovalent iron complex Fe(PMe3)2(t-BuNC)3 undergoes thermal cleavage of the C—N bond to give Fe(PMe3)2(t-BuNC)2(H)(CN) and isobutylene. The reaction follows first order kinetics, and addition of the hydrogen-atom donor 1,4-cyclohexadiene leads to the preferential formation of isobutane rather than isobutylene. Mechanistic studies are consistent with a rate determining homolysis of the C—N bond, giving rise to tert-butyl radicals.Key words: iron, isocyanide, elimination, C—N cleavage.

In vitro digestion of caseinophosphopeptide–iron complex

2000 ◽  
Vol 67 (1) ◽  
pp. 125-129 ◽  
Author(s):  
NABIL AÎT-OUKHATAR ◽  
SAÏD BOUHALLAB ◽  
FRANÇOIS BUREAU ◽  
PIERRE ARHAN ◽  
JEAN-LOUIS MAUBOIS ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Digestive Enzymes ◽  
Brush Border Membrane ◽  
In Vitro Digestion ◽  
Iron Complex ◽  
Loop Model ◽  
Alkaline Ph ◽  
Fe Complex ◽  
Influence Of Ph

Caseins bind strongly to Fe by their phosphoseryl residues (Hegenauer et al. 1979; Brulé & Fauquant, 1982; Bouhallab et al. 1991; Emery, 1992) and keep it soluble at the alkaline pH of the duodenum (Manson & Annan, 1971; Bouhallab et al. 1991). It has been suggested that this strong binding prevents the release of free Fe during digestion and impairs its absorption (West, 1986; Hurrell, 1997), but in human studies hydrolysis by digestive enzymes to give low molecular mass peptides improves Fe absorption (Hurrell et al. 1988, 1989).β-Casein peptide 1–25 (β-CN(1–25)) is the phosphorylated N-terminal fragment of β-CN. Its molecular mass is 3124 Da and it contains four phosphoseryl residues that bind four Fe atoms and keep them soluble (Bouhallab et al. 1991).Preliminary results showed that binding Fe to β-CN(1–25) enhances its bioavailability in the rat (Aît-Oukhatar et al. 1997) and its absorption by the duodenal rat loop model (Pérès et al. 1997). We recently showed that the β- CN(1–25)–Fe complex is hydrolysed to a lesser extent than free β-CN(1–25) during duodenal digestion, and that the phosphorylated region of the peptide to which Fe is bound, β-CN(15–24), cannot be detected in the digestive lumen (our unpublished results).These previous studies did not examine the effect of luminal digestion that could release free inorganic Fe. We considered the possibility that Fe bound to β-CN(1–25) is not released in the digestive lumen, and that it reaches the absorbing surface of the small intestine brush border membrane as a complex. To test this hypothesis we examined in vitro the influence of pH and digestive enzymes on the dialysability of the β-CN(1–25)–Fe complex.

scholarly journals An iron(ii) spin-crossover metallacycle from a back-to-back bis-[dipyrazolylpyridine]

2015 ◽  
Vol 44 (20) ◽  
pp. 9417-9425 ◽  
Author(s):  
Laurence J. Kershaw Cook ◽  
Julie Fisher ◽  
Lindsay P. Harding ◽  
Malcolm A. Halcrow
Keyword(s):  
Spin State ◽  
Spin Crossover ◽  
Iron Complex ◽  
Conductivity Data ◽  
State Equilibrium ◽  
Dosy Nmr

Iron(ii) and zinc(ii) complexes of bis[2,6-di(pyrazol-1-yl)pyrid-4-yl]disulfide assemble into tetranuclear metallacycles according to ES-MS, DOSY NMR and conductivity data. The iron complex exhibits a thermal spin-state equilibrium in solution, which the iron centres appear to undergo independently of each other.

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