A [Mn] Defective Supertetrahedron T3 and Its Dimeric [Mn] Analogue.

The initial use of 2-(pyridin-2-yl)propane-1,3-diol (pypdH) in Mn cluster chemistry has afforded two new mixed-valence polynuclear Mn clusters, namely, [MnΟ(pypd)(hmp)(OCCMe)] () and [MnΟ(N)(pypd){(py)CO}(OCEt)] () (hmp = deprotonated 2-hydroxymethylpyridine; (py)CO = deprotonated gem-diol form of di-2-pyridyl ketone). Compound features a novel [Mn Mn(μ-O)(μ-O)(μ-OR)] structural core resembling a supertetrahedron T3, lacking two apexes, while complex has a [Mn Mn (μ-O)(μ-O)(μ-N)(μ-OR)(μ-OR)] core consisting of two [Mn] subunits related to and thus is a dimeric analogue of . Direct current (dc) magnetic susceptibility studies revealed the presence of dominant antiferromagentic exchange interactions between the Mn ions in complexes and and small ground state spin values for both compounds.

"Marriage" of Inorganic to Organic Chemistry as Motivation for a Theoretical Study of Chloroform Hydrolysis Mechanisms.

Incorporation of chlorides in coordination complexes, prepared by reactions in CHCl, stimulated MP2 and DFT studies of its complete hydrolysis mechanisms. In excellent agreement with previous experimental results, the most important mechanism for CHCl basic hydrolysis at room temperature is the radical one producing :CCl. The latter inserts into the H-O bond of HO yielding dichloromethanol ().

Solvatomorphism in a series of copper(II) complexes with the 5-phenylimidazole/perchlorate system as ligands.

In the course of an investigation of the supramolecular behaviour of copper(II) complexes with the 5-phenylimidazole/perchlorate ligand system (`blend') remarkable solvatomorphism has been observed. By employing a variety of crystallization solvents (polar protic, polar/non-polar aprotic), a series of 12 crystalline solvatomorphs with the general formula [Cu(ClO)(LH)]·x(solvent) have been obtained [LH = 5-phenylimidazole, x(solvent) = 3.3(HO) (1), 2(methanol) (2), 2(ethanol) (3), 2(1-propanol) (4), 2(2-propanol) (5), 2(2-butanol) (6), 2(dimethylformamide) (7), 2(acetone) (8), 2(tetrahydrofurane) (9), 2(1,4-dioxane) (10), 2(ethyl acetate) (11) and 1(diethyl ether) (12)].

Reactions of Cadmium(II) Halides and Di-2-Pyridyl Ketone Oxime: One-Dimensional Coordination Polymers.

The coordination chemistry of 2-pyridyl ketoximes continues to attract the interest of many inorganic chemistry groups around the world for a variety of reasons. Cadmium(II) complexes of such ligands have provided models of solvent extraction of this toxic metal ion from aqueous environments using 2-pyridyl ketoxime extractants. Di-2-pyridyl ketone oxime (dpkoxH) is a unique member of this family of ligands because its substituent on the oxime carbon bears another potential donor site, i.

Multifunctional role of zinc in human health: an update.

Zinc is a multipurpose trace element for the human body, as it plays a crucial part in various physiological processes, such as cell growth and development, metabolism, cognitive, reproductive, and immune system function. Its significance in human health is widely acknowledged, and this has led the scientific community towards more research that aims to uncover all of its beneficial properties, especially when compared to other essential metal ions. One notable area where zinc has shown beneficial effects is in the prevention and treatment of various diseases, including cancer.

Interesting chemical and physical features of the products of the reactions between trivalent lanthanoids and a tetradentate Schiff base derived from cyclohexane-1,2-diamine.

The initial use of a tetradentate Schiff base (LH) derived from the 2 : 1 condensation between 2-hydroxyacetophenone and cyclohexane-1,2-diamine in 4f-metal chemistry is described. The 1 : 2 reaction of Ln(NO)·HO (Ln = lanthanoid or yttrium) and LH in MeOH/CHCl has provided access to isostructural complexes [Ln(NO)(L'H)(MeOH)] in moderate to good yields. Surprisingly, the products contain the corresponding Schiff base ligand L'H possessing six aliphatic -CH- groups instead of the -CH-(CH)-CH- unit of the cyclohexane ring, an unusual ring-opening of the latter has occurred.

Heterometallic clusters based on an uncommon asymmetric "V-shaped" [Fe(μ-OR)Ln(μ-OR)Fe] (Ln = Gd, Tb, Dy, Ho) structural core and the investigation of the slow relaxation of the magnetization behaviour of the [FeDy] analogue.

The synthesis, crystal structures, Mössbauer spectra and variable temperature dc and ac magnetic susceptibility studies of a new family of trinuclear heterometallic Fe/Ln complexes, [FeLn(PhCO)((py)CO)((py)C(OMe)O)(NO)Cl] (Ln = Gd (1/Gd), Tb (1/Tb), Dy (1/Dy), and Ho (1/Ho)), where (py)CO and (py)C(OMe)O are the anions of the -diol and hemiketal derivatives of di-2-pyridyl ketone, are reported. Compounds 1/Ln are based on an asymmetric "V-shaped" [Fe(μ-OR)Ln(μ-OR)Fe] structural core formed from the connection of the two terminal Fe centers to the central Ln ion either through one or two alkoxide groups originating from the alkoxide-type bridging ligands. Direct current magnetic susceptibility studies reveal the presence of weak antiferromagnetic interactions between the Fe ions.

Biological Effects of Human Exposure to Environmental Cadmium.

Cadmium (Cd) is a toxic metal for the human organism and for all ecosystems. Cd is naturally found at low levels; however, higher amounts of Cd in the environment result from human activities as it spreads into the air and water in the form of micropollutants as a consequence of industrial processes, pollution, waste incineration, and electronic waste recycling. The human body has a limited ability to respond to Cd exposure since the metal does not undergo metabolic degradation into less toxic species and is only poorly excreted.

Structural modeling of protein ensembles between E3 RING ligases and SARS-CoV-2: The role of zinc binding domains.

Background: The ubiquitin system is a modification process with many different cellular functions including immune signaling and antiviral functions. E3 ubiquitin ligases are enzymes that recruit an E2 ubiquitin-conjugating enzyme bound to ubiquitin in order to catalyze the transfer of ubiquitin from the E2 to a protein substrate. The RING E3s, the most abundant type of ubiquitin ligases, are characterized by a zinc (II)-binding domain called RING (Really Interesting New Gene).

Indium(III)/2-benzoylpyridine chemistry: interesting indium(III) bromide-assisted transformations of the ligand.

Reactions of 2-benzoylpyridine, (py)(ph)CO, with InX (X = Cl, Br) in EtOH at room temperature have been studied. The InCl/(py)(ph)CO system has provided access to complex [InCl{(py)(ph)CO}(EtOH)]·{(py)(ph)CO} (1) and the byproduct {(pyH)(ph)CO}Cl (2). The reaction of InBr with (py)(ph)CO has led to a mixture of (L)[InBr{(py)(ph)CO}] (3) and [InBr{(py)(ph)CH(O)}(EtOH)] (4), where L is the 9-oxo-indolo[1,2-]pyridinium cation and (py)(ph)CH(O) is the anion of (pyridin-2-yl)methanol.

Novel Co and Ni Metal Complexes and Ferromagnets by the Combination of 2-Pyridyl Oximes with Polycarboxylic Ligands.

The use of 2-pyridyl oximes in metal complexes chemistry has been extensively investigated in the last few decades as a fruitful source of species with interesting magnetic properties. In this work, the initial combination of pyridine-2-amidoxime (pyaoxH) and 2-methyl pyridyl ketoxime (mpkoH) with isonicotinic acid (HINA) and 3,5-pyrazole dicarboxylic acid (Hpdc) has provided access to three new compounds, [Ni(INA)(pyaox)(pyaoxH)(DMF)] (), [Co(mpko)(mpkoH)(OMe)(HO)](ClO) (), and [Co(OH)(Hpdc)(Hpdc)] (). displays a square-planar metal topology, being the first example that bears simultaneously HINA and pyaoxH in their neutral or ionic form.

Two different coordination modes of the Schiff base derived from ortho-vanillin and 2-(2-aminomethyl)pyridine in a mononuclear uranyl complex.

This work describes the reaction of the potentially tetradentate Schiff-base ligand -(2-pyridylmethy)-3-methoxysalicylaldimine (HL) with UO(OCMe)·2HO and UO(NO)· 6HO in MeOH in the absence or presence of an external base, respectively. The product from these reactions is the mononuclear complex [UO(L)] (). Its structure has been determined by single-crystal, X-ray crystallography.

Confirming the Molecular Basis of the Solvent Extraction of Cadmium(II) Using 2-Pyridyl Oximes through a Synthetic Inorganic Chemistry Approach and a Proposal for More Efficient Extractants.

The present work describes the reactions of CdI with 2-pyridyl aldoxime (2paoH), 3-pyridyl aldoxime (3paoH), 4-pyridyl aldoxime (4paoH), 2-6-diacetylpyridine dioxime (dapdoH) and 2,6-pyridyl diamidoxime (LH). The primary goal was to contribute to understanding the molecular basis of the very good liquid extraction ability of 2-pyridyl ketoximes with long aliphatic chains towards toxic Cd(II) and the inability of their 4-pyridyl isomers for this extraction. Our systematic investigation provided access to coordination complexes [CdI(2paoH)] (), {[CdI(3paoH)]} (), {[CdI(4paoH)]} () and [CdI(dapdoH] ().

Wet-chemistry assembly of one-dimensional nanowires: switching characteristics of a known spin-crossover iron(II) complex through Raman spectroscopy.

In this study, a simple, fast, one-pot approach for the isolation of nanowires (NWs) in coordination chemistry is reported. Nanowires (NWs) of spin-crossover (SCO) materials are extremely rare. Here, an innovative and easy synthetic process was developed to prepare NWs of a switchable polymorph of the known complex -[Fe(NCS)(abpt)] using a wet-chemistry approach for the first time; abpt is the bidentate chelating ligand 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole.

High nuclearity structurally - related Mn supertetrahedral T4 aggregates.

The simultaneous employment of 1,3-propanediol and di-2-pyridyl ketone in Mn carboxylate chemistry has provided access to three new, structurally-related [Mn] and [Mn] clusters. They are based on nanosized supertetrahedal T4 Mn/O structural cores and exhibit slow relaxation of magnetization below 3.5 K.

Pentanuclear Thorium(IV) Coordination Cluster from the Use of Di(2-pyridyl) Ketone.

The Th(NO)·5HO/di(2-pyridyl) ketone [(py)CO] reaction system gives a pentanuclear cluster containing the doubly deprotonated form of the -diol derivative of the ligand. The cluster consists of a tetrahedral arrangement of four Th ions centered on the fifth ion, which is the first characterized Th complex. The analysis of its structure reveals that this is a Kuratowski-type coordination compound.

A SARS-CoV-2 -human metalloproteome interaction map.

The recent pandemic caused by the novel coronavirus resulted in the greatest global health crisis since the Spanish flu pandemic of 1918. There is limited knowledge of whether SARS-CoV-2 is physically associated with human metalloproteins. Recently, high-confidence, experimentally supported protein-protein interactions between SARS-CoV-2 and human proteins were reported.

Dinuclear Lanthanide(III) Complexes from the Use of Methyl 2-Pyridyl Ketoxime: Synthetic, Structural, and Physical Studies.

The first use of methyl 2-pyridyl ketoxime (mepaoH) in homometallic lanthanide(III) [Ln(III)] chemistry is described. The 1:2 reactions of Ln(NO)·HO (Ln = Nd, Eu, Gd, Tb, Dy; = 5, 6) and mepaoH in MeCN have provided access to complexes [Ln(OCMe)(NO)(mepaoH)] (Ln = Nd, ; Ln = Eu, ; Ln = Gd, ; Ln = Tb, ; Ln = Dy, ); the acetato ligands derive from the Ln-mediated hydrolysis of MeCN. The 1:1 and 1:2 reactions between Dy(OCMe)·4HO and mepaoH in MeOH/MeCN led to the all-acetato complex [Dy(OCMe)(mepaoH)] ().

Indium(III) in the "Periodic Table" of Di(2-pyridyl) Ketone: An Unprecedented Transformation of the Ligand and Solid-State In NMR Spectroscopy as a Valuable Structural Tool.

Reactions of di(2-pyridyl) ketone, (py)CO, with indium(III) halides in CHNO have been studied, and a new transformation of the ligand has been revealed. In the presence of In, the C═O bond of (py)CO is subjected to nucleophilic attack by the carbanion :CHNO, yielding the dinuclear complexes [InX{(py)C(CHNO)(O)}] (X = Cl, ; X = Br, ; X = I, ) in moderate to good yields. The alkoxo oxygens of the two η:η:η-(py)C(CHNO)(O) ligands doubly bridge the In centers and create a {In(μ-OR)} core.

Further synthetic investigation of the general lanthanoid(iii) [Ln(iii)]/copper(ii)/pyridine-2,6-dimethanol/carboxylate reaction system: {CuLn} coordination clusters (Ln = Dy, Tb, Ho) and their yttrium(iii) analogue.

In addition to previously studied {CuGd}, {CuGd}, {CuLn} and {CuLn} coordination clusters (Ln = trivalent lanthanide) containing pdm or Hpdm ligands (Hpdm = pyridine-2,6-dimethanol) and ancillary carboxylate groups (RCO), the present work reports the synthesis and study of three new members of a fifth family of such complexes. Compounds [CuLnO(OMe)(NO)(OCCHBu)(pdm)(MeOH)] (Ln = Dy, 1; Ln = Tb, 2; Ln = Ho, 3) were prepared from the reaction of Ln(NO)·xHO (x = 5, 6), CuX·yHO (X = ClO, Cl, NO; y = 6, 2 and 3, respectively), Hpdm, BuCHCOH and EtN (2 : 2.5 : 2 : 1 : 9) in MeCN/MeOH.

Asymmetric Dinuclear Lanthanide(III) Complexes from the Use of a Ligand Derived from 2-Acetylpyridine and Picolinoylhydrazide: Synthetic, Structural and Magnetic Studies.

A family of four Ln(III) complexes has been synthesized with the general formula [Ln(NO)(L)(S)] (Ln = Gd, Tb, Er, and S = HO; , and , respectively/Ln = Dy, S = MeOH, complex ), where HL is the flexible ditopic ligand '-(1-(pyridin-2-yl)ethylidene)pyridine-2-carbohydrazide. The structures of isostructural MeOH/HO solvates of these complexes were determined by single-crystal X-ray diffraction. The two Ln ions are doubly bridged by the deprotonated oxygen atoms of two "head-to-head" 2.

Oligonuclear Actinoid Complexes with Schiff Bases as Ligands-Older Achievements and Recent Progress.

Even 155 years after their first synthesis, Schiff bases continue to surprise inorganic chemists. Schiff-base ligands have played a major role in the development of modern coordination chemistry because of their relevance to a number of interdisciplinary research fields. The chemistry, properties and applications of transition metal and lanthanoid complexes with Schiff-base ligands are now quite mature.

Tetranuclear oxido-bridged thorium(iv) clusters obtained using tridentate Schiff bases.

Thorium(iv) complexes are currently attracting intense attention from inorganic chemists due to the development of liquid-fluoride thorium reactors and the fact that thorium(iv) is often used as a model system for the study of the more radioactive Np(iv) and Pu(iv). Schiff-base complexes of tetravalent actinides are useful for the development of new separation strategies in nuclear fuel processing and nuclear waste management. Thorium(iv)-Schiff base complexes find applications in the colorimetric detection of this toxic metal ion and the construction of fluorescent on/off sensors for Th(iv) exploiting the ligand-based light emission of its complexes.

Multifunctionality in Two Families of Dinuclear Lanthanide(III) Complexes with a Tridentate Schiff-Base Ligand.

The employment of -(2-carboxyphenyl)salicylideneimine in 4f metal chemistry has led to two families of dinuclear complexes depending on the lanthanide(III) used. Representative members exhibit interesting magnetic, optical, and catalytic properties.

Modeling the Solvent Extraction of Cadmium(II) from Aqueous Chloride Solutions by 2-pyridyl Ketoximes: A Coordination Chemistry Approach.

The goal of this work is to model the nature of the chemical species [CdCl(extractant)] that are formed during the solvent (or liquid-liquid) extraction of the toxic cadmium(II) from chloride-containing aqueous media using hydrophobic 2-pyridyl ketoximes as extractants. Our coordination chemistry approach involves the study of the reactions between cadmium(II) chloride dihydrate and phenyl 2-pyridyl ketoxime (phpaoH) in water-containing acetone. The reactions have provided access to complexes [CdCl(phpaoH)]∙HO (∙HO) and {[CdCl(phpaoH)]} (); the solid-state structures of which have been determined by single-crystal X-ray crystallography.