Perchlorate Hexahydrate Research Articles

Oximato bridged dinuclear copper(II) complexes: Synthesis, crystal structure, magnetic, thermal, electrochemical aspects and BVS analysis

Reactions of the Schiff-base ligand, 2-hydroxyimino-3-(2-hydrazonopyridyl)-butane (LH) with copper(II) perchlorate hexahydrate and copper(II) nitrate trihydrate in 1:1molar proportion in methanol give rise respectively to Cu2L2(ClO4)2 (1a) and Cu2L2(NO3)2 (1b) in substantial yields. The complexes have been characterized by C, H and N microanalyses, copper estimation, ESI-MS, FT-IR, UV–Vis spectra, molar electric conductivity and room temperature magnetic susceptibility measurements. The X-ray crystal structures of both 1a and 1b have been determined. The structures reveal that both the complexes are oximato bridged dinuclear Cu(II) assemblies. The electrochemical studies of 1a and 1b show Cu(II) to Cu(III) oxidation in methanol. The thermal behavior of the nitrate analog, 1b, has also been forwarded to delve into the structure. Bond-Valence Sum (BVS) method of analyses was also performed to assign the oxidation state for each copper center both in 1a and 1b.

A molecular butterfly: Self-assembly of an imidazolate bridged tetranuclear nickel(II) compound from Ni(II) and 3-(4-methylimidazol-5-yl)methylene-hydrazonobutan-2-one oxime

Reaction of the Schiff-base ligand, 3-(4-methylimidazol-5-yl)methylenehydrazonobutan-2-one oxime (H2L) with nickel(II) perchlorate hexahydrate in 1:1 molar proportion in methanol gives rise to a tetranuclear nickel(II) compound, Ni4L4 (1) in moderate yield. The compound has been characterized by C, H, N microanalyses, FT-IR, UV–Vis spectra and room temperature magnetic susceptibility measurements. The X-ray crystal structure of the title compound has been determined. The structure reveals that it is an imidazolate bridged neutral tetranuclear nickel(II) compound. The nickel(II) centers in 1 adopt a rare ‘butterfly-like’ topology. The compound crystallizes in the monoclinic space group P21/c with a=17.648 (4), b=23.209 (5), c=14.418 (3) Å, β=108.708 (2)°, V=5593 (2) Å3 and Z=4. Individual nickel(II) center is in square-planar ‘N4’ coordination chromophore. Electrochemical studies show Ni(II) to Ni(III) oxidation along with Ni(II) to Ni(I) reduction in dichloromethane solution. Bond-Valence Sum (BVS) model calculation was performed to assign the oxidation state of each nickel center in 1.

Methanol[1-(methoxymethanimidoyl)-2-(pyridin-2-ylmethyl)guanidine]bis(perchlorato)copper(II)

The title complex, [Cu(ClO(4))(2)(C(9)H(13)N(5)O)(CH(3)OH)], was synthesized from a methanolysis reaction of N-(methylpyridin-2-yl)cyanoguanidine (L(3)) and copper(II) perchlorate hexahydrate in a 1:1 molar ratio. The Cu(II) ion is six-coordinated by an N(3)O(3) donor set which confers a highly distorted and asymmetric octahedral geometry. Three N-donor atoms from the chelating 1-(methoxymethanimidoyl)-2-(pyridin-2-ylmethyl)guanidine (L(3m)) ligand and one O atom from the methanol molecule define the equatorial plane, with two perchlorate O atoms in the apical sites, one of which has a long Cu-O bond of 2.9074 (19) Å. The dihedral angle between the five- and six-membered chelate rings is 8.21 (8)°. Two molecules are associated into a dimeric unit by intermolecular N-H...O(perchlorate) hydrogen bonds. Additionally, the weakly coordinated perchlorate anions also link adjacent [Cu(ClO(4))(2)(L(3m))(CH(3)OH)] dimers by hydrogen-bonding interactions, resulting in a two-dimensional layer in the (100) plane. Further C-H...O hydrogen bonds link the two-dimensional layers along [100] to generate a three-dimensional network.

Facile Synthesis of Bis(indolyl)alkanes Catalyzed by Cu(ClO4)2.6H2O Under Solvent Free Conditions

Copper perchlorate hexahydrate is found to be an efficient catalyst for the electrophilic substitution of indole with carbonyl compounds to prepare bis(indolyl)methane derivatives without solvent in excellent yield at room temperature. Keywords: Bis(Indolyl)methanes, carbonyl compounds, Cu(ClO4)2.6H2O, indole, hexahydrate, perchlorate, Copper, alkanes, diindolylmethane, fluoroboric acid

Effect of Nitrate, Perchlorate, and Water on Uranyl(VI) Speciation in a Room-Temperature Ionic Liquid: A Spectroscopic Investigation

Room-temperature ionic liquids form potentially important solvents in novel nuclear waste reprocessing methods, and the solvation, speciation, and complexation behaviors of lanthanides and actinides in these solvents are of great current interest. In the study reported here, the coordination environment of uranyl(VI) in solutions of the room-temperature ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][Tf(2)N]) containing perchlorate, tetrabutylammonium nitrate, and water was investigated using Raman, ATR-FTIR, and NMR spectroscopies in order to better understand the role played in uranyl(VI) solution chemistry in room-temperature ionic liquids by water and other small, weakly complexing ligands. The (2)H NMR chemical shift for water in a solution of uranyl perchlorate hexahydrate in [EMIM][Tf(2)N] appears at 6.52 ppm, indicating that water is coordinated to uranyl(VI). A broad ν(OH) stretching mode at 3370 cm(-1) in the ATR-FTIR spectrum shows that this coordinated water is engaged in hydrogen bonding with water molecules in a second coordination sphere. A significant upfield shift in the (2)H NMR signal for water and the appearance of distinct ν(as)(HOH) (at 3630 cm(-1)) and ν(s)(HOH) (at 3560 cm(-1)) vibrational bands in the ATR-FTIR spectra show that coordinated water is displaced by nitrate upon formation of the UO(2)(NO(3))(2) and UO(2)(NO(3))(3)(-) complexes. The Raman spectra indicate that perchlorate complexed to uranyl(VI) is also displaced by nitrate. Our results indicate that perchlorate and water, though weakly complexing ligands, do have a role in uranyl(VI) speciation in room-temperature ionic liquids and that Raman, infrared, and NMR spectroscopies are valuable additions to the suite of tools currently used to study the chemical behavior of uranyl(VI)-ligand complexes in these solvents.

Synthesis and Crystal Structure of [Cu(BDBPH)(ClO4)2] (BDBPH = Butane-2,3-dione bis(2′-pyridylhydrazone)

Butane-2,3-dione bis(2′-pyridylhydrazone) (BDBPH), a Schiff-base condensate, was synthesized by 1:2 mol ratio condensation of butane-2,3-dione with 2-hydrazino pyridine in dehydrated methanol. BDBPH has been characterised by C, H and N microanalyses, FT-IR, 1H NMR and UV–Vis spectra. Reaction of 1:1 stoichiometric proportion of BDBPH with copper(II)perchlorate hexahydrate in methanol affords a mononuclear copper(II) complex, [Cu(BDBPH)(ClO4)2] (1). 1 crystallizes in the monoclinic space group P $$ \overline{1} $$ with a = 8.4230(2), b = 9.7869(3), c = 12.3508(3) A, α = 103.784(2), β = 90.900(2), γ = 94.906(2)°, V = 984.51(5) A3 and Z = 2. The copper(II) compound is octahedral and one-electron paramagnetic. Bond Valence Sum (BVS) model calculation was also performed to assign the oxidation number of the copper center. The X-ray crystal structure (1) of the complex copper(II) with butane-2,3-dione bis(2′-pyridylhydrazone) (BDBPH) reveals that the complex is mononuclear. The Jahn–Teller distorted octahedral copper(II) compound is one-electron paramagnetic.

An oxamato bridged trinuclear copper(II) complex: Synthesis, crystal structure, reactivity, DNA binding study and magnetic properties

A linear tri-nuclear oxamato bridged copper(II) complex [Cu3(pba)(dpa)2(H2O)(ClO4)](ClO4)·H2O (1) (pbaH4=1,3-propanediylbis(oxamic acid), dpa=2,2′-dipyridylamine) was isolated from the reaction mixture of Na2[Cu(pba)]·3H2O, copper perchlorate hexahydrate and dipyridylamine in methanol. On reaction with dpa or DMF in basic medium (KOH) at ambient temperature complex 1 changed to dinuclear oxalate bridged copper(II) derivatives, [Cu2(μ-C2O4)(dpa)4](ClO4)2 (2) and [Cu2(μ-C2O4)(dpa)2(DMF)2](ClO4)2 (3), respectively. The complexes 1, 2 and 3 have been characterized by physicochemical and spectroscopic tools, and also by the X-ray single crystal analysis. The hydrolysis of 1 in basic medium and thermo-gravimetric analysis has been studied. Absorption and emission spectral studies showed that complex 1 interacts with calf thymus-DNA (CT-DNA) with a binding constant (Kb) of 4.01×104M−1 and linear Stern–Volmer quenching constant (Ksv) of 6.9×104. A strong anti-ferromagnetic interaction with a coupling constant JCuCu of 320.0±0.3cm−1 was observed from the study of magnetic behavior of complex 1 in the temperature range of 2–300K. Electrochemical equivalency of three copper(II) ions in 1 was identified by getting only one quasi reversible cyclic voltammogram.

Synthesis of 2,3,4,11b-Tetrahydro-1H-pyridazino[6,1-a]isoquinolines via the Three-Component Reaction of 2-Alkynylbenzaldehydes, a Sulfonohydrazide and Dimethyl Cyclopropane-1,1-dicarboxylate

A three-component reaction of 2-alkynylbenzaldehydes, a sulfonohydrazide and dimethyl cyclopropane-1,1-dicarboxylate, co-catalyzed by silver(I) triflate and nickel(II) perchlorate hexahydrate, is described, which affords 2,3,4,11b-tetrahydro-1H-pyridazino[6,1-a]isoquinolines in moderate to good yields. A possible reaction pathway that proceeds via a tandem 6-endo-cyclization and [3+3] cycloaddition sequence is proposed.

Synthesis of β-Amino Alcohols from Terminal Epoxy Fatty Acid Methyl Ester

Fats and oils are renewable feedstock that can be treated chemically or enzymatically to derive materials that often act as a replacement for petroleum-derived materials. Long-chain fatty epoxides can be transformed to several chemical derivatives. There has been increasing interest in using these substances as intermediates in the production of new biobased industrial materials. In the present work, renewable methyl 10,11-epoxyundecanoate were reacted with various cyclic, aliphatic, and aromatic amines in the presence of zinc(II) perchlorate hexahydrate as a Lewis acid catalyst under solvent-free conditions, to derive several new β-amino alcohols in a regioselective manner.

Copper Perchlorate Hexahydrate: An Efficient Catalyst for the Green Synthesis of Polyhydroquinolines under Ultrasonication.

Copper perchlorate hexahydrate as an efficient catalyst was used for the synthesis of polyhydroquinolines by four-component condensation reaction of aldehyde, ethyl acetoacetate, dimedone, and ammonium acetate in excellent yields and short reaction times at room temperature under ultrasound irradiation. This novel synthetic method is especially favoured because it provides a synergy between copper perchlorate hexahydrate and ultrasound irradiation which offers the advantages of high yields, short reaction times, simplicity, and easy workup compared to the conventional methods reported in the literature.

Synthesis, Crystal Structure and Spectroscopic Properties of an Oximato Bridged Cu(II) Dimer

Schiff-base condensation of a equimolar proportion of diacetyl-monoxime monohydrazone and 1-methylimidazole-2-carboxaldehyde in methanol gives rise to the imidazole azine, 3-(1-methylimidazol-2-yl)methylenehydrazonobutan-2-one oxime(HL). Reaction of 1:1 stoichiometric proportion of HL with copper(II)perchlorate hexahydrate in methanol yields a dimeric oximato bridged copper compound, [Cu2L2(H2O)2](ClO4)2 (1). The compound is characterized by C, H and N analyses, FT-IR, ESI–MS, conductivity measurement, UV–Vis spectra and X-ray single crystal diffraction. The title compound (1) crystallizes in the monoclinic space group P21/c with a = 6.8533 (8), b = 18.413 (2), c = 11.7399 (14) A, β = 93.685 (2)°, V = 1478.4 (3) A3 and Z = 2. The geometry around each copper center is distorted square pyramidal. The copper(II) dimer shows antiferromagnetic interaction mediated by symmetric disposition of oximato groups. A dimeric oximato bridged copper compound, [Cu2L2(H2O)2](ClO4)2 (1), with antiferromagnetic interaction was characterized by C, H and N analyses, FT-IR, ESI–MS, conductivity measurement, UV–Vis spectra and X-ray single crystal diffraction.

Structure and Heme-Independent Peroxidase Activity of a Fully-Coordinated Mononuclear Mn(II) Complex with a Schiff-Base Tripodal Ligand Containing Three Imidazole Groups

New complex [Mn(II)H1.5L]2[Mn(II)H3L]2(ClO4)5·3H2O (1), where H3L is tris{2-(4-imidazolyl)methyliminoethyl} amine (imtren), has been prepared by reacting manganese(II) perchlorate hexahydrate with the imtren ligand in methanol. X-ray crystallographic study revealed that the imtren ligand hexadentately binds to Mn(II) ion through the three Schiff-base imine N atoms and three imidazole N atoms with a distorted octahedral geometry, and the apical tertiary amine N atom of the ligand pseudo-coordinates to Mn(II), forming overall a pseudo-seven coordination environment. The hydrogen-bonds between imidazole and imidazolate of [Mn(II)H1.5L] 0.5+ complex ions are extended to build a 2D puckered network with trigonal voids. [Mn(II)H3L] 2+ complex ions constitutes another extended 2D puckered layer without hydrogen bonds. Two layers are wedged each other to constitute overall stack of the crystal. Peroxidase activity of complex 1 was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of complex 1. Generation of ABTS

ChemInform Abstract: Bisoxazoline and Bioxazoline Chiral Ligands Bearing 4-Diphenylmethyl Shielding Substituents. Diels-Alder Reaction of Cyclopentadiene with 3-Acryloyl-2-oxazolidinone Catalyzed by the Aqua Nickel(II) Complex.

Enantiopure 2-amino-3,3-diphenyl-1-propanol has been synthesized by the hidantoin route starting from diphenylacetaldehyde, followed by subsequent functional group transformations and optical resolution by a chiral HPLC. This amino alcohol can be converted into two new chiral ligands: 4,4′-bis(diphenylmethyl)-2,2′-bioxazoline and 2,2′-isopropylidenebis(4-diphenylmethyloxazoline), and further to complexes with copper(II) trifluoromethanesulfonate and nickel(II) perchlorate hexahydrate. The nickel(II) aqua complex derived from the bisoxazoline effectively catalyzes the Diels-Alder reactions of cyclopentadiene with 3-acryloyl-2-oxazolidinone in high endo-selectivities and moderate enantioselectivities through a square planar transition structure.

Properties of Acetylated Wood Prepared at Low Temperature in the Presence of Catalysts

In the presence of catalysts such as sodium acetate, zinc chloride, magnesium perchlorate, and magnesium chloride hexahydrate, acetylation of wood at 75°C was investigated. The results showed that it was possible to endow wood with high dimensional stability at low temperature by a catalyzed acetylation method. In particular, the magnesium chloride–catalyzed acetylation of wood showed very little or no effect on the color change or mechanical property of wood, as contrasted to those of the zinc chloride or magnesium perchlorate–catalyzed treatment, which showed a great effect. In addition, the concentrations of catalysts proved to have an effect on weight percent gain.

Synthesis, crystal structure and magnetism of [Mn(tfbdc)(MeOH)4] (tfbdc = tetrafluoroterephthalate)

[Mn(tfbdc)(MeOH)4] was synthesized by reaction of tetrafluoroterephthalatic acid with manganese(II) perchlorate hexahydrate in methanol. The complex was characterized by elemental analysis, IR spectra, magnetism, and X-ray single crystal structure analysis. This complex crystallizes in the monoclinic system with space group C2/c. Mn(II) has a distorted octahedral geometry coordinated by two oxygens from two tetrafluoroterephthalate (tfbdc) and four MeOH molecules. Each tfbdc ligand bridges two Mn(II) ions in end-to-end fashion, forming a zigzag chain. These chains are connected by hydrogen bonds, forming a 2-D supramolecular network. Magnetic susceptibility data from 300–1.8 K show that there is a weak antiferromagnetic exchange between Manganese(II) ions.

Crystal structure of a two-dimensional Co(II) coordination polymer: [Co(μ-PP)2(SCN)2] n [PP = 2-(pyridine-3-yloxy)pyrazine

Solvothermal reaction (water/methanol) of cobalt perchlorate hexahydrate, sodium thiocyanate and 2-(pyridine-3-yloxy)pyrazine (PP) resulted in the formation of a two-dimensional coordination polymer [Co(μ-PP)2(SCN)2]n. The solid complex has been characterized by elemental analysis and IR spectroscopy; its crystal structure was determined by X-ray crystallography. The complex crystallizes in the monoclinic system, space group P21/n, a = 7.4643(19) A, b = 9.237(2) A, c = 15.540(4) A, β = 94.995(5)°, V = 1067.4(5) A3, Z = 1. In the crystal structure each 2-(pyridine-3-yloxy)pyrazine molecule acts as a bidentate bridging ligand coordinating to two adjacent Co(II) ions with Co...Co separation of 9.5176(18) A to yield a two-dimensional sheet structure in the plane (−1 0 1).

Synthesis and X‐ray Crystal Structure of Bis[oxamide dioximato‐κ2N,N′](oxamide dioxime‐κ2N,N′)cobalt(III) Perchlorate Hexahydrate

AbstractCo(OAc)2 reacts with oxamide dioxime (H2oxado) in water in the presence of ClO4– ions to produce [Co(Hoxado)2(H2oxado)]ClO4·6H2O (1), where Hoxado– is the anion of H2oxado, derived from the deprotonation of one of the two hydroximinic groups, and in which oxidation of CoII to CoIII (in air) had occurred. 1 is the first example of a salt in which the cation, [Co(H2oxado)3]3+, is doubly deprotonated to generate the chiral cation, [Co(Hoxado)2(H2oxado)]+. The central cobalt cation is pseudo‐octahedrally coordinated by six nitrogen atoms. In the solid state, the complex cations form centro‐symmetric dimers via O–H···O bridges. The bulk structure is consolidated by an extended three‐dimensional network of O–H···O and N–H···O bridges that interconnect the ionic constituents and the water molecules.

Chemistry of the binary mixture of 1,10-phenanthroline and zinc perchlorate hexahydrate in methanol and gas phase. Monohydroxo species and tricoordination of zinc and water clusters

ESIMS reveals that methanol solutions of 1:1, 1:2 and 1:3 mixtures of Zn(ClO 4) 2 · 6H 2O and 1,10-phenanthroline (phen) generate [Zn(phen)(OH)] +, [Zn(phen)(H 2O) 4(OH)] +, [Zn(phen) 2(H 2O)(OH)] +and [Zn(phen) 2(H 2O) 4(OH)] + ions in the gas phase. DFT calculations at the B3LYP/LanL2DZ level show that zinc is planar tricoordinate in [Zn(phen)(OH)] + and the cis configuration is more stable than the trans one for the hexacoordinate ion [Zn(phen) 2(H 2O)(OH)] +. DFT calculations also show that the [Zn(phen)(H 2O) 4(OH)] + and [Zn(phen) 2(H 2O) 4(OH)] + ions are actually [Zn(phen)(H 2O)(OH)] + · 3H 2O and [Zn(phen) 2(H 2O)(OH)] + · 3H 2O containing extended motifs of H-bonded water clusters. The aqua species corresponding to the monohydroxo ions are acidic. Their acid dissociations are modeled collectively by equilibrium (see below) where other ligands around Zn are not specified. An attempt is then made to estimate K a Zn - OH 2 2 + ⇆ K a Zn - OH + + H + of various binary mixtures of Zn(ClO 4) 2 · 6H 2O and phen in methanol from solution conductivity. In accordance with the above results, the aqueous solution of [Zn(phen) 3](ClO 4) 2 · C 2H 5OH · H 2O is found to be acidic.

Monomeric complexes of 1,8- bis (isonicotinyloxy)anthracene-9,10-dione

Condensation of two equivalents of isonicotinic acid with 1,8-dihydroxyanthraquinone forms 1,8-bis(isonicotinyloxy)anthracene-9,10-dione (1), a potential bridging diester ligand. Complexation reactions between 1 and Co(II) and Ni(II) perchlorate hexahydrate salts produce 2 : 1 ligand : metal monomeric complexes. One nicotinic nitrogen is bonded to a metal center while the second ‘free’ isonicotinic nitrogen is hydrogen bonded to water molecules, present from the hydrated salts used in the synthesis, ligated to the same metal center.

ChemInform Abstract: Copper Perchlorate Hexahydrate: A Highly Efficient Catalyst for the Cyanosilylation of Aldehydes.

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