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A relatively unexplored approach in heterometallic chemistry of transition metals and lanthanides has been developed toward the controlled synthesis of a new family of linear heterotrinuclear Ln(III)-Pd(II)-Ln(III) complexes with the general formula [Ln 2 Pd(pao) 2 (NO 3 ) 6 (MeOH) 2 (H 2 O) 2 ]·[Pd(pao) 2 ] 4 , where Ln III = Dy III (2), Gd III (3), Er III (4) and Yb III (5). This strategy was based on the diamagnetic 'metalloligand' [Pd(pao) 2 ] (1), where pao - is the anion of 2-pyridinealdoxime, containing two dangling oximate O-atoms which were trans to each other and available for binding with oxophilic lanthanide ions. Because of their trans -configuration, the [Pd(pao) 2 ] 'metalloligand' was able to direct the binding of two {Ln(NO 3 ) 3 (MeOH)(H 2 O)} units on opposite sites, thus yielding the reported trinuclear {Ln-Pd-Ln} clusters. Complexes 2-5 constitute a new family of trinuclear heterometallic {Ln 2 Pd} species, and they represent the first examples of a directional assembly approach towards the coordination of 4f-metal ions. Compounds 2 and 5 exhibit out-of-phase signals under applied dc fields of 300 and 2000 Oe, respectively, characteristics of the slow magnetization relaxation, albeit with very small energy barriers for the magnetization reversal. This was due to the combined onset of fast quantum tunneling and the weak crystal field effects induced by the coordinated ligands. The combined results highlight the potential of using the 'metal complexes as ligands' method to deliberately prepare heterometallic Pd II -Ln III complexes with unique structural and interesting physicochemical (magnetic, optical, catalytic) properties.

The employment of the [1+1] condensation approach for the preparation of new macrocyclic scaffolds (LN6 and LN3O3) towards high-performance Dy(III) single-molecule magnets (SMMs) with pseudo-D 6h symmetry is described. Engineering of the macrocycles denticity from LN6 to LN3O3 leads to a mononuclear SMM with a large U eff value of 1300 K. The experimental results are supported by ab initio calculations, which indicate relaxation of the magnetization via the second-excited state.

The enantiomerically pure Schiff base ligands H 2 L-S and H 2 L-R yield chiral heterometallic dodecanuclear complexes of the form [Cu 8 Ln 4 (OH) 8 (OMe) 4 (O 2 CBu t ) 8 (L-S or L-R) 4 (H 2 O) 4 ] where Ln III =Gd (1S), Tb (2S), Dy (3S, 3R), Ho (4S, 4R), Er (5S) or Y (6S, 6R) and H 2 L=(S or R)-2-{[(1-hydroxypropan-2-yl)imino]methyl}-6-methoxyphenol. The complexes are isomorphous and crystallize in the non-centrosymmetric polar space group C2 in enantiomeric conformation. The chirality of the Schiff base ligands originates from the respective S- or R- enantiomer of 2-aminopropan-1-ol, is imparted to the complexes and to the crystals that belong to non-centrosymmetric space group. The chirality and enantiomeric conformation of all complexes are retained in dmso solutions as confirmed by Circular Dichroism spectra which consist of mirror images, expected for enantiomeric pairs. All complexes consist of four distorted cubane-like subunits [Cu 2 Ln 2 (μ 3 -OH) 2 (μ 3 -OMe)(μ 3 -OR)], which share the Ln III ions and result in a cyclic distorted tetragonal arrangement; each edge of the {Ln III 4 } quadrilateral is occupied by two μ-OH - ions that further bridge to a Cu II ion. Magnetic susceptibility measurements revealed ferromagnetic interactions for 3S with Ln III =Dy and antiferromagnetic interactions for all other complexes. AC susceptibility data of 3S under 1 kOe external dc field indicate slow magnetic relaxation phenomena below 2 K., (© 2024 The Authors. ChemPlusChem published by Wiley-VCH GmbH.)

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.e., a second 2-pyridyl group. The goal of this study was to investigate the reactions of cadmium(II) halides and dpkoxH in order to assess the structural role (if any) of the halogeno ligand and compare the products with their zinc(II) analogs. The synthetic studies provided access to complexes {[CdCl 2 (dpkoxH)∙2H 2 O]} n ( 1 ∙2H 2 O), {[CdBr 2 (dpkoxH)]} n ( 2 ) and {[CdI 2 (dpkoxH)]} n ( 3 ) in 50-60% yields. The structures of the complexes were determined by single-crystal X-ray crystallography. The compounds consist of structurally similar 1D zigzag chains, but only 2 and 3 are strictly isomorphous. Neighboring Cd II atoms are alternately doubly bridged by halogeno and dpkoxH ligands, the latter adopting the η 1 :η 1 :η 1 :μ (or 2.0111 using Harris notation) coordination mode. A terminal halogeno group completes distorted octahedral coordination at each metal ion, and the coordination sphere of the Cd II atoms is {Cd II (η 1 - X)(μ - X) 2 (N pyridyl ) 2 (N oxime )} (X = Cl, Br, I). The trans -donor-atom pairs in 1 ∙2H 2 O are Cl terminal /N oxime and two Cl bridging /N pyridyl ; on the contrary, these donor-atom pairs are X terminal /N pyridyl , X bridging /N oxime, and X bridging /N pyridyl (X = Br, I). There are intrachain H-bonding interactions in the structures. The packing of the chains in 1 ∙2H 2 O is achieved via π-π stacking interactions, while the 3D architecture of the isomorphous 2 and 3 is built via C-H∙∙∙C g (C g is the centroid of one pyridyl ring) and π-π overlaps. The molecular structures of 1 ∙2H 2 O and 2 are different compared with their [ZnX 2 (dpkoxH)] (X = Cl, Br) analogs. The polymeric compounds were characterized by IR and Raman spectroscopies in the solid state, and the data were interpreted in terms of the known molecular structures. The solid-state structures of the complexes are not retained in DMSO, as proven via NMR ( 1 H, 13 C, and 113 Cd NMR) spectroscopy and molar conductivity data. The complexes completely release the coordinated dpkoxH molecule, and the dominant species in solution seem to be [Cd(DMSO) 6 ] 2+ in the case of the chloro and bromo complexes and [CdI 2 (DMSO) 4 ].

Two copper(I) polymorphs of formula [Cu(SALH)(TPP) 3 ] (1a and 1b) were prepared by the conjugation of the Non-Steroidal Anti-Inflammatory Drug (NSAID) salicylic acid (SALH 2 ) with the mitochondriotropic agent triphenylphosphine (TPP) via metal ion. For comparison, the isomorph [Ag(SALH)(TPP) 3 ] (2) was prepared. The conjugates 1a, 1b and 2 were characterized by melting point (m.p.), Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy, Ultraviolet-Visible (UV-Vis) spectroscopy and nuclear magnetic resonance ( 1 H NMR). The crystal structures of 1a, 1b and 2 were confirmed by X-ray diffraction crystallography (XRD). The ex vivo binding affinity of 1-2 towards CT (calf thymus)-DNA was studied by UV, fluorescence, viscosity and DNA Thermal Denaturation studies. Their inhibitory activity against lipoxygenase (LOX) (an enzyme which is mainly located in the mitochondrion) was determined. The in vitro activity of 1-2 was evaluated against human breast cancer cell lines MCF-7 (hormone depended (HD)) and MDA-MB 281 (hormone independent (HI)) cells. Compounds 1-2 inhibit stronger than cisplatin the cancerous cells. The molecular mechanism of action of 1-2 was suspected by the MCF-7 cells morphology and confirmed by DNA fragmentation, Acridine Orange/Ethidium Bromide (AO/EB) Staining and mitochondrial membrane permeabilization tests., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The intramolecular Diels-Alder reaction (IMDA) of a butenolide derivative, as an entry to the type II abyssomicin scaffold, and the total synthesis of (±)-abyssomicin 2 and (±)-neoabyssomicin B are reported for the first time. A facile route to the IMDA precursor, the formation of a type I intermediate and two paths to (±)-neoabyssomicin B are also discussed.

Reactions of methyl-2-pyridyl ketone, pyCOMe, with FeCl 3 ·6H 2 O in various solvents gave complexes [Fe 4 Cl 6 (OMe) 2 (L1) 2 ]·0.7MeCN·0.4MeOH (1·0.7MeCN·0.4MeOH) and [Fe 3 Cl 4 (bicine)(L2)]·Me 2 CO·0.2H 2 O (2·Me 2 CO·0.2H 2 O). The ligands (L1) 2- = pyCO(Me)CHCOpy (in 1) and (L2) 2- = pyCO(Me)CH 2 CO(OMe)py (in 2) are formed in situ , through an aldol reaction-type mechanism between the carbanion pyC(O)CH 2 - (formed by the nucleophilic attack of the MeO - in pyCOMe) and pyCOMe which results in the formation of a new C-C bond. The intermediate compound undergoes attack in the -CH 2 - or -CO- group by a MeO - group, and the new ligands (L1) 2- and (L2) 2- , respectively, are formed. The molecular structure of 1 consists of three corner-sharing [Fe 2 O 2 ] rhombic units in cis -arrangement. The two terminal Fe III ions display distorted square pyramidal geometry and the two central Fe III ions are distorted octahedral. The molecular structure of 2 consists of two corner-sharing [Fe 2 O 2 ] rhombic units, with the two terminal Fe III ions in distorted square pyramidal geometry and the central Fe III in distorted octahedral. The differentiation in the coordination environment of the Fe III ions in 1-2 is reflected in the values of the Mössbauer hyperfine parameters. In agreement with theoretical calculations, the square pyramidal sites exhibit a smaller isomer shift value in comparison to the octahedral sites. Magnetic studies indicate antiferromagnetic interactions leading to an S = 0 ground state in 1 and to an S = 5/2 ground state in 2, consistent with Electron Paramagnetic Resonance spectroscopy. Mössbauer spectra of 2 indicate the onset of relaxation effects below 80 K. At 1.5 K the spectrum of 2 consists of magnetic sextets. The determined hyperfine magnetic fields are consistent with the exchange coupling scheme imposed by the crystal structure of 2. Theoretical calculations shed light on the differences in the electronic structure between the square pyramidal and the octahedral sites.

The systematic investigation of the general reaction scheme Dy III /X - /LH 2 , where X - = Cl - , CF 3 SO 3 - , ClO 4 - , MeCO 2 - , and LH 2 is the pocket-type ligand 2,6-diacetylpyridine bis(picolinoylhydrazone), resulting from the condensation of 2,6-diacetylpyridine with picolinic acid hydrazide, has led to a new family of mono-, di-, and tetranuclear metal complexes of the formulae [DyCl 2 (LH 2 )(MeOH)]Cl (1), [Dy 2 (O 3 SCF 3 ) 2 (LH) 2 (MeOH) 1.42 (H 2 O) 0.58 ](O 3 SCF 3 ) 2 (2), [Dy 2 (LH) 2 (MeOH) 2 (H 2 O) 2 ](ClO 4 ) 4 (3), and [Dy 4 (OH) 2 (O 2 CMe) 6 (L) 2 ] (4), respectively. The organic chelate undergoes metal-assisted amide-iminol tautomerism and adopts the neutral zwitterionic, and single- and double-deprotonated forms, respectively, upon coordination with the metal center(s). Interestingly, the different forms of the ligand LH 2 /LH - /L 2- act independently as penta-, hexa-, and heptadentate, either as single-chelating or chelating and bridging, thus yielding new Dy III compounds of various nuclearities and different magnetic properties. All complexes 1-4 exhibit frequency-dependent, out-of-phase ( χ '' M ) tails of signals in zero external dc field, characteristic of the onset of quantum tunnelling of magnetization. Attempts to suppress the tunnelling through the application of an external dc field were mostly successful in the case of complex 1, where entirely visible peaks of χ '' M have been observed and rendered possible the fit of the data to the Arrhenius equation, thus yielding the parameters: U eff = 10.9(1) K and τ 0 = 1.9(1) × 10 -6 s, where U eff is the effective energy barrier for the magnetization reversal and τ 0 is the pre-exponential factor. The combined results demonstrate the ability of pyridyl-bis(acylhydrazone) ligands to yield chemically, structurally, and magnetically interesting compounds through their rich interconversion between various amide-iminol resonance forms.

This work describes the reaction of the potentially tetradentate Schiff-base ligand N -(2-pyridylmethy)-3-methoxysalicylaldimine (HL) with UO 2 (O 2 CMe) 2 ·2H 2 O and UO 2 (NO 3 ) 2 · 6H 2 O in MeOH in the absence or presence of an external base, respectively. The product from these reactions is the mononuclear complex [UO 2 (L) 2 ] ( 1 ). Its structure has been determined by single-crystal, X-ray crystallography. The anionic ligand adopts two different coordination modes (1.1011, 1.1010; Harris notation) in the complex. The new compound was fully characterized by solid-state (IR, Raman and Photoluminescence spectroscopies) and solution (UV-Vis and 1 H NMR spectra, conductivity measurements) techniques., Competing Interests: The authors declare no conflict of interest., (© 2022 The Author(s).)

The organoantimony derivative of formula trans-O,O-[Ph 3 Sb V (Carv) 2 ] (TPAC) (CarvH = carvacrol) is obtained by the oxidation of triphenylstibine (Ph 3 Sb III ) with hydrogen peroxide in the presence of carvacrol (CarvH). Physical methods such as X-ray Fluorescence (XRF) spectroscopy, single crystal and powder X-ray diffraction analysis (XRD and PXRD), Attenuated Total Reflection Fourier Transform Infra-red (ATR-FTIR) spectroscopy, Thermogravimetric Differential Thermal Analysis (TG-DTA) and Differential Scanning Calorimetry (DTG/DSC), confirm the retention of the formula of TPAC throughout the sample mass in solid state, while UV-Vis spectroscopy in the solution. TPAC is the first example of carvacrol (the main ingredient of oregano) covalently bonded to any metal ion. Only the trans-O,O-[Ph 3 Sb(Carv) 2 ] isomer was isolated suggesting stereo-selectivity of the preparation route. TPAC inhibits in vitro both human breast adenocarcinoma cell lines: MCF-7 (positive to hormones receptor (HR +)), MDA-MB-231 (negative to hormones receptor (HR-)) stronger than normal human fetal lung fibroblast cells (MRC-5). The MCF-7 cells morphology, DNA fragmentation, Acridine Orange/Ethidium Bromide (AO/EB) Staining, cell cycle arrest and mitochondrial membrane permeabilization tests suggest an apoptotic pathway for cell death, especially, through the mitochondrion damage. The binding type of TPAC toward the calf thymus CT-DNA was initially deduced ex vivo from the differentiation of the DNA solution viscosity. Fluorescence spectroscopy confirms the interaction mode suggested. Spectroscopic evidence (FTIR, UV-Vis) suggest that glutathione (GSH) (a tripeptide over-expressed in tumor cells) induces conversion of non-active pentavalent antimony, which is contained in TPAC, to active trivalent one, providing a new strategy for the development of targeted chemotherapeutics., (© 2022. The Author(s), under exclusive licence to Society for Biological Inorganic Chemistry (SBIC).)

We report here on the synthesis, crystal structure, optoelectronic and vibrational properties, as well as the DFT calculations of the novel trimethylsulfonium tin trichloride (CH 3 ) 3 SSnCl 3 . The air-stable compound is prepared by reacting the (CH 3 ) 3 SCl and SnCl 2 solid precursors in evacuated silica tubes at 100 °C. According to powder X-ray diffraction and Rietveld refinement, it crystallizes at room temperature in the orthorhombic space group Pbca (No. 61) with isolated pyramids of [SnCl 3 ] - and (CH 3 ) 3 S + units. UV-vis reflectance and photoluminescence spectroscopies reveal a direct energy band gap of 3.85 eV, accompanied by a broad Stokes-shifted luminescence signal. Photoexcitation of the compound at room temperature and at -196 °C results in broadband luminescence with weak magenta emission centered at 400 nm using an excitation at 250 nm. First principal calculations provide insight into the physical properties through the electron and phonon density of states. Multitemperature Raman spectroscopy and differential scanning calorimetry reveal a reversible phase transition at ca. 70 °C that affects the vibrational modes of the [SnCl 3 ] - . By dissolving (CH 3 ) 3 SSnCl 3 in dimethylformamide in ambient air for a week, oxidation of tin occurs in the "defect" perovskite ((CH 3 ) 3 S) 2 SnCl 6 . The crystal structure of ((CH 3 ) 3 S) 2 SnCl 6 is also determined with high accuracy via single-crystal X-ray diffraction (cubic space group Pa -3 (No. 205)) and compared with (CH 3 ) 3 SSnCl 3 via Hirshfeld surface analysis.

Novel nickel(ii) complexes bearing ( t butyl)bis(diphenylphosphanyl)amine and different halogenido ligands, [Ni(P,P)X 2 ] = [Ni{ t BuN(PPh 2 ) 2 -κ 2 P}X 2 ], (X = Cl, Br, I) are prepared, characterized by IR and NMR spectroscopy, mass spectrometry and X-ray crystallography, and tested as catalysts in the Kumada cross-coupling reaction of model substituted iodobenzenes and p -tolylmagnesium bromide. The data obtained together with DFT calculations indicate that these new catalysts operate in the Ni(i)-Ni(iii) mode. The highest catalytic activity and selectivity are exhibited by [Ni(P,P)Cl 2 ], which is most easily reduced by the used Grignard reagent to the Ni(i) state. This process is much more energy demanding in the case of the bromido and iodido complexes, causing the appearance of the induction period. [Ni(P,P)Cl 2 ] is also very active in the cross-couplings of substrates with iodine atoms sterically shielded by ortho substituents. The data obtained are in good accordance with the described positive effect of the increased electron-releasing power of N -substituents R' on the overall catalytic performance of [Ni{R'N(PPh 2 ) 2 -κ 2 P}X 2 ] complexes., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The fac -[M(CO) 3 (PyA)(P)] and cis-trans -[M(CO) 2 (PyA)(P) 2 ] neutral complexes (M is Re or 99m Tc), based on the mixed ligand strategy with pyrazine-2-carboxylic acid (PyAH) as the bidentate N,O and triphenylphosphine as the monodentate P ligand, are presented. Through the employment of the anhydride of pyrazine-2,3-dicarboxylic acid (PyDA), the PyAH scaffold was conveniently derivatized with the model bioactive amine 1-(2-methoxyphenyl)piperazine, the active part of the 5-HT 1A antagonist WAY100635. Reaction of either PyAH or the pharmacophore-bearing PyAH ligand (L 1 H) with fac- [M(CO) 3 ] + core in water yielded the intermediate fac -[M(CO) 3 (PyA)(H 2 O)] complexes. The labile aqua ligand was easily replaced by PPh 3 to yield the fac -[Re(CO) 3 (PyA)(PPh 3 )] complexes, while in toluene under reflux, the cis-trans -[Re(CO) 2 (PyA)(PPh 3 ) 2 ] complexes were obtained. The latter complexes were alternatively obtained from mer -[Re(CO) 3 (PPh 3 ) 2 Cl] by refluxing with the PyA ligand in toluene. The analogous 99m Tc complexes were synthesized quantitatively, showing excellent stability in competition studies. The methodology described herein represents a practical procedure for the effective integration of the fac -[M(CO) 3 ] + core with amine-bearing biologically active compounds for diagnosis/therapy.

The poor handling and hygiene practices of contact lenses are the key reasons for their frequent contamination, and are responsible for developing ocular complications, such as microbial keratitis (MK). Thus there is a strong demand for the development of biomaterials of which contact lenses are made, combined with antimicrobial agents. For this purpose, the known water soluble silver(I) covalent polymers of glycine (GlyH), urea (U) and the salicylic acid (SalH 2 ) of formulae [Ag 3 (Gly) 2 NO 3 ] n (AGGLY), [Ag(U)NO 3 ] n (AGU), and dimeric [Ag(salH)] 2 (AGSAL) were used. Water solutions of AGGLY, AGU and AGSAL were dispersed in polymeric hydrogels using hydroxyethyl-methacrylate (HEMA) to form the biomaterials pHEMA@AGGLY-2, pHEMA@AGU-2, and pHEMA@AGSAL-2. The biomaterials were characterized by X-ray fluorescence (XRF) spectroscopy, thermogravimetric differential thermal analysis (TG-DTA), differential scanning calorimetry (DTG/DSC), attenuated total reflection spectroscopy (FT-IR-ATR) and single crystal diffraction analysis. The antibacterial activity of AGGLY, AGU, AGSAL, pHEMA@AGGLY-2, pHEMA@AGU-2 and pHEMA@AGSAL-2 was evaluated against the Gram negative species Pseudomonas aeruginosa ( P. aeruginosa ) and Gram positive ones Staphylococcus epidermidis ( S. epidermidis ) and Staphylococcus aureus ( S. aureus ), which mainly colonize in contact lenses. The in vitro toxicity of the biomaterials and their ingredients was evaluated against normal human corneal epithelial cells (HCECs) whereas the in vitro genotoxicity was evaluated by the micronucleus (MN) assay in HCECs. The Artemia salina and Allium cepa models were applied for the evaluation of in vivo toxicity and genotoxicity of the materials. Following our studies, the new biomaterials pHEMA@AGGLY-2, pHEMA@AGU-2, and pHEMA@AGSAL-2 are suggested as efficient candidates for the development of antimicrobial contact lenses.

The Th(NO 3 ) 4 ·5H 2 O/di(2-pyridyl) ketone [(py) 2 CO] reaction system gives a pentanuclear cluster containing the doubly deprotonated form of the gem -diol derivative of the ligand. The cluster consists of a tetrahedral arrangement of four Th IV ions centered on the fifth ion, which is the first characterized Th IV 5 complex. The analysis of its structure reveals that this is a Kuratowski-type coordination compound.

Diabetes mellitus is a debilitating disease, plaguing a significant number of people around the globe. Attempts to develop new drugs on well-defined atoxic metalloforms, which are capable of influencing fundamental cellular processes overcoming insulin resistance, has triggered an upsurge in molecular research linked to zinc metallodrugs. To that end, meticulous efforts were launched toward the design and synthesis of materials with insulin mimetic potential. Henceforth, trigonelline and N-(2-hydroxyethyl)-iminodiacetic acid (HEIDAH 2 ) were selected as organic substrates seeking binding to zinc (Zn(II)), with new crystalline compounds characterized by elemental analysis, FT-IR, X-rays, thermogravimetry (TGA), luminescence, NMR, and ESI-MS spectrometry. Physicochemical characterization was followed by in vitro biochemical experiments, in which three out of the five zinc compounds emerged as atoxic, exhibiting bio-activity profiles reflecting enhanced adipogenic potential. Concurrently, well-defined qualitative-quantitative experiments provided links to genetic loci responsible for the observed effects, thereby unraveling their key involvement in signaling pathways in adipocyte tissue and insulin mimetic behavior. The collective results (a) signify the quintessential role of molecular studies in unearthing unknown facets of pathophysiological events in diabetes mellitus II, (b) reflect the close associations of properly configured molecular zincoforms to well-defined biological profiles, and (c) set the stage for further physicochemical-based development of efficient zinc antidiabetic metallodrugs.

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 3 ) 3 · n H 2 O (Ln = Nd, Eu, Gd, Tb, Dy; n = 5, 6) and mepaoH in MeCN have provided access to complexes [Ln 2 (O 2 CMe) 4 (NO 3 ) 2 (mepaoH) 2 ] (Ln = Nd, 1 ; Ln = Eu, 2 ; Ln = Gd, 3 ; Ln = Tb, 4 ; Ln = Dy, 5 ); the acetato ligands derive from the Ln III -mediated hydrolysis of MeCN. The 1:1 and 1:2 reactions between Dy(O 2 CMe) 3 ·4H 2 O and mepaoH in MeOH/MeCN led to the all-acetato complex [Dy 2 (O 2 CMe) 6 (mepaoH) 2 ] ( 6 ). Treatment of 6 with one equivalent of HNO 3 gave 5 . The structures of 1 , 5, and 6 were solved by single-crystal X-ray crystallography. Elemental analyses and IR spectroscopy provide strong evidence that 2 - 4 display similar structural characteristics with 1 and 5 . The structures of 1 - 5 consist of dinuclear molecules in which the two Ln III centers are bridged by two bidentate bridging ( η 1 : η 1 : μ 2 ) and two chelating-bridging ( η 1 : η 2 : μ 2 ) acetate groups. The Ln III atoms are each chelated by a N , N '-bidentate mepaoH ligand and a near-symmetrical bidentate nitrato group. The molecular structure of 6 is similar to that of 5 , the main difference being the presence of two chelating acetato groups in the former instead of the two chelating nitrato groups in the latter. The geometry of the 9-coordinate Ln III centers in 1 , 5 and 6 can be best described as a muffin-type (MFF-9). The 3D lattices of the isomorphous 1 and 5 are built through H-bonding, π⋯π stacking and C-H⋯π interactions, while the 3D architecture of 6 is stabilized by H bonds. The IR spectra of the complexes are discussed in terms of the coordination modes of the organic and inorganic ligands involved. The Eu(III) complex 2 displays a red, metal-ion centered emission in the solid state; the Tb III atom in solid 4 emits light in the same region with the ligand. Magnetic susceptibility studies in the 2.0-300 K range reveal weak antiferromagnetic intramolecular Gd III… Gd III exchange interactions in 3 ; the J value is -0.09(1) cm -1 based on the spin Hamiltonian Ĥ = -J(Ŝ Gd1 ·Ŝ Gd2 ).

The new water soluble silver(I) complex of glycine (GlyH) with formula [Ag 3 (Gly) 2 NO 3 ] n (AGGLY) was synthesized. The compound was characterized by melting point (m.p.), Fourier-transform infrared (FT-IR), Ultraviolet-visible (UV-vis) and Nuclear Magnetic Resonance ( 1 H-, 13 C NMR) spectroscopic techniques and X-ray crystallography. The in vitro cytotoxic activity of AGGLY against human breast adenocarcinoma cell lines: MCF-7 (hormone depended (HD)) and MDA-MB-231 (hormone independent (HI)) was determined. For comparison other adenocarcinoma cells such as human cervical adenocarcinoma (HeLa) cells and lung adenocarcinoma cells (A549) were also screened. AGGLY inhibits both breast cancer cell lines stronger than cisplatin. On the contrary, AGGLY, exhibits lower toxicity against fetal lung fibroblast (MRC-5) cells than cisplatin. Its genotoxicity against MRC-5 cells was detected from the presence or absence of micronucleus using fluorescence microscopy, while the in vivo genotoxicity was evaluated using Allium cepa model. The MCF-7 cells morphology suggests apoptotic pathway for their death. The apoptotic pathway was confirmed by cell cycle arrest, Acridine Orange/Ethidium Bromide (AO/EB) Staining, and permeabilization of the mitochondrial membrane tests. The molecular mechanism of action was further studied by the binding affinity of AGGLY towards the calf thymus (CT) DNA., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Metal-organic frameworks represent a porous class of materials that are build up from metal ions or oligonuclear metallic complexes and organic ligands. They can be considered as sub-class of coordination polymers and can be extended into one-dimension, two-dimensions, and three-dimensions. Depending on the size of the pores, MOFs are divided into nanoporous, mesoporous, and macroporous items. The latter two are usually amorphous. MOFs display high porosity, a large specific surface area, and high thermal stability due to the presence of coordination bonds. The pores can incorporate neutral molecules, such as solvent molecules, anions, and cations, depending on the overall charge of the MOF, gas molecules, and biomolecules. The structural diversity of the framework and the multifunctionality of the pores render this class of materials as candidates for a plethora of environmental and biomedical applications and also as catalysts, sensors, piezo/ferroelectric, thermoelectric, and magnetic materials. In the present review, the synthetic methods reported in the literature for preparing MOFs and their derived materials, and their potential applications in environment, energy, and biomedicine are discussed.

In addition to previously studied {CuGd 6 }, {CuGd 4 }, {CuLn 7 } and {CuLn 8 } coordination clusters (Ln = trivalent lanthanide) containing pdm 2- or Hpdm - ligands (H 2 pdm = pyridine-2,6-dimethanol) and ancillary carboxylate groups (RCO 2 - ), the present work reports the synthesis and study of three new members of a fifth family of such complexes. Compounds [Cu 5 Ln 4 O 2 (OMe) 4 (NO 3 ) 4 (O 2 CCH 2 Bu t ) 2 (pdm) 4 (MeOH) 2 ] (Ln = Dy, 1; Ln = Tb, 2; Ln = Ho, 3) were prepared from the reaction of Ln(NO 3 ) 3 ·xH 2 O (x = 5, 6), CuX 2 ·yH 2 O (X = ClO 4 , Cl, NO 3 ; y = 6, 2 and 3, respectively), H 2 pdm, Bu t CH 2 CO 2 H and Et 3 N (2 : 2.5 : 2 : 1 : 9) in MeCN/MeOH. Rather surprisingly, the copper(ii)/yttrium(iii) analogue has a slightly different composition, i.e. [Cu 5 Y 4 O 2 (OMe) 4 (NO 3 ) 2 (O 2 CCH 2 Bu t ) 4 (pdm) 4 (MeOH) 2 ] (4). The structures of 1·4MeCN·1.5MeOH and 4·2MeOH were solved by single-crystal X-ray crystallography. The five Cu II and four Dy III centres in 1 are held together by two μ 5 -O 2- , four μ-MeO - , two syn,synη 1 :η 1 :μ Bu t CH 2 CO 2 - , four η 2 :η 1 :η 2 :μ 3 pdm 2- (each of these groups chelates a Cu II atom and simultaneously bridges two Dy III atoms through its two -CH 2 O - arms) and two μ-MeOH ligands. The four terminal nitrato groups each chelate (η 1 :η 1 ) a Dy III centre. The five Cu II atoms are co-planar (by symmetry) forming a bow-tie arrangement; the four outer Cu II atoms form a rectangle with edges of 3.061(1) and 6.076(1) Å. The four Dy III centres also form a rectangle that lies above and below the plane of the Cu II centres, with edges of 3.739(1) and 5.328(1) Å. The two strictly planar rectangles are almost perpendicular. Two trigonal bipyramidal μ 5 -O 2- groups link the perpendicular Cu 5 and Dy 4 frameworks together. The molecule 4 has a very similar structure to that of 1, differences being the replacement of the two chelating nitrato groups of 1 by two chelating Bu t CH 2 CO 2 - ligands in 4 and the coordination polyhedra of the Ln III and Y III atoms (Snub diphenoids in 1 and biaugmented trigonal prisms in 4). Dc magnetic susceptibility data (χ M ) on analytically pure samples of 1-3, collected in the 300-2 K range, indicate that ferromagnetic exchange interactions dominate leading to large spin ground states. The χ M T vs. T data for 4 suggest moderately strong antiferromagnetic Cu II Cu II exchange interactions. Studies of the dynamic magnetic properties of the {Cu 5 Ln 4 } clusters show that 1 behaves as a SMM at zero field and 2 is a very weak field-induced SMM, while 3 exhibits only weak tails in the χ'' M vs. T plots at various ac frequencies at zero dc field.

Two novel copper (II) complexes, namely [Cu(2,2'-pq)(NO 3 )](NO 3 ) (1) and [Cu(2,2'-pq) 2 (NO 3 )](NO 3 )·6H 2 O(2) where 2,2'-pq is 2-(2'-pyridyl quinoxaline) were synthesized and characterized by various spectral methods. Complex 2 characterized by single crystal X-ray diffraction showed a distorted trigonal bipyramidal geometry and crystallized together with an hexamer, (H 2 O) 6 cluster, with R 6 6 (12) topology and chair conformation. The interaction of Calf Thymus DNA (CT-DNA) with 1 and 2 was investigated by UV-Visible absorption spectra, Viscosity, Cyclic Voltammetry, Fluorescence and Circular Dichroism (CD), indicating that both complexes can bind to DNA both by means of intercalation and groove binding. Their DNA interaction mode depends on their concentrations and the differences between their structures. Cleavage experiments were performed by agarose gel electrophoresis using pBR322 DNA both in dark and after illumination. Furthermore, the cytotoxicity of both complexes was evaluated against MCF-7 and healthy cells (HEK-293) by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays; moreover their cell uptake against MCF-7 tumor cells and HEK-293 normal cells was revealed by using confocal laser scanning. Both complexes have the potential to act as effective anticancer drugs with 2 to present an IC 50 smaller than that of cis-platin and also to be useful for optically probing tumor cells since it fluoresces at blue and green when is treated with MCF-7 cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The reaction of the Schiff base ligand o -OH-C 6 H 4 -CH=N-C(CH 2 OH) 3 , H 4 L, with Ni(O 2 CMe) 2 ∙4H 2 O and lanthanide nitrate salts in a 4 : 2 : 1 ratio lead to the formation of the trinuclear complexes [Ni 2 Ln(H 3 L) 4 (O 2 CMe) 2 ](NO 3 ) (Ln = Sm ( 1 ), Eu ( 2 ), Gd ( 3 ), Tb ( 4 )). The complex cations contain the strictly linear Ni II -Ln III -Ni II moiety. The central Ln III ion is bridged to each of the terminal Ni II ions through two deprotonated phenolato groups from two different ligands. Each terminal Ni II ion is bound to two ligands in distorted octahedral N 2 O 4 environment. The central lanthanide ion is coordinated to four phenolato oxygen atoms from the four ligands, and four carboxylato oxygen atoms from two acetates which are bound in the bidentate chelate mode. The lattice structure of complex 4 consists of two interpenetrating, supramolecular diamond like lattices formed through hydrogen bonds among neighboring trinuclear clusters. The magnetic properties of 1 - 4 were studied. For 3 the best fit of the magnetic susceptibility and isothermal M ( H ) data gave J NiGd = +0.42 cm -1 , D = +2.95 cm -1 with g Ni = g Gd = 1.98. The ferromagnetic nature of the intramolecular Ni···Gd interaction revealed ground state of total spin S = 11/2. The magnetocaloric effect (MCE) parameters for 3 show that the change of the magnetic entropy (-Δ S m ) reaches a maximum of 14.2 J kg -1 K -1 at 2 K. A brief literature survey of complexes containing the Ni II -Ln III -Ni II moiety is discussed in terms of their structural properties.

Strain effects on g and metal hyperfine coupling tensors, A , are often manifested in Electron Paramagnetic Resonance (EPR) spectra of transition metal complexes, as a result of their intrinsic and/or solvent-mediated structural variations. Although distributions of these tensors are quite common and well understood in continuous-wave (cw) EPR spectroscopy, reported strain effects on ligand hyperfine coupling constants are rather scarce. Here we explore the case of a conformationally flexible Cu(II) complex, [Cu{Ph 2 P(O)NP(O)Ph 2 -κ 2 O,O '} 2 ], bearing P atoms in its second coordination sphere and exhibiting two structurally distinct CuO 4 coordination spheres, namely a square planar and a tetrahedrally distorted one, as revealed by X-ray crystallography. The Hyperfine Sublevel Correlation (HYSCORE) spectra of this complex exhibit 31 P correlation ridges that have unusual inverse or so-called "boomerang" shapes and features that cannot be reproduced by standard simulation procedures assuming only one set of magnetic parameters. Our work shows that a distribution of isotropic hyperfine coupling constants (hfc) spanning a range between negative and positive values is necessary in order to describe in detail the unusual shapes of HYSCORE spectra. By employing DFT calculations we show that these hfc correspond to molecules showing variable distortions from square planar to tetrahedral geometry, and we demonstrate that line shape analysis of such HYSCORE spectra provides new insight into the conformation-dependent spectroscopic response of the spin system under investigation.

The [Zn 3 (CitH) 2 ] ( 1 ) (CitH 4 = citric acid), was dispersed in sodium lauryl sulphate (SLS) to form the micelle of SLS@[Zn 3 (CitH) 2 ] ( 2 ). This material 2 was incorporated in hydrogel made by hydroxyethyl-methacrylate (HEMA), an ingredient of contact lenses, toward the formation of pHEMA@(SLS@[Zn 3 (CitH) 2 ]) ( 3 ). Samples of 1 and 2 were characterized by UV-Vis, 1 H-NMR, FT-IR, FT-Raman, single crystal X-ray crystallography, X-ray fluorescence analysis, atomic absorption and TG/DTA/DSC. The antibacterial activity of 1 - 3 as well as of SLS against Gram-positive (Staphylococcus epidermidis (St. epidermidis) and Staphylococcus aureus (St. aureus)) and Gram-negative (Pseudomonas aeruginosa (PAO1) , and Escherichia coli (E. coli)) bacteria was evaluated by the means of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and inhibitory zone (IZ). 2 showed 10 to 20-fold higher activity than 1 against the bacteria tested. Moreover the 3 decreases the abundance of Gram-positive microbes up to 30% ( St. aureus ) and up to 20% (PAO1) the Gram-negative ones. The noteworthy antimicrobial activity of the obtained composite 3 suggests an effective antimicrobial additive for infection-free contact lenses.

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. Clusters of Th(iv) with hydroxide, oxide or peroxide bridges are also relevant to the environmental and geological chemistry of this metal ion. The reactions between Th(NO 3 ) 4 ·5H 2 O and N-salicylidene-o-aminophenol (LH 2 ) and N-salicylidene-o-amino-4-methylphenol (L'H 2 ) in MeCN have provided access to complexes [Th 4 O(NO 3 ) 2 (LH) 2 (L) 5 ] (1) and [Th 4 O(NO 3 ) 2 (L'H) 2 (L') 5 ] (2) in moderate yields. The structures of 1·4MeCN and 2·2.4 MeCN have been determined by single-crystal X-ray crystallography. The complexes have similar molecular structures possessing the {Th 4 (μ 4 -O)(μ-OR') 8 } core that contains the extremely rare {Th 4 (μ 4 -O)} unit. The four Th IV atoms are arranged at the vertexes of a distorted tetrahedron with a central μ 4 -O 2- ion bonded to each metal ion. The H atom of one of the acidic -OH groups of each 3.21 LH - or L'H - ligand is located on the imine nitrogen atom, thus blocking its coordination. The Th IV centres are also held together by one 3.221 L 2- or (L') 2- group and four 2.211 L 2- or (L') 2- ligands. The metal ions adopt three different coordination numbers (8, 9, and 10) with a total of four coordination geometries (triangular dodecahedral, muffin, biaugmented trigonal prismatic, and sphenocorona). A variety of H-bonding interactions create 1D chains and 2D layers in the crystal structures of 1·4 MeCN and 2·2.4 MeCN, respectively. The structures of the complexes are compared with those of the uranyl complexes with the same or similar ligands. Solid-state and IR data are discussed in terms of the coordination mode of the organic ligands and the nitrato groups. 1 H NMR data suggest that solid-state structures are not retained in DMSO. The solid complexes emit green light at room temperature upon excitation at 400 nm, the emission being ligand-centered.

The employment of N -(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.

The quest for effective treatments of oxidative stress has concentrated over the years on new nanomaterials with improved antioxidant and antiradical activity, thereby attracting broad research interest. In that regard, research efforts in our lab were launched to pursue such hybrid materials involving a) synthesis of silica gel matrices, b) evaluation of the suitability of atoxic matrices as potential carriers for the controlled release of V(IV)(VOSO 4 ), V(V)(NaVO 3 ) compounds and a newly synthesized heterometallic lithium-vanadium(IV,V) tetranuclear compound containing vanadium-bound hydroxycarboxylic 1,3-diamine-2-propanol-N,N,N',N'-tetraacetic acid (DPOT), and c) investigation of structural and textural properties of silica nanoparticles (NPs) by different and complementary characterization techniques, inquiring into the nature of the encapsulated vanadium species and their interaction with the siloxane matrix, collectively targeting novel antioxidant and antiradical nanomaterials biotechnology. The physicochemical characterization of the vanadium-loaded SiO 2 NPs led to the formulation of optimized material configuration linked to the delivery of the encapsulated antioxidant-antiradical load. Entrapment and drug release studies showed a) the competence of hybrid nanoparticles with respect to encapsulation efficiency of the vanadium compound (concentration dependence), b) congruence with the physicochemical features determined, and c) a well-defined release profile of NP load. Antioxidant properties and the free radical scavenging capacity of the new hybrid materials (containing VOSO 4 , NaVO 3 , and V-DPOT) were demonstrated through a) 2-diphenyl-1-picrylhydrazyl (DPPH) free radical, and b) intracellular-extracellular reactive oxygen species (ROS) assays, through UV-Visible spectroscopy techniques, collectively showing that the hybrid silica NPs (empty-loaded) could serve as an efficient platform for nanodrug formulations counteracting oxidative stress., (Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.)

Redox-active compounds such as copper-phenanthroline are known as artificial/chemical nucleases with a great impact and potential for their applications as metallotherapeutics. In that vein, the mononuclear copper(II) complexes [Cu(L) 2 (bipy)] (1), [Cu(L) 2 (bipy)(H 2 O)] (2) and [Cu(L) 2 (phen)(H 2 O)] (3), where L = 2-thiophene carboxylate, bipy = 2,2΄-bipyridine and phen = 1,10-phenanthroline, have been prepared and pharmacochemically studied, while the crystal structure of 1 is also reported. All the tested complexes preferably bind to CT-DNA via minor groove as resulted from UV spectroscopy studies, luminescent titration, EB competition assays and viscosity measurements. Complexes 2 and 3 in aqua behave like a "light switch" for DNA. The intensity enhancement, with the increase of DNA concentration, reached about 3-fold for 2 and 10-fold for 3. In vitro antioxidant activity of compounds 1-3, was evaluated using two different antioxidant assays: a) interaction with 1,1-diphenyl-2-picryl-hydrazyl (DPPH) stable free radical and b) inhibition of lipid peroxidation. Moreover, their inhibitory activity on soybean lipoxygenase (LOX) was evaluated for their anti-inflammatory potency. The tested complexes showed good activity on both lipid peroxidation and soybean LOX inhibition while complex 2 exhibited the best antioxidant/anti-inflammatory activity. A computational analysis over the LOX protein structure 1JNQ was performed, in an effort to support their possible mode of action. The cytotoxicity of the complexes was determined and their efficacy against several human cancer cell lines (ovarian, OAW-42; lung, A549; colon, HT29; breast, MDA-MB-231; kidney, Caki-2; and cervical, Hela) and human non-tumor cell lines (lung, MRC-5; and breast, MTSV1-7) were evaluated. The best cytotoxic activity was appeared for complex 3. In silico, computational methods support antiestrogen activity of the administered complexes on normal breast cells., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The antibacterial effect of the already known water-soluble compound {[Ag 6 (μ 3 -Hmna) 4 (μ 3 -mna) 2 ] 2- ·[(Et 3 NH) + ] 2 ·(DMSO) 2 ·(H 2 O)} (AGMNA) (H 2 mna = 2‑mercapto‑nicotinic acid) was evaluated by the mean of the Minimum Inhibitory Concentration (MIC), the Minimum Bactericidal Concentration (MBC) and the Inhibitory Zone (IZ), against the bacterial strains Pseudomonas aeruginosa (PAO1) and Staphylococcus aureus (St. aureus) which settle in the cornea, in bacterial keratitis. The MICs' of AGMNA against PAO1 and St. aureus were 25.7 ± 2.4 μM and 42.0 ± 0.3 μM respectively. Τhe Biofilm Elimination Concentration (ΒΕC) was used to evaluate the influence of AGMNA on the formation of biofilm of PAO1. AGMNA exhibits stronger antimicrobial activity than that of H 2 mna or AgNO 3 . The toxicity of AGMNA was examined against normal human corneal epithelial cells (HCET cells) and by micronucleus (MN) assay in HCET cells. Thus, the IC 50 value of AGMNA, towards HCET cells is higher than 120 μΜ, while its effect on MN frequency, of HCET cells, is meaningless, when they are treated with it at 120 μΜ, suggesting no in vitro genotoxicity. The Mitotic Index (MI), Chromosomal Aberrations (CA) and Nuclear Abnormalities (NA) analyses of Allium cepa reveal insignificant variations between treated and untreated ones indicating no in vivo genotoxicity., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The initial use of anils, i.e. bidentate Schiff bases derived from the condensation of anilines with salicylaldehyde or its derivatives, in 4f-metal chemistry is described. The 1 : 1 reactions between Ln(NO3)3·xH2O (Ln = lanthanide) or Y(NO3)3·6H2O and N-(5-bromosalicylidene)aniline (5BrsalanH) in MeCN has provided access to complexes [Ln(NO3)3(5BrsalanH)2(H2O)]·MeCN (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) and [Y(NO3)3(5BrsalanH)2(H2O)]·MeCN, respectively, in good yields. The structures of the isomorphous complexes with Ln = Pr(1·MeCN), Sm(3·MeCN), Gd(5·MeCN), Dy(7·MeCN) and Er(9·MeCN) have been determined by single-crystal X-ray crystallography. The other complexes were proven to be isostructural with the fully structurally characterized compounds based on elemental analyses, IR spectra, unit cell determinations and powder X-ray patterns. The 9-coordinate LnIII centre in the [Ln(NO3)3(5BrsalanH)2(H2O)] molecules is bound to six oxygen atoms from the three bidentate chelating nitrato groups, two oxygen atoms that belong to the organic ligands and one oxygen atom from the aquo ligand. The 5BrsalanH molecules behave as monodentate O-donors; the acidic H atom is clearly located on the imino N atom and thus the formally neutral ligands adopt an extremely rare coordination mode participating in the zwitterionic form. The coordination polyhedra defined by the nine donor atoms around the LnIII centres are best described as spherical capped square antiprisms. Various intermolecular interactions build the crystal structures and Hirshfeld surface analysis was applied to evaluate the magnitude of interactions between the molecules. Solid-state IR and UV/VIS data are discussed in terms of structural features. 1H NMR data prove that the diamagnetic [Y(NO3)3(5BrsalanH)2(H2O)] complex decomposes in DMSO. Combined dc and ac magnetic susceptibility, as well as magnetization data for 7 suggest that this complex shows field-induced slow magnetic relaxation. Two magnetization relaxation processes are evident. The fit to the Arrhenius law has been performed using the 6.5-8.5 K ac data, affording an effective barrier for the magnetization reversal of 27 cm-1. Cole-Cole plot analysis in the temperature range in which the Orbach relaxation process is assumed, reveals a narrow distribution of relaxation times. The solid Dy(iii) complex 7 emits green light at 338 nm, the emission being ligand-centered. The perspectives of the present, first results in the lanthanide(iii)-anil chemistry are critically discussed.

The new silver(I) ionic, water soluble, compound {[Ag(CIPH) 2 ]NO 3 ∙0.75MeOH∙1.2H 2 O} (CIPAG) was obtained by reacting silver(I) nitrate with the antibiotic ciprofloxacin (CIPH). The complex was characterized by m.p., mid-FT-IR, 1 H-NMR, UV-Vis spectroscopic techniques. The crystal structures of both CIPAG and the hexahydrated neutral free drug {[CIPH]∙6(H 2 O)} (2) were characterized by X-ray crystallography. Two neutral ligands are datively bonded to the metal ion through the piperidinic nitrogen atoms forming a cationic {[Ag(CIPH) 2 ] + } counter part which is neutralized by a nitrate group. The antibacterial effect of CIPAG and the commercially available hydrochloric salt of the antibiotic ({[CIPH 2 + ]∙Cl - } (3)) were tested against the bacterial species Pseudomonas aeruginosa (PAO1), Staphylococcus epidermidis (St. epidermidis) and Staphylococcus aureus (St. aureus) by the mean of minimum inhibitory concentration, minimum bactericidal concentration and their inhibitory zone (IZ). The influence of CIPAG and 3 against the formation of biofilm of PAO1 or St. aureus was also evaluated by mean of biofilm elimination concentration. The IZ caused by CIPAG which has been loaded in poly-hydroxyethylmethacrylate, is determined. The genotoxicity of CIPAG and 3 is tested in vitro against normal human corneal epithelial cells (HCET cells), by the presence of micronucleus in HCET cells and in vivo by mean of Allium cepa test.

In an attempt to understand the aqueous interactions of Cr(III) with low-molecular mass physiological ligands and examine its role as an adipogenic metallodrug agent in Diabetes mellitus II, the pH-specific synthesis in the binary-ternary Cr(III)-(HA = hydroxycarboxylic acid)-(N,N)-aromatic chelator (AC) (HA = 2-hydroxyethyl iminodiacetic acid/heidaH 2 , quinic acid; AC = 1,10-phenanthroline/phen) systems was pursued, leading to four new crystalline compounds. All materials were characterized by elemental analysis, UV-Visible, FT-IR, and ESI-MS spectroscopy, cyclic voltammetry, and X-Ray crystallography. Concurrently, the aqueous speciation of the binary Cr(III)-(2-hydroxyethyl iminodiacetic acid) system, complemented by ESI-MS, provided key-details of the species in solution correlating with the solid-state species. The structurally distinct Cr(III) soluble species were subsequently used in an in vitro investigation of their cytotoxic activity in 3T3-L1 fibroblast cultures. Compound 1 exhibited solubility, bioavailability, and atoxicity over a wide concentration range (0.1-100 μΜ) in contrast to 3, which was toxic. The adipogenic potential of 1 was subsequently investigated toward transformation of pre-adipocytes into mature adipocytes. Confirmation of that capacity relied on molecular biological techniques a) involving genes (glucose transporter type 4, peroxisome proliferator-activated receptor gamma, glucokinase, and adiponectin) serving as sensors of the transformation process, b) comparing the Cr(III)-adipogenicity potential to that of insulin, and c) exemplifying the ultimate maturity of adipocytes poised to catabolize glucose. The collective effort points out salient structural features in the coordination sphere of Cr(III) inducing adipogenic transformation relevant to combating hyperglycemia. The multiply targeted mechanistic insight into such a process exemplifies the role of well-defined Cr(III) complex forms as potential insulin-mimetic adipogenic agents in Diabetes mellitus II., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The use of 2-pyridinealdoxime (paoH), methyl 2-pyridyl ketone oxime (mepaoH), phenyl 2-pyridyl ketone oxime (phpaoH) and pyridine-2-amidoxime (NH 2 paoH) for the synthesis of dinuclear Co III /Dy III complexes is described in the absence or presence of an external base. Complexes [CoDy(pao) 3 (NO 3 ) 3 ] (1), [CoDy(mepao) 3 (NO 3 ) 3 ] (2), [CoDy(phpao) 3 (NO 3 ) 3 ] (3) and [CoDy(NH 2 pao) 3 (NO 3 ) 3 ]·3MeOH (4·3MeOH) have been isolated and their structures have been determined by single-crystal X-ray crystallography. The complexes crystallize in non-centrosymmetric (2, 3) or centrosymmetric (1, 4·3MeOH) trigonal space groups and form a family of triply-oximate bridged dinuclear Co(iii)-Dy(iii) complexes. The crystals of 1, 3 and 4·3MeOH contain mixtures of Δ and Λ enantiomers, whereas complex 2 is enantiomerically pure (Λ). A 3-fold crystallographic axis (C 3 ) passes through two metal ions in all complexes. The low-spin Co III and Dy III ions are bridged by three oximate groups belonging to the η 1 :η 1 :η 1 :μ 2-pyridyloximate ligands. The Co III centre is octahedrally coordinated by the six nitrogen atoms of the deprotonated organic ligands in a facial arrangement. The Dy III centre is bound to an O 9 set of donor atoms, its coordination sphere being completed by three bidentate chelating nitrato groups. The coordination polyhedron around Dy III in 1 is best described as the Johnson tricapped trigonal prism, while the coordination geometries of the Dy III centres in 2, 3 and 4·3MeOH are best described as consisting of spherical tricapped trigonal prismatic coordination polyhedra. The spectroscopic data of the complexes are also reported and discussed in the infra-red region in terms of the coordination modes of the ligands involved. The magnetic properties of these complexes were studied between 300 and 1.8 K revealing mainly the depopulation of the Dy III m j sublevels of the ground 6 H 15/2 state. The intrinsic magnetic anisotropy of the Dy III centers is clearly observed by the non-superimposed magnetization (M) versus H/T data, but single-molecule magnet (SMM) properties were detected only for the mepao - -containing complex 2. The origin of these properties in 2 is critically discussed and supported by computational studies.

The reaction of ZnCl 2 with the non-steroidal anti-inflammatory drug niflumic acid (Hnif) resulted in the formation of complex [Zn(nif-O) 2 (MeOH) 4 ], 1. When this reaction was performed in the presence of a N,N'-donor heterocyclic ligand such as 2,2'-bipyridine (bipy), 2,2'-bipyridylamine (bipyam), 1,10-phenanthroline (phen) and 2,2'-dipyridylketone oxime (Hpko), the complexes [Zn(nif-O,O')(bipy)Cl], 2, [Zn(nif-O)(nif-O,O') 2 (bipyam)], 3, [Zn(nif-O,O') 2 (phen)], 4 and [Zn(nif-O) 2 (Hpko-N,N') 2 ], 5 were formed, respectively. The complexes were characterized by physicochemical and spectroscopic techniques and X-ray crystallography (for complexes 1-3). The complexes can scavenge 1,1-diphenyl-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals, may inhibit soybean lipoxygenase and are more active compounds than free Hnif. The interaction of the complexes with serum albumins was monitored by fluorescence emission spectroscopy and the corresponding binding constants were calculated. The affinity of the complexes with calf-thymus DNA was investigated by UV-vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide revealing their interaction probably via intercalation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The reaction of mixtures of Fe(O 2 CMe) 2 ·2H 2 O and Ni(O 2 CMe) 2 ·4H 2 O of various compositions with di-2-pyridyl ketone (py 2 CO, dpk) in MeCN under an inert atmosphere afforded a family of hetero-metallic enneanuclear clusters with general formula [Fe 9-x Ni x (μ 4 -OH) 2 (O 2 CMe) 8 (py 2 CO 2 ) 4 ] (2, x = 1.00; 3: x = 6.02; 4, x = 7.46; 5, x = 7.81). Clusters 2-5 are isomorphous to the homo-metallic [Fe 9 ] cluster (1) previously reported by some of us, and also isostructural to the known homo-metallic [Ni 9 ] cluster. All four clusters contain a central M II ion in an unusual 8-coordinate site and eight peripheral M II ions in distorted octahedral environments. The distribution of Fe II and Ni II ions over these two distinct coordination sites in 2-5 can be established through a combination of X-ray fluorescence and Mössbauer spectroscopies, which show that Fe II preferentially occupies the unique 8-coordinate metal site while Ni II accumulates in the octahedral holes. Density functional theory indicates that the distribution of ions across the two sites arises not from any intrinsic preference of the Fe II ions for the 8-coordinate sites, but rather because of the large ligand field stabilization energy available to Ni II in octahedral coordination.

One-pot reactions between the [Mn 3 O(O 2 CPh) 6 (py) x ] +/0 triangular precursors and either CaBr 2 ·xH 2 O or CaCl 2 ·6H 2 O, in the presence of salicylhydroxamic acid (shaH 2 ), have afforded the heterometallic complexes [Mn III 4 Ca 2 (O 2 CPh) 4 (shi) 4 (H 2 O) 3 (Me 2 CO)] (1) and (pyH)[Mn II 2 Mn III 4 Ca 2 Cl 2 (O 2 CPh) 7 (shi) 4 (py) 4 ] (2), respectively, in good yields. Further reactions but using a more flexible synthetic scheme comprising the Mn(NO 3 ) 2 ·4H 2 O/Ca(NO 3 ) 2 ·4H 2 O and Mn(O 2 CPh) 2 ·2H 2 O/Ca(ClO 4 ) 2 ·4H 2 O "metal blends" and shaH 2 , in the presence of external base NEt 3 , led to the new complexes (NHEt 3 ) 2 [Mn III 4 Mn IV 4 Ca(OEt) 2 (shi) 10 (EtOH) 2 ] (3) and (NHEt 3 ) 4 [Mn III 8 Ca 2 (CO 3 ) 4 (shi) 8 ] (4), respectively. In all reported compounds, the anion of the tetradentate (N,O,O,O)-chelating/bridging ligand salicylhydroxime (shi 3- ), resulting from the in situ metal-ion-assisted amide-iminol tautomerism of shaH 2 , was found to bridge both Mn and Ca atoms. Complexes 1-4 exhibit a variety of different structures, metal stoichiometries, and Mn oxidation-state descriptions; 1 possesses an overall octahedral metal arrangement, 2 can be described as a Mn 4 Ca 2 octahedron bound to an additional Mn 2 unit, 3 consists of a Mn 8 "ring" surrounding a Ca II atom, and 4 adopts a rectangular cuboidal motif of eight Mn atoms accommodating two Ca II atoms. Solid-state direct-current magnetic susceptibility studies revealed the presence of predominant antiferromagnetic exchange interactions between the Mn centers, leading to S = 0 spin ground-state values for all complexes. From a bioinorganic chemistry perspective, the reported compounds may demonstrate some relevance to both high-valent scheme (3) and lower-oxidation-level species (1, 2, and 4) of the catalytic cycle of the oxygen-evolving complex.

Nucleophilic attack by the carbanion - :CH 2 COCH 3 at the carbonyl group of di-2-pyridyl ketone, (py) 2 CO, in the presence of Cu II under moderately basic conditions has yielded the cationic mononuclear complex [Cu{(py) 2 C(CH 2 COCH 3 )(OH)} 2 ](NO 3 ) 2 ·2H 2 O (1·2H 2 O) in ∼40% yield, where (py) 2 C(CH 2 COCH 3 )(OH) is the ligand bis(2-pyridine-2-yl)butane-1-ol-3-one. The Cu II atom of the cation sits on a crystallographically imposed inversion center. The neutral molecule is coordinated to the metal ion as a tridentate fac chelating ligand through the hydroxyl oxygen atom and two 2-pyridyl nitrogen atoms. The pyridyl nitrogens are strongly coordinated to the metal ion, while the hydroxyl oxygen atoms form weak bonds with Cu II . The coordination geometry at the Cu II center is elongated octahedral. Various interactions build the crystal structure of the complex and Hirshfeld surface analysis was applied to evaluate the magnitude of interactions between the different chemical species in the crystal of 1·2H 2 O. IR, Raman and UV/VIS data of the solid complex are discussed in terms of the coordination mode of (py) 2 C(CH 2 COCH 3 )(OH), the ionic nature of nitrates and the stereochemistry at copper(ii). The complex was studied in a frozen solution (MeOH-toluene, 1 : 1 v/v) by CW-EPR spectroscopy and advanced EPR methods such as ENDOR and HYSCORE. The results show that the low symmetry of the cation is retained in solution, with the four nitrogen atoms arranged in a square planar configuration and the unpaired electron residing in an orbital pointing towards them. The bonding parameters in the first coordination sphere and the spin density distribution have been fully analyzed based on the ligand hyperfine coupling constants.

Seeking for copper based metallo-therapeutics, three triple bridged dinuclear copper(II) complexes [Cu 2 (μ 2 -L 2 )(bipy) 2 (μ 2 -OH)(μ 2 -H 2 O)](NO 3 ) 2 ·H 2 O (1·H 2 O), [Cu 2 (μ 2 -L 2 )(bipy) 2 (μ 2 -OH)(μ 2 -NO 3 )](NO 3 )·0.6MeOH·0.4H 2 O (2·0.6MeOH·0.4H 2 O) and [Cu 2 (μ 2 -L 1 )(bipy) 2 (μ 2 -OH)(μ 2 -NO 3 )(H 2 O)](NO 3 )·2H 2 O (3·2H 2 O) where L 2 =2-thiophene acetato, L 1 =2-thiophene carboxylato and bipy=2,2'-bipyridine were synthesized and structurally characterized. The complexes were subjected in vitro to a pharmacochemical evaluation for their antioxidant/anti-inflammatory activity, cytotoxicity and efficacy against human ovarian, lung, colon, breast, kidney and cervical cancer cell lines along with non tumor human lung and breast cell lines. The biological results support the structure related cytotoxic activity of the compounds. Complex 3 presented a combination of best anticancer and anti-inflammatory activities. A computational analysis over the LOX-3 protein structure 1JNQ was performed to support the possible mode of action., (Copyright © 2017 Elsevier B.V. All rights reserved.)

From the reaction of ZnCl 2 with the non-steroidal anti-inflammatory drug diflunisal (Hdifl), complex [Zn(difl-O) 2 (MeOH) 4 ], 1 was formed, while in the presence of a N,N'-donor heterocyclic ligand 2,2'-bipyridylamine (bipyam), 2,2'-bipyridine (bipy), 1,10-phenanthroline (phen) and 2,2'-dipyridylketone oxime (Hpko), the complexes [Zn(difl-O,O') 2 (bipyam)], 2, [Zn(difl-O,O') 2 (bipy)], 3, [Zn(difl-O,O') 2 (phen)], 4 and [Zn(difl-O) 2 (Hpko) 2 ], 5 were isolated, respectively. The complexes were characterized by physicochemical and spectroscopic techniques and the crystal structures of complexes 2, 3 and 5 were determined by X-ray crystallography. The ability of the complexes to scavenge 1,1-diphenyl-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals and to inhibit soybean lipoxygenase was studied and the complexes were more active than free Hdifl. The interaction of the complexes with serum albumins was monitored by fluorescence emission spectroscopy and the corresponding binding constants were calculated. UV-vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide were employed to investigate the interaction of the complexes with calf-thymus DNA and revealed intercalation as the most possible DNA-binding mode. Computational techniques were used to identify possible binding sites of albumins and DNA, and determine the druggability of human and bovine serum albumins with the five novel complexes. The majority of the complexes are stronger binders than the free Hdifl. This is the first study incorporating experimental and computational results to explore the binding activity of metal-NSAID complexes with DNA and serum albumins, suggesting their application as potential metallodrugs., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Breast cancer (BrCa) remains an unmet medical need despite the revolutionary development of antibody treatments and protein kinase inhibitors. In the current study, a series of novel substituted pyridopyrazine derivatives have been rationally designed and evaluated as multi-kinase inhibitors in the PI3K pathway. The target compounds were prepared from 6-amino-2-picoline, which upon nitration and selective reduction was converted to suitably substituted 6-methyl-7-aminopyrido[2,3-b]pyrazines. Suitable manipulation of the former amines provided the designed analogues, which were then assessed in vitro against several BrCa cell lines using the MTT cytotoxicity assay. The most potent compounds underwent evaluation in a broad spectrum of protein kinases, while their pharmacokinetic parameters were measured by LC-MS/MS. In vivo evaluation of a hit compound (14a) was performed in a HER2 amplified BrCa xenograft model (HCC1954) and efficacy was determined using Western blot based phosphokinase assays and immunohistochemistry. This derivative showed low micromolar cytotoxic potency in all BrCa cell lines, a mild inhibition of the PI3Kα wild type and H1047R mutated enzyme and excellent pharmacokinetic parameters following oral and intraperitoneal administration at the designed dose of 10 mg/kg, with absence of in vivo phenotypic toxicity. Interestingly, compound 14a inhibited the growth of xenografted tumors. Analysis of excised tumors from the treated animals showed a significantly reduced population of Ki-67 positive cells, as well as downregulated levels of phosphorylated AKT, ERK1/2 and SRC compared to vehicle treated animals. Finally, the specificity of 14a was assessed in a panel of 31 kinases where a mild, but direct, inhibition of the MET receptor tyrosine kinase was observed., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

The reactions of copper(ii) carboxylate sources with acetylacetone dioxime (acacdoH 2 ) in Me 2 CO have been studied and a novel, metal ion-assisted ligand transformation has been discovered. The reaction of [Cu 2 (diba) 4 (dibaH) 2 ] and acacdoH 2 (1 : 1.5) in Me 2 CO has provided access to the complex {[Cu 2 (diba) 4 (qunx)]} n (1) in low yield (25-30%), where dibaH is 3,3-dimethylbutyric acid and qunx is quinoxaline. The [Cu 2 (piv) 4 (pivH) 2 ]/acacdoH 2 (1 : 1.5) reaction system in warm Me 2 CO, where pivH is pivalic acid, gave the analogous complex {[Cu 2 (piv) 4 (qunx)]} n (2) in moderate yield (∼50%). Complexes 1 and 2 can be easily prepared by the direct 1 : 1 reactions between the corresponding copper(ii) carboxylate starting materials and qunx in Me 2 CO and MeOH, respectively. The formation of coordinated qunx in 1 and 2 is Cu II -promoted (assisted) as suggested by the failure to synthesize the free qunx by a variety of reactions of acacdoH 2 and Me 2 CO under aerobic conditions in the absence or even the presence of dibaH and pivH, respectively. The observed acacdoH 2 → qunx transformation is catalytic and new in the chemistry of the dioximes of β-diketones, and a mechanism has been proposed based on well-established reactions of organic chemistry. The mechanism is based on a double Beckmann rearrangement-type transformation and the overall scheme is represented by the 1 : 1 : 1 reaction between acacdoH 2 , Me 2 CO and O 2 . Complexes 1 and 2 have similar molecular structures consisting of paddle-wheel {Cu 2 (η 1 :η 1 :μ-O 2 CR) 4 } units bridged by qunx ligands in a zigzag 1D chain arrangement. The geometry of the Cu II ions is square pyramidal with a quinoxaline nitrogen atom occupying the apical position at each metal ion. Weak H bonds are present within the chains, the donors being qunx carbon atoms and the acceptors being coordinated carboxylate oxygen atoms. Neighbouring chains interact through C-Hπ interactions between diba - /piv - methyl groups and the "pyrazine" part of qunx forming layers which are stacked along the b (1) or a (2) axis through weak van der Waals interactions. The packing of the layers is different in the two structures, due to the different nature of the carboxylate ligands. Hirshfeld surface analysis of the two structures reveals the similarity of the interchain (intralayer) interactions. The IR and Raman data of 1 and 2 are discussed in terms of the coordination mode of the carboxylate groups and permit assignments of some characteristic bands/peaks of coordinated qunx. Dc magnetic susceptibility studies in the 1.8-310 K range reveal very strong antiferromagnetic Cu II Cu II exchange interactions within the carboxylate-bridged Cu 2 units (J = -479 K for 1 and -532 K for 2 using the H = - J∑S 1 ·S 2 spin Hamiltonian) and weaker antiferromagnetic interactions between the Cu 2 units via the qunx superexchange pathways, with the latter being ∼10% in strength compared to the former. A critical discussion of the acacdoH 2 → qunx transformation in 1 and 2 is provided in the light of other impressive, recently discovered Cu II -assisted transformations of acacdoH 2 , pointing out the key role of the solvent in the processes known to date.

The reaction of ZnCl 2 with the non-steroidal anti-inflammatory drug flufenamic acid (Hfluf) led to the formation of complex [Zn(fluf-O) 2 (MeOH) 4 ], 1. When the reaction takes places in the presence of a N,N'-donor heterocyclic ligand such as 2.2'-bipyridylamine (bipyam), 2.2'-bipyridine (bipy), 1.10-phenanthroline (phen) and 2.2'-dipyridylketone oxime (Hpko), the complexes [Zn(fluf) 2 (bipyam)], 2, [Zn(fluf) 2 (bipy)], 3, [Zn(fluf)(phen) 2 (H 2 O)](fluf)·0.2MeOH, 4·0.2MeOH and [Zn(fluf) 2 (Hpko) 2 ], 5 were isolated, respectively. The complexes were characterized by physicochemical and spectroscopic techniques and the crystal structures of complexes 2 and 4 were determined by X-ray crystallography. The ability of the complexes to scavenge 1.1-diphenyl-picrylhydrazyl, 2.2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals and to inhibit soybean lipoxygenase was evaluated; the complexes were more active than free Hfluf. The interaction of the complexes with serum albumins was investigated by fluorescence emission spectroscopy and the corresponding binding constants were calculated. UV-vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide were the techniques employed to monitor the interaction of the complexes with calf-thymus DNA and revealed intercalation as the most possible mode of binding., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Currently, the leading approach for extraction of uranium from seawater is selective sorption of UO2(2+) ions onto a poly(acrylamidoxime) fiber. Amidoxime functional groups are the most studied extractant moieties for this application, but are not perfectly selective, and understanding how these groups (and more generally the oxime groups) interact with UO2(2+) and competing ions in seawater is an important step in designing better extractants. We have started a new research programme aiming at in-depth studies of the uranyl-oxime/amidoxime interactions and we report here our first results which cover aspects of the coordination chemistry of 2-pyridyl ketoximes towards UO2(2+). Detailed synthetic investigations of various UO2(2+)/mepaoH and UO2(2+)/phpaoH reaction systems (mepaoH is methyl 2-pyridyl ketoxime and phpaoH is phenyl 2-pyridyl ketoxime) have provided access to the complexes [UO2(mepao)2(MeOH)2]{[UO2(NO3)(mepao)(MeOH)2]}2 (), [UO2(mepao)2(MeOH)2] (), [(UO2)2(O2)(O2CMe)2(mepaoH)2] () and [UO2(phpao)2(MeOH)2] (). The peroxido group in , which was isolated without the addition of external peroxide sources, probably arises from a bis(aquo)- and/or bis(hydroxido)-bridged diuranyl precursor in solution followed by photochemical oxidation of the bridging groups. The U(VI) atom in the [UO2(NO3)(mepao)(MeOH)2] molecules of () is surrounded by one nitrogen and seven oxygen atoms in a very distorted hexagonal bipyramidal geometry; two oxygen atoms from the terminal MeOH ligands, two oxygen atoms from the bidentate chelating nitrato group, and the oxygen and nitrogen atoms from the η(2) oximate group of the 1.110 (Harris notation) mepao(-) ligand define the equatorial plane. This plane consists of two terminal MeOH ligands and two η(2) oximate groups in the [UO2(mepao)2(MeOH)2] molecule () of . The structure of the [UO2(mepao)2(MeOH)2] molecule that is present in is very similar to the structure of the corresponding molecule in . The structure of the dinuclear molecule that is present in consists of two {UO2(O2CMe)(mepaoH)}(+) units bridged by a η(2):η(2):μ O2(2-) group. The equatorial plane of each uranyl site is composed of the pyridyl and oxime nitrogen atoms of a 1.011 mepaoH ligand, the oxygen atoms of an almost symmetrically coordinated bidentate chelating MeCO2(-) group and the two oxygen atoms of the peroxido groups. The core molecular structure of is similar to that of , the only difference being the presence of 1.110 phpao(-) ligands in the former instead of mepao(-) groups in the latter. The free pyridyl nitrogen atoms of mepao(-) and phpao(-) ligands of , and are acceptors of intramolecular H bonds from the ligated MeOH oxygen atoms. H-bonding and π-π stacking interactions build interesting supramolecular networks in the crystal structures of the four complexes. Compounds are the first structurally characterized uranyl complexes with 2-pyridyl aldoximes or ketoximes as ligands. IR data are discussed in terms of the coordination modes of the ligands in the complexes. (1)H NMR data in DMSO-d6 suggest that the complexes decompose in solution. The ESI(-) MS spectrum of dissolved in the NH4(O2CMe) buffer is indicative of the presence of [UO2(O2CMe)3](-), [UO2(O2CMe)2(phpao)](-), [UO2(O2CMe)(phpao)2](-) and [UO2(phpao)3](-) species. A common structural motif of the complexes containing the anionic mepao(-) (, ) and phpao(-) () ligands is that the deprotonated oximate group prefers to bind in the η(2) fashion forming a 3-membered chelating ring in spite of the presence of a pyridyl nitrogen atom, whose coordination would be expected to lead to 5- or 6-membered chelating rings.

In the title compound, [Re(C10H6NO2)(CO)3{As(C6H5)3}], the coordination environment of Re(I) is that of a distorted octa-hedron. Three coordination sites are occupied by three carbonyl groups in a facial arrangement and the remaining three sites by tri-phenyl-arsane and deprotonated quinaldic acid in As-mono- and N,O-bidentate fashions, respectively. In the crystal, the complexes are linked through weak C-H⋯O hydrogen bonds, forming a three-dimensional network. It worth noting that, as far as we know, this complex is the first Re(I) tri-phenyl-arsane tricarbonyl compound to be reported.

In the emerging issue of enhanced multi-resistant properties in infectious pathogens, new nanomaterials with optimally efficient antibacterial activity and lower toxicity than other species attract considerable research interest. In an effort to develop such efficient antibacterials, we a) synthesized acid-catalyzed silica-gel matrices, b) evaluated the suitability of these matrices as potential carrier materials for controlled release of ZnSO4 and a new Zn(II) binary complex with a suitably designed well-defined Schiff base, and c) investigated structural and textural properties of the nanomaterials. Physicochemical characterization of the (empty-loaded) silica-nanoparticles led to an optimized material configuration linked to the delivery of the encapsulated antibacterial zinc load. Entrapment and drug release studies showed the competence of hybrid nanoparticles with respect to the a) zinc loading capacity, b) congruence with zinc physicochemical attributes, and c) release profile of their zinc load. The material antimicrobial properties were demonstrated against Gram-positive (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus) and negative (Escherichia coli, Pseudomonas aeruginosa, Xanthomonas campestris) bacteria using modified agar diffusion methods. ZnSO4 showed less extensive antimicrobial behavior compared to Zn(II)-Schiff, implying that the Zn(II)-bound ligand enhances zinc antimicrobial properties. All zinc-loaded nanoparticles were less antimicrobially active than zinc compounds alone, as encapsulation controls their release, thereby attenuating their antimicrobial activity. To this end, as the amount of loaded zinc increases, the antimicrobial behavior of the nano-agent improves. Collectively, for the first time, sol-gel zinc-loaded silica-nanoparticles were shown to exhibit well-defined antimicrobial activity, justifying due attention to further development of antibacterial nanotechnology., (Copyright © 2015 Elsevier Inc. All rights reserved.)