Ethanol Ligands Research Articles

S-Allyl-4-(4-hydroxy-2-oxidobenzylidene-κO)-1-(2-oxidobenzylidene-κO)isothiosemicarbazidato-κ2N1,N4](ethanol-κO)dioxidouranium(VI) ethanol monosolvate

In the title compound, [U(C18H15N3O3S)O2(C2H5OH)]·C2H5OH, the UVI ion is in a distorted penta­gonal–bipyramidal coordination geometry, with two oxide O atoms in axial sites. Two N and two O atoms of the tetra­dentate ligand and an O atom of an ethanol ligand form the equatorial plane. The dihedral angle between the mean planes of the two benzene rings is 34.8 (3)°. In the crystal, relatively strong O—H⋯O hydrogen bonds connect the complex and ethanol solvent mol­ecules into alternating centrosymmetric R 2 2(8) and R 4 4(16) ring motifs, forming chains along [100]. Weak inter­molecular C—H⋯O hydrogen bonds are also present.

Synthesis, crystal structure, DNA interaction and cytotoxicity of a dinuclear nickel(II) complex with 5,7-dichloro-8-hydroxylquinoline

A new nickel(II) complex with 5,7-dichloro-8-hydroxylquinoline (H–ClQ), [NiCl(ClQ)(H–ClQ)(μ-Cl)Ni(ClQ)(CH3CH2OH)(H–ClQ)]·CH3COCH3 (1), was synthesized and characterized. In solid state, 1 is consisted of a dinuclear nickel(II) complex and one acetone solvent molecule. Two Ni(II) atoms are chelated by two bidentate 5,7-dichloro-8-hydroxylquinolines and coordinated by one terminal Cl atom or ethanol ligand and one μ-Cl in a distorted octahedral coordination environment. The ESI-MS result shows that the μ-Cl bridge is easily broken in solution to give mononuclear species (omitted as ClQ–Ni complex). The IC50 values of 1 for the inhibition of the proliferation of BEL7404, SGC7901 and MCF-7 tumor cells are 13.0±2.1, 15.9±5.3, and 29.8±9.5μM, respectively, which exhibit significantly enhanced cytotoxicity comparing with free H–ClQ and NiCl2. The binding properties of ClQ–Ni complex to DNA were investigated by UV–Vis, fluorescence, CD spectroscopy, viscosity and agarose gel electrophoresis. The results indicate that intercalation is the most probable binding mode for ClQ–Ni complex to DNA. The ClQ–Ni complex exhibits potent TOPO I inhibition activity at 50μM.

Persistent adult zebrafish behavioral deficits results from acute embryonic exposure to gold nanoparticles

As the number of products containing nanomaterials increase, human exposure to nanoparticles (NPs) is unavoidable. Presently, few studies focus on the potential long-term consequences of developmental NP exposure. In this study, zebrafish embryos were acutely exposed to three gold NPs that possess functional groups with differing surface charge. Embryos were exposed to 50μg/mL of 1.5nm gold nanoparticles (AuNPs) possessing negatively charged 2-mercaptoethanesulfonic acid (MES) or neutral 2-(2-(2-mercaptoethoxy)ethoxy)ethanol (MEEE) ligands or 10μg/mL of the AuNPs possessing positively charged trimethylammoniumethanethiol (TMAT). Both MES- and TMAT–AuNP exposed embryos exhibited hypo-locomotor activity, while those exposed to MEEE–AuNPs did not. A subset of embryos that were exposed to 1.5nm MES- and TMAT–AuNPs during development from 6 to 120h post fertilization was raised to adulthood. Behavioral abnormalities and the number of survivors into adulthood were evaluated at 122days post fertilization. We found that both treatments induced abnormal startle behavior following a tap stimulus. However, the MES–AuNPs exposed group also exhibited abnormal adult behavior in the light and had a lower survivorship into adulthood. This study demonstrates that acute, developmental exposure to 1.5nm MES- and TMAT–AuNPs, two NPs differing only in the functional group, affects larval behavior, with behavioral effects persisting into adulthood.

Synthesis and structural characterization of dinuclear complexes of trivalent aluminum, gallium, indium and chromium derived from pyrazole-2-ethanol

The reaction of 1-(2-hydroxyethyl)-3,5-dimethylpyrazole ( HL) with anhydrous metal(III) halides (M = Al, Ga, In and Cr) results in the isolation of four novel dinuclear complexes [Al( μ- L)Cl 2] 2 ( 1), [Ga( μ- L)Cl 2] 2 ( 2), [In( μ- L)Br 2(H 2O)] 2·2thf ( 3) and [Cr( μ- L)Cl 2(H 2O)] 2·1.5thf ( 4) in good yields. The new complexes have been characterized with the aid of analytical and spectroscopic studies. A single crystal X-ray structure determination in each case confirms the dimeric structure for all the complexes in the solid-state. The pyrazole ethanol ligand binds to the metal through both pyrazole nitrogen and bridging alkoxide oxygen terminals with the formation of a central M 2O 2 core involving the ethoxide anion. The metal(III) center is pentacoordinated in compounds 1 and 2, while it is hexacoordinated in compounds 3 and 4.

Bis[2-(2-aminoethylamino)ethanol]copper(II) dinitrate

In the title compound, [Cu(C4H12N2O)2](NO3)2, the central CuII atom has a distorted octa­hedral coordination geometry and is surrounded by four N atoms and two O atoms from the two inversion-related 2-(2-amino­ethyl­amino)­ethanol ligands. In the crystal, mol­ecules are held together by inter­molecular O—H⋯O and N—H⋯O hydrogen bonds, leading to the formation of a three-dimensional network.

Electronic Spectra and Photochemistry of Coordinated Astaxanthin

Astaxanthin (AXT) is a natural carotenoid which provides colorations to numerous living species such as salmon. Owing to its chelate function deprotonated astaxanthin (axt−) should be easily attached to metal ions. The complex RhIII(phpy)2(axt) with phpy− = deprotonated 2-phenylpyridine was prepared, and its electronic spectra and photochemistry were examined and compared to that of free AXT. Although different in detail, the spectra and photochemistry of AXT and Rh(phpy)2(axt) show common features such as fluorescence and photoisomerization of the axt− ligand in ethanol as solvent. In CH2Cl2 free AXT as well as the complex undergo photooxidation owing to the reducing property of astaxanthin as an antioxidant.

Structural insight into repeated-rhomboid coordination polymers from 4,4′-dithiodipyridine and zinc nitrate

Reaction of Zn(NO3)2·6H2O with the bent bridging ligand 4,4′-dithiodipyridine (dtdp), showing axial chirality, in the presence of the chelating 1,10-phenanthroline (phen) ligand in ethanol yielded [{Zn(μ-dtdp)2(H2O)2}(NO3)2·2C2H5OH·2H2O] n (1). In 1, Zn2+ ions are linked by two dtdp ligands of opposite chirality into a one-dimensional coordination polymer of the repeated-rhomboid type; the phen co-ligand was not encountered in the crystal. Pseudo-symmetry of the lattice is discussed for 1. Reaction of Zn(NO3)2·6H2O and dtdp in an ethanol/water mixture in absence of phen led to the known repeated-rhomboid coordination polymer [{Zn(NO3)(μ-dtdp)2(H2O)}NO3·4H2O] n (2), the crystal structure of which was redetermined at 110 K. At low temperature, the nitrato-κO ligand in one axial position of Zn2+ was found to be non-disordered as distinct from the room temperature structure (Horikoshi and Mikuriya, Cryst Growth Des 5:223–230, 2005). The Zn2+ ions in 2 are joined by two dtdp ligands of the same chirality.

Pyrrole Macrocyclic Ligands for Cu-Catalyzed Asymmetric Henry Reactions

New chiral perazamacrocycles containing four pyrrole rings have been synthesized by the [2+2] condensation of (R,R)-diaminocyclohexane and 5,5'-(alkane-2,2-diyl)bis(1H-pyrrole-2-carbaldehydes). These macrocycles, differing for the alkyl/aryl meso-substituents, were used as ligands in the copper-catalyzed Henry reactions of aromatic and aliphatic aldehydes with nitroalkanes. In the optimized experimental conditions, the condensations of nitromethane and aromatic and aliphatic aldehydes in the presence of catalytic amounts of copper diacetate and methyl-substituted macrocyclic ligand (2:1 ratio) in ethanol at room temperature provided products often with high enantiomeric excesses (up to 95% ee). The positive influence of the macrocyclic structure on the efficiency/enantioselectivity of the catalytic system was demonstrated by comparison with the outcomes of Henry reactions performed using analogous macrocyclic ligands (trianglamines) and open-chain ligands derived from (R,R)-diaminocyclohexane.

Synthesis and structural characterization of iron complexes with 2,2,2-tris(1-pyrazolyl)ethanol ligands: Application in the peroxidative oxidation of cyclohexane under mild conditions

The reactions of FeCl 2.2H 2O and 2,2,2-tris(1-pyrazolyl)ethanol HOCH 2C(pz) 3 ( 1) (pz = pyrazolyl) afford [Fe{HOCH 2C(pz) 3} 2][FeCl 4]Cl ( 2), [Fe{HOCH 2C(pz) 3} 2] 2[Fe 2OCl 6](Cl) 2·4H 2O ( 3·4H 2O), [Fe{HOCH 2C(pz) 3} 2][FeCl{HOCH 2C(pz) 3}(H 2O) 2] 2(Cl) 4 ( 4) or [Fe{HOCH 2C(pz) 3} 2]Cl 2 ( 5), depending on the experimental conditions. Compounds 1– 5 were isolated as air-stable crystalline solids and fully characterized, including ( 1– 4) by single-crystal X-ray diffraction analyses. The latter technique revealed strong intermolecular H-bonds involving the OH group of the scorpionate 2 and 3 giving rise to 1D chains which, in 3, are further expanded to a 2D network with intercalated infinite and almost plane chains of H-interacting water molecules. In 4, intermolecular π⋯π interactions involving the pyrazolyl rings are relevant. Complexes 2– 5 display a high solubility in water (S 25 °C ca. 10–12 mg mL −1), a favourable feature towards their application as catalysts (or catalyst precursors) for the peroxidative oxidation of cyclohexane to cyclohexanol and cyclohexanone, with aqueous H 2O 2/MeCN, at room temperature (TON values up to ca. 385).

Bis[2-(pyridin-2-yl)ethanol-κ2N,O]bis(thiocyanato-κN)nickel(II)

In the title complex, [Ni(NCS)2(C7H9NO)2], the NiII atom is in a distorted octa­hedral coordination environment defined by two N atoms of the two thio­cyanate ions and by the N and O atoms of the two chelating 2-(pyridin-2-yl)ethanol ligands. The complex mol­ecule is located around a crystallographic inversion center. In the crystal, mol­ecules are connected into a two-dimensional polymeric structure parallel to (100) by O—H⋯S hydrogen bonds.

Novel Copper(II) Complexes of N-Phenylanthranilic Acid Containing Ethanol and Hydroxo Ligands

The complexes, tetra-μ-[2-(phenylamino)benzoato](O,O′)-bis[(ethanol)copper(II)] (1) and di-μ-[2-(phenylamino)benzoato](O,O′)-bis[(hydroxo)copper(II)] (2), were synthesized by the reaction of N-phenylanthranilic acid and CuCl2·2H2O in an ethanol water mixture. In complex 1, each Cu(II) atom, which is in a slightly distorted square pyramidal environment, is coordinated equatorially by four N-phenylanthranilate O-atoms and axially by the ethanol O-atoms. In complex 2, [Cu2(C6H5NHC6H4COO)2(OH)2], each Cu(II) atom, which is in tetrahedral environment, is coordinated by two N-phenylanthranilate O-atoms and hydroxo ligands. The crystal structure (monoclinic, P21/c space group) of complex 1 comprises a dinuclear [Cu2(C6H5NHC6H4COO)4(CH3CH2OH)2] species and the dimer is located on a crystallographic inversion centre. The Cu(II) ions, 2.591(2) A apart, are bridged by the carboxylate groups of four N-phenylanthranilate ligands. The complex molecules show three-dimensional supramolecular networks by O–H···O, C–H···O and C–H···π interactions.

Structural Characterization and Theoretical Calculations of cis‐Dioxo(N‐salicylidene‐2‐aminophenolato)(ethanol)molybdenum(VI) Complexes MoO2(SAP)(EtOH) (SAP = N‐salicylidene‐2 aminophenolato)

AbstractThe crystal structure of MoO2(SAP)(EtOH) is reported for the first time. The compound crystallizes in the monoclinic crystallographic system (P21/n, a = 11.0923(3) Å, b = 6.9590(2) Å, c = 19.4499(5) Å, β = 94.458(1)°, V = 1496.82(7) Å3, Z = 4). The molybdenum atom adopts a distorted octahedral arrangement with cis Mo=O bonds, typical for cis‐dioxomolybdenum(VI) complexes. The ethanol ligand is situated trans to one oxido ligand. Theoretical calculations in the gas phase were performed to examine the relative stability of MoO2(L)(EtOH) and the [MoO2(L)]2 dimeric form (L = SAP, SAE).

Trans-Bis(2-benzoylbenzoato-κO1)bis(ethanol-κO)bis(1H-imidazole-κN3)nickel(II)

In the title centrosymmetric mononuclear nickel(II) complex, [Ni(C14H9O3)2(C3H4N2)2(CH3CH2OH)2], the central NiII ion lies on an inversion centre and is octa­hedrally coordinated. The equatorial plane is formed by two O atoms from two symmetry-related 2-benzoyl­benzoate ligands and two N atoms from two symmetry-related imidazole ligands, whereas the axial positions are occupied by two O atoms from two ethanol ligands. Intramolecular O---H...O hydrogen bonds stabilize this arrangement. The mol­ecules are linked into chains running along the b axis by N—H⋯O hydrogen bonds.

Catena-Poly[[(ethanol-κO)sodium(I)]-di-μ-aqua-[(rac-2′-hydroxy-1,1′-binaphthyl-2-yl phosphato-κO)sodium]-tri-μ-aqua

The asymmetric unit of the polymeric title compound, [Na2(C20H13O5P)(C2H6O)(H2O)5]n, consists of two NaI ions, one 2′-hydr­oxy-1,1′-binaphthyl-2-yl phosphate anion, one ethanol ligand and five water molecules of crysallization. Each NaI ion has a distorted octa­hedral coordination geometry. The phosphate anion coordinates to one NaI ion and the ethanol mol­ecule coordinates to the other. The five water mol­ecules bridge the NaI ions, forming an inorganic chain structure along the b axis. The chains are connected by O—H⋯O hydrogen bonds into an organic–inorganic hybrid layer parallel to (001).

(Ethanol-κO)[2-(4-hydroxyphenyl)quinoline-4-carboxylato-κO]triphenyltin(IV)

The Sn atom in the title mol­ecule, [Sn(C6H5)3(C16H10NO3)(C2H6O)], shows a trans-C3SnO2 trigonal bipyramidal coord­in­ation. Adjacent mol­ecules are linked by O—H⋯O and O—H⋯N hydrogen bonds into a two-dimensional array parallel to (100). The ethanol ligand is disordered, with two sites of equal occupancy being resolved for the ethyl group.

Tris(ethanol-κO)tris(picrato-κ2O1,O2)lanthanum(III) tri-2-pyridylamine solvate

The title compound, [La(C6H2N3O7)3(C2H6O)3]·C15H12N4, has two mol­ecular building blocks, namely the neutral mononuclear adduct of lanthanum picrate with ethanol [i.e. La(pic)3:EtOH (1:3); La(pic)3 = lanthanum picrate and EtOH = ethanol] and the oligodentate aromatic nitro­gen base tri-2-pyridylamine (tpa). The asymmetric unit contains two formula units. The compound was prepared during an investigation of the stereochemistry of lanthanoid picrate complexes with O-donor ligands. The metal–ligand adduct adopts a nine-coordinate tricapped trigonal-prismatic metal atom environment. The stereochemical arrangement of the ligands about the metal core is typical of a fac-isomer with stoichiometry M(bidentate)3(monodentate)3. Face-to-face hydrogen bonds are found between the tpa mol­ecule and the ethanol ligands. One ethanol ligand is disordered over two positions, with site occupancy factors of ca 0.7 and 0.3. The oxygen atoms of a nitro group are also disordered over two positions; the site occupancy factors are ca 0.6 and 0.4.

8-Quinolinolato complexes of ruthenium(II) and (III)

Reduction of RuQ 3 ( 1a, Q = 8-quinolinolato) with Zn/Hg in the presence of various π-acceptor ligands in ethanol affords RuQ 2L 2 (L 2 = (dimethylsulfoxide) 2 ( 2); (4-picoline) 2 ( 3); N, N′-dimethyl-1,4-diazabuta-1,3-diene, dab ( 4); cyclooctadiene, COD ( 5); norborna-2,5-diene, nbd ( 6)). Compound 6 is isolated as an equimolar mixture of cis, trans ( 6a) and trans, cis ( 6b) isomers, which can be separated by column chromatography. DFT calculations have been performed on 6a and 6b. Oxidation of 3 and 6b affords the corresponding ruthenium(III) species 7 and 8, respectively. The structures of 2, 3, 4 and 6 have been determined by X-ray crystallography.

Bis[2-(ethylamino)ethanol-κ2N,O]bis(saccharinato-κN)cadmium(II)

In the centrosymmetric title complex, [Cd(C7H4NO3S)2(C4H11NO)2], the CdII ion is coordinated by two saccharinate (sac) anions and two N,O-bidentate 2-(ethyl­amino)ethanol ligands, displaying a distorted octa­hedral coordination. Pairs of mol­ecules are doubly bridged by O—H⋯O hydrogen bonds and these dimers are further linked by weak C—H⋯π(sac) inter­actions.

Bis{2-[(3,5-dibromo-2-oxidophenyl)methylamino]ethanol-κ3O,N,O′}nickel(II)

In the title centrosymmetric complex, [Ni(C9H10Br2NO2)2], the NiII ion is chelated by two 2-[(3,5-dibromo-2-oxidophen­yl)methyl­amino]ethanol ligands in a slightly distorted octa­hedral geometry. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds connect mol­ecules into one-dimensional chains, and there are short inter­molecular Br⋯Br contacts of 3.592 (1) A.

Complexes of Co(II), Ni(II) and Cu(II) with lapachol

Complexes of naturally occurring hydroxynaphtho-quinone, lapachol (2-hydroxy-3(3-methyl-2-buthenyl)-1,4-naphthoquinone = HL) with Co(II), Ni(II) and Cu(II) have been prepared by reaction of the corresponding acetates with the ligand (HL) in ethanol. The molecular and crystal structures were determined for [CoL 2(EtOH) 2] ( 1), [NiL 2(EtOH) 2] ( 2), and [CuL 2(py) 2] ( 3). In all cases the deprotonated lapachol behaves as chelating bidentate ligand. The complexes were also characterized by elemental analyses, cyclic voltammetry, and FAB-MS.