Synthesis, spectroscopic and structural characterization of mono- and bi-nuclear iron(II) complexes with 2,6-diacetylpyridine bis(acylhydrazones)

Bonardi, Alex; Carini, Clara; Merlo, Curzio; Pelizzi, Corrado; Pelizzi, Giancarlo; Tarasconi, Pieralberto; Vitali, Francesca; Cavatorta, F.

doi:10.1039/dt9900002771

Cited by 33 publications

(10 citation statements)

References 24 publications

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“…57 Fe Mössbauer spectroscopy was used to confirm the oxidation state of the Fe centers and the purity of the bulk samples for Fe‐containing derivatives. Mössbauer spectra of complexes 2 and 3 (Figure ) that were recorded at 80 K showed a unique sharp doublet defined by chemical shifts of 1.26 and 1.24 mm s −1 and quadrupole splittings of 2.91 and 1.11 mm s −1 , respectively, which is characteristic of high‐spin Fe II ions in a pentagonal bipyramid geometry . Their respective quadrupole splitting provides information on the nature of the ligands located in the apical positions, such that a smaller value is characteristic for the complex with two Cl ligands in the axial positions with respect to the ROH‐substituted species (R=H, Me) .…”

Section: Resultsmentioning

confidence: 99%

Pentagonal Bipyramid Fe^II Complexes: Robust Ising‐Spin Units towards Heteropolynuclear Nanomagnets

Bar

Gogoi

Pichon

et al. 2017

Chemistry A European J

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Pentagonal bipyramid Fe complexes have been investigated to evaluate their potential as Ising-spin building units for the preparation of heteropolynuclear complexes that are likely to behave as single-molecule magnets (SMMs). The considered monometallic complexes were prepared from the association of a divalent metal ion with pentadentate ligands that have a 2,6-diacetylpyridine bis(hydrazone) core (H L ). Their magnetic anisotropy was established by magnetometry to reveal their zero-field splitting (ZFS) parameter D, which ranged between -4 and -13 cm and was found to be modulated by the apical ligands (ROH versus Cl). The alteration of the D value by N-bound axial CN ligands, upon association with cyanometallates, was also assessed for heptacoordinated Fe as well as for related Ni and Co derivatives. In all cases, N-coordinated cyanide ligands led to large magnetic anisotropy (i.e., -8 to -18 cm for Fe and Ni, +33 cm for Co). Ab initio calculations were performed on three Fe complexes, which enabled one to rationalize the role of the ligand on the nature and magnitude of the magnetic anisotropy. Starting from the pre-existing heptacoordinated complexes, a series of pentanuclear compounds were obtained by reactions with paramagnetic [W(CN) ] . Magnetic studies revealed the occurrence of ferromagnetic interactions between the spin carriers in all the heterometallic systems. Field-induced slow magnetic relaxation was observed for mononuclear Fe complexes (U /k up to 53 K (37 cm ), τ =5×10 s), and SMM behavior was evidenced for a heteronuclear [Fe W ] derivative (U /k =35 K and τ =4.6 10 s), which confirmed that the parent complexes were robust Ising-type building units. High-field EPR spectroscopic investigation of the ZFS parameters for a Ni derivative is also reported.

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Section: Resultsmentioning

confidence: 99%

Pentagonal Bipyramid Fe^II Complexes: Robust Ising‐Spin Units towards Heteropolynuclear Nanomagnets

Bar

Gogoi

Pichon

et al. 2017

Chemistry A European J

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“…1(5) 95.1(5) 153. 6(4) 87.5(4) 101.7 (6) 87.9(7) 162.5 (5) 85.0(4) 106.0 (6) 76.5(4) 106.2 (5) 87.4(5)…”

Section: Fab Mass and Ir Spectramentioning

confidence: 99%

“…In the past few years the co-ordination properties of hydrazone ligands have extensively been investigated. [1][2][3][4][5][6][7][8][9] The development of this co-ordination chemistry is, in part, the result of the interesting donor systems which could result. Many ligands, mainly containing nitrogen donors in heterocyclic rings, but also in hydrazones, have been investigated in an attempt to predict their behaviour upon co-ordination.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical synthesis and structural characterisation of transition metal complexes with 2,6-bis(1-salicyloylhydrazonoethyl)pyridine, H4daps

Bermejo¹,

Fondo²,

González³

et al. 1999

J. Chem. Soc., Dalton Trans.

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“…The obtained values of the interatomic distances do not differ from those found in the complex diaqua-(2',2'''-(2,6-pyridinediyldiethylidyne)dioxamohydrazide)-iron(III) perchlorate hydrate [27,28]. In the Cambridge Structural Database 47 hits on structures of compounds of transition metals with ligands of this class are reported [29], mainly manganese or cobalt compounds, only 6 of them being iron compounds [27][28][29][30][31][32][33].…”

Section: Chemistrymentioning

confidence: 99%

Structure and Some Biological Properties of Fe(III) Complexes with Nitrogen-Containing Ligands

Bulhac¹,

Deseatnic-Ciloci²,

Боурош³

et al. 2016

ChemJMold

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Abstract. Four coordination compounds of iron(III) with ligands based on hydrazine and sulfadiazine: [Fe(dig) 2 -2,6-diacetylpyridine bis(isonicotinoylhydrazone) were synthesized. The spectroscopic and structure characterisation, as well as their biological properties, are presented. All tested coordination compounds, caused an inhibitory effect on the biosynthesis of hydrolases of the producer Aspergillus niger CNMN FD-10. The effect increased with the raise of the concentration from 5 mg/L to 15 mg/L. The complexes largely inhibited cellobiohydrolase and less-β-glucosidase. The inhibitory effect of the coordination compounds was quite similar in the case of endoglucanase and xylanase. Compound I, containing both chloride ions and dig, demonstrated a stronger inhibitory effect, while compound III, containing NO 3 -ions, showed the weakest inhibitory action.Keywords: iron complexes, nitrogen-containing ligands, structure, biological properties. IntroductionIn the modern microbiology, investigation of the effects of external factors on the physiology of microorganisms remains an actual issue. Such studies allow solving the practical problems and implementation of the new technologies in biology and medicine.The literature, in the last decades, denotes high physiological activity of the coordination compounds of transition metals on biological objects, including microorganisms [1][2][3][4][5][6][7][8][9][10][11][12][13]. Some authors note a signifi cant role of these compounds in the directed synthesis of biologically active substances from microalgae and cyanobacteria, fi lamentous fungi and yeast [1][2][3][4][5][6][7][8][9][10]12].Studies of the effects of coordination compounds on biosynthesis of extracellular hydrolases in fi lamentous fungi have been previously carried out [3][4][5][6][7]14]. It was established that these effects depend both on the properties of compounds (chemical composition, molecular structure, nature of the ligand and coordinated metal atom) and genus and species of the micromycetes strains, and specifi city of the synthesized enzymes [3][4][5][6][7]14]. Some coordination compounds exhibit a selective action on the components of the synthesized enzyme complex. Thus, by adding the molybdenum complex with valine -MoO 2 (acac) 2 Val (acac=acetylacetone, Val=valine) into the nutrient medium, the biosynthesis of β-glucosidase in micromycete Penicillium expansum CNMN FD 5C -producer of cellulases was enhanced by 69.4%, while the level of endoglucanase and cellobiohydrolase was not modifi ed. Study of the infl uence of (NH 4 ) 2 VO 2 Gly (Gly=glycine) on biosynthesis of cellulases of the same strain showed that the dioxovanadium complex increased the activity of all components of cellulase complex by 17.6-40.3% [14].The targeted application of the coordination compounds of 3d-elements as regulators of the microbial synthesis of bioactive substances requires accumulation of factual material on the nature of their infl uence on all phases of the development of microorganisms and also identifi ca...

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Synthesis, spectroscopic and structural characterization of mono- and bi-nuclear iron(II) complexes with 2,6-diacetylpyridine bis(acylhydrazones)

Cited by 33 publications

References 24 publications

Pentagonal Bipyramid Fe^II Complexes: Robust Ising‐Spin Units towards Heteropolynuclear Nanomagnets

Pentagonal Bipyramid Fe^II Complexes: Robust Ising‐Spin Units towards Heteropolynuclear Nanomagnets

Electrochemical synthesis and structural characterisation of transition metal complexes with 2,6-bis(1-salicyloylhydrazonoethyl)pyridine, H4daps

Structure and Some Biological Properties of Fe(III) Complexes with Nitrogen-Containing Ligands

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Synthesis, spectroscopic and structural characterization of mono- and bi-nuclear iron(II) complexes with 2,6-diacetylpyridine bis(acylhydrazones)

Cited by 33 publications

References 24 publications

Pentagonal Bipyramid FeII Complexes: Robust Ising‐Spin Units towards Heteropolynuclear Nanomagnets

Pentagonal Bipyramid FeII Complexes: Robust Ising‐Spin Units towards Heteropolynuclear Nanomagnets

Electrochemical synthesis and structural characterisation of transition metal complexes with 2,6-bis(1-salicyloylhydrazonoethyl)pyridine, H4daps

Structure and Some Biological Properties of Fe(III) Complexes with Nitrogen-Containing Ligands

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Pentagonal Bipyramid Fe^II Complexes: Robust Ising‐Spin Units towards Heteropolynuclear Nanomagnets

Pentagonal Bipyramid Fe^II Complexes: Robust Ising‐Spin Units towards Heteropolynuclear Nanomagnets