Dinuclear Zn Complex: Phenoxyl Radical Formation Driven by Superoxide Coordination

Abstract The dinuclear zinc complex Zn2L2 (HL=2‐{[[di(2‐pyridyl)methyl](methyl)amino]methyl}phenol) has been synthesized and isolated as colorless crystals. The interaction of the compound with superoxide in anhydrous organic solvents has been evaluated by CV, stopped‐flow Uv‐vis, EPR and ESI‐MS suggesting the binding and the activation of the coordinated superoxide, thanks to the Lewis acidity of the Zn(II) centers. The results obtained in this study highlight the formation of a Zn2L2−O2.− intermediate and a metastable phenoxyl‐radical driven by the coordinated superoxide

Supplementary data for article: Lippert, R.; Shubina, T. E.; Vojnovic, S.; Pavic, A.; Veselinovic, J.; Nikodinovic-Runic, J.; Stankovic, N.; Ivanović-Burmazović, I. Redox Behavior and Biological Properties of Ferrocene Bearing Porphyrins. Journal of Inorganic Biochemistry 2017, 171, 76–89. https://doi.org/10.1016/j.jinorgbio.2017.03.002

Supplementary material for: [https://doi.org/10.1016/j.jinorgbio.2017.03.002]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2467

Targeting the superoxide/nitric oxide ratio by L-arginine and SOD mimic in diabetic rat skin

AbstractSetting the correct ratio of superoxide anion (O2•-) and nitric oxide (•NO) radicals seems to be crucial in restoring disrupted redox signaling in diabetic skin and improvement of •NO physiological action for prevention and treatment of skin injuries in diabetes. In this study we examined the effects of L-arginine and manganese(II)-pentaazamacrocyclic superoxide dismutase (SOD) mimic – M40403 in diabetic rat skin. Following induction of diabetes by alloxan (blood glucose level ≥12 mMol l −1) non-diabetic and diabetic male Mill Hill hybrid hooded rats were divided into three subgroups: (i) control, and receiving: (ii) L-arginine, (iii) M40403. Treatment of diabetic animals started after diabetes induction and lasted for 7 days. Compared to control, lower cutaneous immuno-expression of endothelial NO synthase (eNOS), heme oxygenase 1 (HO1), manganese SOD (MnSOD) and glutathione peroxidase (GSH-Px), in parallel with increased NFE2-related factor 2 (Nrf2) and nitrotyrosine levels characterized diabeti..

Supplementary data for article: Lippert, R.; Shubina, T. E.; Vojnovic, S.; Pavic, A.; Veselinovic, J.; Nikodinovic-Runic, J.; Stankovic, N.; Ivanović-Burmazović, I. Redox Behavior and Biological Properties of Ferrocene Bearing Porphyrins. Journal of Inorganic Biochemistry 2017, 171, 76–89. https://doi.org/10.1016/j.jinorgbio.2017.03.002

Supplementary material for: [https://doi.org/10.1016/j.jinorgbio.2017.03.002]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2467

Synthesis and structural characterisation of unprecedented primary N -nitrosamines coordinated to iridium(IV)

The redox chemistry of the N-nitrosamine complexes [IrCl5(RN(H)NO)]2- (R = benzyl or n-butyl) was studied in detail. One-electron oxidations at around 200 mV vs. ferrocene/ferrocenium were reversible in cyclic voltammograms. UV-vis spectroelectrochemistry reveals spectra characteristic of IrIV species but also partial decomposition of the oxidised species [IrIVCl5(RN(H)NO)]- on this timescale (minutes). Detailed studies on chemically oxidised solutions of the parent IrIII complexes gave evidence for paramagnetic IrIV from NMR spectra. Final products of the decomposition were the corresponding alcohols and presumably [IrIIICl5(L)]2- (L = N2, solvent, amine) complexes. Similar decomposition reactions of acidic DMSO solutions of [IrCl5(RN(H)NO)]2-revealed that this combination produces the so-called "activated" DMSO (Me2S+-O- or Me2S+-OE, with "E" being an electrophile) which oxidises the parent IrIII complexes. Finally, with the very reactive purple IrIV compound (PPh4)[IrCl5(BnN(H)NO)], the first primary N-nitrosamine coordinated to [IrIVCl5]- was isolated and characterised by UV-vis absorption, FTIR, NMR spectroscopy, ultra-high resolution electrospray mass spectrometry (UHR-ESI-MS) and iridium L3 X-ray absorption near-edge spectroscopy (XANES).Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Carbon-rich cyclopentadienyl ruthenium allenylidene complexes

Ruthenium allenylidene complexes with carbon-rich polyaromatic moieties have been synthesized by using [RuCl(η5-C5H5)(PPh3)2] (η5-C5H5 = cyclopentadienyl) as a precursor and the propargyl alcohols 10-ethynyl-10-hydroxyanthracen-9-one (ACO), 13-ethynyl-13-hydroxypentacen-6-one (PCO), 1-phenyl-1-(pyren-1-yl)prop-2-yn-1-ol (PyrPh), 9-ethynyl-9H-fluoren-9-ol (FN) and 6-ethynyl-6H-benzo[cd]pyren-6-ol (BPyr) as ligands. The resulting cationic allenylidene complexes, [Ru(η5-C5H5)([double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash](AO))(PPh3)2]PF6 (1), [Ru(η5-C5H5)([double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash](PCO))(PPh3)2]PF6 (2), [Ru(η5-C5H5)([double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash](PyrPh))(PPh3)2]PF6 (3), [Ru(η5-C5H5)([double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash](FN))(PPh3)2]PF6 (4), and [Ru(η5-C5H5)([double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash](BPyr))(PPh3)2]PF6 (5) show interesting intermolecular π-interactions in the solid-state structure as well as solution state complexation with pyrene (documented by Job's plots experiments). CV data indicate possible Ru(II)/Ru(III) oxidation, as well as the potential reduction of the carbon-rich allenylidene moiety

Thermal analysis in structural characterization of hydrazone ligands and their complexes

Results of our research on synthesis and characterization of complexes with acylhydrazone derivatives are described in this review paper. Structural characterization of newly synthesized complexes by thermal analysis (TG, DTA, DSC) is particularly emphasized in this paper. Thermal analysis enabled us to Study not only structural changes of substances during thermal treatment, but also the mode of coordination and degree of deprotonation of acylhydrazones, as well as geometry of the coordination sphere of complexes, the structure of which had not been determined by X-ray analysis. Topics in this paper are as follows: complexes of dioxomolybdenum(VI) with tridentate hydrazones, usnic acid derivatives and their Cu(II) complexes, as well as transition metal complexes with 2,6-diacetylpyridine bis(hydrazones)

Pentagonal-bipyramidal Mn(II) and Zn(II) complexes with 2',2'''-(2,6-pyridindiyldi-ethylidene)dioxamohydrazide

[Mn(H(2)dapsox)Cl(H2O)](ClH2O)-H-. (1) and [Zn(H(2)dapsox)(H2O)(2)](Cl2H2O)-H-. (2) were synthesized from 2,6-diacetylpyridine (dap), oxamic acid hydrazide (sox) and MnCl(2)(.)4H(2)O or ZnCl(2)(.)2H(2)O in 1:2:1 molar ratio, employing a template approach. Based on elemental analyses, molar conductivity and magnetic susceptibility data, IR, H-1 and C-13 NMR and EA spectra, as well as thermal analyses (DSC and TG), a pentagonal-bipyramidal (PBP) geometry for the complexes was determined. Symmetrically coordinated 2,2"'-(2,6-pyridindiyldiethylidene)dioxamohydrazide (H(2)dapsox) is located as a pentadentate ligand in the equatorial plane. The stability of the 3d metal complexes having the PBP geometry is discussed. It was found that Co(II) and Mn(II) produce the most stable complexes of this type, while the Zn(II) complex of the same geometry is much less stable