Catalytic Applications of Nano‐Fe‐[Phenyl‐Salicylaldimine‐Methylpyranopyrazole]Cl2 as a Schiff Base Complex and Nanostructured Catalyst for the Synthesis of Hexahydroquinolines

By the four‐component condensation reaction of benzaldehyde with ethyl acetoacetate, malononitrile, and hydrazine hydrate using FeCl₂, a pyranopyrazole derivative was synthesized and then reacted with salicylaldehyde to give nano‐Fe‐[phenyl‐salicylaldimine‐methylpyranopyrazole]Cl₂ (nano‐[Fe‐PSMP]Cl₂). The prepared nano‐Schiff base complex was successfully used as an efficient catalyst for the synthesis of hexahydroquinolines.     

Mn‐[4‐Chlorophenyl‐Salicylaldimine‐Methylpyranopyrazole]Cl2 as a Novel Nanostructured Schiff Base Complex and Catalyst

Mn‐[4‐chlorophenyl‐salicylaldimine‐methylpyranopyrazole]Cl₂ ([Mn‐4CSMP ]Cl₂) as nano‐Schiff base complex was prepared and fully characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermal gravimetric analysis, derivative thermogravimetry, scanning electron microscopy, energy‐dispersive X‐ray analysis, and UV–vis spectroscopy. The reactivity of nano‐[Mn‐4CSMP ]Cl₂ as a catalyst was tested on the tandem cyclocondensation–Knoevenagel condensation–Michael reaction between phenylhydrazine and ethyl acetoacetate with various aromatic aldehydes to give 4,4′‐(arylmethylene)‐bis‐(3‐methyl‐1‐phenyl‐1H ‐pyrazol‐5‐ol)s derivatives.     

Nano‐Zn[2‐boromophenylsalicylaldiminemethylpyranopyrazole]Cl2 as a novel nanostructured Schiff base complex and catalyst for the synthesis of pyrano[2,3‐d]pyrimidinedione derivatives

Nano‐Zn[2‐boromophenylsalicylaldiminemethylpyranopyrazole]Cl₂ (nano‐[Zn‐2BSMP]Cl₂) as a novel nanostructured Schiff base complex was prepared and characterized using several techniques. Nano‐[Zn‐2BSMP]Cl₂ was used as an effective catalyst for the preparation of some pyrano[2,3‐d]pyrimidinedione derivatives by the multicomponent reaction of malononitrile, aryl aldehydes and barbituric acid derivatives. The novelty and efficiency of nano‐[Zn‐2BSMP]Cl₂ as a catalyst, in comparison with some other reported catalysts, for this synthetic transformation are the main features of this work.     

Nano–Mn‐[4‐nitrophenyl‐salicylaldimine‐methyl pyranopyrazole]Cl2 as a new nanostructured Schiff base complex and catalyst for the synthesis of hexahydroquinolines

By the reaction of 4‐nitrobenzaldehyde with ethyl acetoacetate, malononitrile and hydrazine hydrate, pyranopyrazole derivative as an active biological compound was synthsized and then reacted with salicylaldehyde and MnCl₂.4H₂O to afford nano‐Mn‐[4‐nitrophenyl‐salicylaldimine‐methyl pyranopyrazole]Cl₂ (nano‐[Mn‐4NSMP]Cl₂) for the first time. The produced Schiff base complex with nanostructured was fully characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG) and scanning electron microscope (SEM) and used it as an efficient catalyst for the preparation of hexahydroquinolines.     

Synthesis of 4‐((2‐hydroxynaphthalen‐1‐yl)(aryl)methyl)‐5‐methyl‐2‐phenyl‐1H‐pyrazol‐3(2H)‐ones using nano‐Zn‐[2‐boromophenyl‐salicylaldimine‐methylpyranopyrazole]Cl2 nanoparticles

Nano‐Zn‐[2‐boromophenyl‐salicylaldimine‐methylpyranopyrazole]Cl₂ (nano‐[Zn‐2BSMP]Cl₂) as a nanoparticle Schiff base complex and a catalyst was introduced for the solvent‐free synthesis of 4‐((2‐hydroxynaphthalen‐1‐yl)(aryl)methyl)‐5‐methyl‐2‐phenyl‐1H‐pyrazol‐3(2H)‐ones by the multicomponent condensation reaction of various aromatic aldehydes, β‐naphthol, ethyl acetoacetate, and phenyl hydrazine at room temperature.     

Synthese und Strukturaufklärung von neuen (Eisencarbonyl)zinkund ‐cadmiumchlorid‐Derivaten

Syntheses and Structure Elucidations of Novel (Ironcarbonyl)zinc and ‐cadmium Chloride Derivatives Reactions of zinc/cadmium chloride with Na₂[Fe(CO)₄] lead to a number of new (iron carbonyl)zinc/cadmium chlorides, wherein the reaction course depends on the used solvent used. In the reaction of ZnCl₂ with Na₂[Fe(CO)₄], three new substances can be prepared. The compound [Zn₂Cl₂Fe(CO)₄(THF)₂] ( 1 ), which consists of neutral polymeres, is formed in THF, the ionic compound [Na(DME)₃][Zn₂Cl₃Fe(CO)₄] ( 2 ) forms in DME, and from a mixture of THF and TMEDA the compound [Zn₂Cl₂Fe(CO)₄(TMEDA)₂] ( 3 ) is obtained as a monomere. Also by using CdCl₂, the reaction with Na₂[Fe(CO)₄] in THF leads to the polymeric compound ([(Cd₄Cl₆)Fe(CO)₄(THF)₅] ( 4 )). Carrying out the reaction in a mixture of toluene and DME leads to the formation of the ionic compound [Na(DME)₃]₂[Cd₆{Fe(CO)₄}₆Cl₂(DME)₂] ( 5 ) in which an annular dianion consisting of twelve metal atoms is found. From an aqueous solution and subsequent work‐up in THF, the compound [Fe(THF)₄(H₂O)₂][Cd₈{Fe(CO)₄}₄Cl₉(THF)₆]₂ ( 6 ) can be prepared which contains an cluster anion that is built of anellated six membered rings.     

Formation and Molecular Structure of an Ion Pair Iron (II) Compound Derived from 2,6‐Bis‐ [1‐(2,6‐dibromophenylimino) ‐ethyl] pyridine and 2‐Acetyl‐6‐[1‐(2, 6‐dibromophenylimino)‐ethyl] pyridine

Two novel tridentate ligands of 2,6‐bis‐[l‐(2,6‐dibromophenylimino) ethyl] pyridine (L₁) and2‐acetyl‐6‐[1‐(2,6‐dibromophenylimino) ethyl] pyridine (L2) have been synthesized. The iron(II) complex of L₁ and L₂ has been characterized with the crystal structure of [Fe(L₁)(L₂)]²⁺ [FeCl₄]² CH₂Cl₂ [monoclinic, P2₁ (#11), a = 1.0562(4), b = 2.0928(4), c = 1.2914(2) nm, β = 100.12°, V = 2.810(1) nm³ D_c = 1.879 g/cm³ and Z = 2].     

Dispersion of Reduced Graphene Oxide in Multiple Solvents with an Imidazolium‐Modified Hexa‐peri‐hexabenzocoronene

An imidazolium‐modified hexa‐peri‐hexabenzocoronene derivative (HBC‐C₁₁‐MIM[Cl^?]) was designed and synthesized as a stabilizer to fabricate reduced graphene oxide (RGO). The resulting RGO/HBC‐C₁₁‐MIM[Cl^?] hybrid shows excellent dispersivity (5.0 mg mL^?1) and stability in water. RGO/HBC‐C₁₁‐MIM[Cl^?] was comprehensively characterized by using atomic force microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, thermogravimetric analysis, and Raman spectroscopy, thus revealing that one HBC‐C₁₁‐MIM[Cl^?] group can stabilize about 178 carbon atoms on the graphene sheets. The obtained hybrid film exhibits a high conductivity of 286 S m^?1. Furthermore, the HBC‐C₁₁‐MIM[Cl^?]‐modified RGO sheets can be readily dispersed in polar organic solvents upon exchange of the hydrophilic Cl^? ions for hydrophobic bis(trifluoromethylsulfonyl) amide (NTf₂^?) ions.     

Bis(N‐acetyltriethylphosphaniminium)‐tetraacetato‐dichloro‐dicuprat(II), [MeC(O)N(H)PEt3]2[Cu2(O2C–Me)4Cl2]

Bis(N‐acetyltriethylphosphaneiminium)‐tetraacetato‐dichloro‐dicuprate(II), [MeC(O)N(H)PEt₃]₂[Cu₂(O₂C–Me)₄Cl₂] The title compound has been prepared by the reaction of Me₃SiNPEt₃ with [Cu₂(O₂C–Me)₄] and MeC(O)Cl in dichloromethane solution to give colourless crystals which include four molecules CH₂Cl₂ per formula unit. The complex is characterized by IR spectroscopy and by a crystal structure determination. [MeC(O)N(H)PEt₃]₂[Cu₂(O₂C–Me)₄Cl₂] · 4 CH₂Cl₂: Space group P2₁/n, Z = 2, lattice dimensions at –70 °C: a = 794.1(1), b = 2356.9(6), c = 1327.3(2) pm; β = 91.00(1)°; R₁ = 0.0597. The structure consists of N‐acetyltriethylphosphaneiminium cations and dianions [Cu₂(O₂C–Me)₄Cl₂]^2– which form an iontriple with N–H…Cl hydrogen bridges.     

Synthesis of regioregular poly(3‐octylthiophene)s via Suzuki polycondensation and end‐group analysis by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Regioregular poly(3‐octylthiophene)s were synthesized through a palladium‐catalyzed Suzuki polycondensation of 2‐(5‐iodo‐4‐octyl‐2‐thienyl)‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane. The effects of the palladium catalyst {tetrakis(triphenylphosphine)palladium(0) [Pd(PPh₃)₄], palladium(II) acetate [Pd(OAc)₂], [1, 1′‐bis(diphenylphosphino)ferrocene]dichloropalladium(II) [Pd(dppf)Cl₂], tris(dibenzylideneacetone)dipalladium(0), or bis(triphenylphosphine)palladium(II) dichloride [Pd(PPh₃)₂Cl₂]} and the reaction conditions (bases and solvents) were investigated. NMR spectroscopy revealed that poly(3‐octylthiophene)s prepared via this route were essentially regioregular. According to size exclusion chromatography, the highest molecular weights were obtained with in situ generated Pd(PPh₃)₄ and tetrakis(tri‐o‐tolylphosphine]palladium(0) {Pd[P(o‐Tol)₃]₄} catalysts or more reactive, phosphine‐free Pd(OAc)₂. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry was used to analyze end groups and allowed the determination of some mechanistic aspects of the Suzuki polycondensation. The polymers were commonly terminated with hydrogen or iodine as a result of deboronation and some deiodination. Pd(PPh₃)₄, Pd(PPh₃)₂Cl₂, and Pd[P(o‐Tol)₃]₄ induced aryl–aryl exchange reactions with the palladium center and resulted in some chains having phenyl‐ and o‐tolyl‐capped chain ends. Pd(dppf)Cl₂ yielded only one type of chain, and it had hydrogen end groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1454–1462, 2005     

Nano n‐propylsulfonated γ‐Al2O3: a new,efficient and reusable catalyst for synthesis of spiro[indoline‐3,4‐pyrazolo[3,4‐e][1,4]thiazepine]diones in aqueous media

Nano n‐propylsulfonated γ‐Al₂O₃ is easily prepared by the reaction of nano γ‐Al₂O₃ with 1,3‐propanesultone. This reagent can be used as an efficient catalyst for the synthesis of spiro [indoline‐3,4‐pyrazolo[3,4‐e][1,4]thiazepine]diones in aqueous media. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be reused and recovered several times. Copyright © 2013 John Wiley & Sons, Ltd.     

Waste to wealth: conversion of nano‐magnetic eggshell (Fe3O4@Eggshell) to Fe3O4@Ca(HSO4)2: cheap,green and environment‐friendly solid acid catalyst

Eggshell is a hazardous waste by European Union regulations, so that discarded thousands of tons per year. To convert waste (eggshell) to wealth (catalyst), nano‐magnetic eggshell was prepared based on the nano‐Fe₃O₄, and then the eggshell was converted to Ca(HSO₄)₂ with organic acid, namely, chlorosulfonic acid. Based on the back titration, 5.18 mmol SO₄H group was loaded per gram of the nano‐structure. Using this method eggshell was converted to cheap, green and environment‐friendly solid acid catalyst. The prepared catalyst (nano‐ Fe₃O₄@Ca(HSO₄)₂) was characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), energy dispersive X‐ray spectroscopy (EDX), field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and thermal gravimetric analysis (TGA). The activity of eggshell waste‐derived catalysts was successfully evaluated in the synthesis of value‐added products, namely indazolo[1,2‐b]‐phthalazinetrione derivatives as a benchmark multicomponent reaction. In addition, design of experiments shows that increase in amount of catalyst (and temperature), boost the reaction yield, especially with steeper slope at higher temperature.     

Novel type of SO3H–functionalized nano‐titanium dioxide as a highly efficient and recyclable heterogeneous nanocatalyst for the synthesis of tetrahydrobenzo[b]pyrans

n ‐Butylsulfonated nano‐titania (n‐TiO₂‐NH‐(CH₂)₄‐SO₃H) as a highly efficient and reusable nanocatalyst was prepared by grafting 2,4‐toluene diisocyanate as a bi‐functional covalent linker onto a nano‐titania support, followed by reduction and then ring opening‐reaction of the synthesized amine with 1,4‐butanesultone. Fourier transform infrared spectroscopy, X‐ray diffraction, field‐emission scanning electron microscopy and thermogravimetric analysis were used to characterize the catalyst. The catalytic activity of n‐TiO₂‐NH‐(CH₂)₄‐SO₃H was evaluated in the synthesis of tetrahydrobenzo[b ]pyrans, which affords high yields. Statistical experimental design was applied as an efficient and powerful method to achieve the optimal conditions for this catalytic reaction leading to high yield. Moreover, the catalyst was recovered and reused at least six times without a significant decrease in catalytic activity.     

Engineering a Cu‐MOF Nano‐Catalyst by using Post‐Synthetic Modification for the Preparation of 5‐Substituted 1H‐Tetrazoles

A new nano scale Cu‐MOF has been obtained via post‐synthetic metalation by immersing a Zn‐MOF as a template in DMF solutions of copper(II) salts. The Cu‐MOF serves as recyclable nano‐catalyst for the preparation of 5‐substituted 1H‐tetrazoles via [3 + 2] cycloaddition reaction of various nitriles and sodium azide in a green medium (PEG). The post‐synthetic metalated MOF were characterized by FT‐IR spectroscopy, powder X‐ray diffraction (PXRD), atomic absorption spectroscopy (AAS), and energy dispersive X‐ray spectroscopy (EDX) techniques. The morphology and size of the nano‐catalyst were determined by field emission scanning electron microscopy (FE‐SEM).     

1‐(2‐Hydroxyethyl)‐3‐nitro‐1, 2, 4‐triazole and its Complexes with Copper(II) Chloride and Copper(II) Perchlorate

1‐(2‐Hydroxyethyl)‐3‐nitro‐1, 2, 4‐triazole (hnt), prepared by alkylation of 3‐nitro‐1, 2, 4‐triazole with 2‐chloroethanol, was found to react with copper(II) chloride and copper(II) perchlorate in acetonitrile/ethanol solutions giving complexes [Cu₂(hnt)₂Cl₄(H₂O)₂] and[Cu(hnt)₂(H₂O)₃](ClO₄)₂, respectively. They are the first examples of coordination compounds with a neutral N‐substituted 3‐nitro‐1, 2, 4‐triazole ligand. 1‐(2‐Hydroxyethyl)‐3‐nitro‐1, 2, 4‐triazole and the obtained complexes were characterized by NMR and IR spectroscopy, X‐ray, and thermal analyses. [Cu₂(hnt)₂Cl₄(H₂O)₂] presents a dinuclear chlorido‐bridged complex in which hnt acts as a chelating bidentate ligand, coordinated to the metal by a nitrogen atom of the triazole ring and an oxygen atom of the nitro group, and the copper atoms are inconsiderably distorted octahedral coordination. [Cu(hnt)₂(H₂O)₃](ClO₄)₂comprises a mononuclear complex cation, in which two nitrogen atoms of two hnt ligands in trans configuration and three water oxygen atoms form a square pyramidal environment around the copper atom, which is completed to an distorted octahedron with a bifurcated vertex due to two additional elongated Cu–O bonds with two nitro groups. In both complexes, Cu–O bonds with the nitro groups may be considered as semi‐coordinated.     

A Red‐Light‐Activated Ruthenium‐Caged NAMPT Inhibitor Remains Phototoxic in Hypoxic Cancer Cells

We describe two water‐soluble ruthenium complexes, [ 1 ]Cl₂ and [ 2 ]Cl₂, that photodissociate to release a cytotoxic nicotinamide phosphoribosyltransferase (NAMPT) inhibitor with a low dose (21 J cm⁻²) of red light in an oxygen‐independent manner. Using a specific NAMPT activity assay, up to an 18‐fold increase in inhibition potency was measured upon red‐light activation of [ 2 ]Cl₂, while [ 1 ]Cl₂ was thermally unstable. For the first time, the dark and red‐light‐induced cytotoxicity of these photocaged compounds could be tested under hypoxia (1 % O₂). In skin (A431) and lung (A549) cancer cells, a 3‐ to 4‐fold increase in cytotoxicity was found upon red‐light irradiation for [ 2 ]Cl₂, whether the cells were cultured and irradiated with 1 % or 21 % O₂. These results demonstrate the potential of photoactivated chemotherapy for hypoxic cancer cells, in which classical photodynamic therapy, which relies on oxygen activation, is poorly efficient.     

Crystal Structures and Luminescent Properties of Two Zinc(II) Coordination Compounds with a β‐Diketonate Derivative Ligand

The β‐diketonate derivative ligand [H₂L = 6‐(3‐hydroxy‐1‐oxo‐3‐pyrryl‐2‐propen‐1‐yl)‐2‐pyridinecarboxylic acid] and its zinc(II) coordination complexes, [Zn(H₂L)Cl₂] · (EtOH)(H₂O) ( 1 ) and [Zn₄(L)₄(H₂O)₂] · 5H₂O ( 2 ), were prepared and characterized by elemental analysis, IR and NMR spectroscopy, and single‐crystal X‐ray diffraction. Complex 1 is a mononuclear structure. Complex 2 is a [2 × 2] grid tetranuclear structure. The luminescent properties of the free ligand H₂L and complexes 1 and 2 in methanol solution were studied.     

Zweikernige Palladium(II)‐, Platin(II)‐ und Iridium(III)‐Komplexe von Bis[imidazol‐4‐yl]alkanen

Dinuclear Palladium(II), Platinum(II), and Iridium(III) Complexes of Bis[imidazol‐4‐yl]alkanes The reaction of bis(1,1′‐triphenylmethyl‐imidazol‐4‐yl) alkanes ((CH₂)_n bridged imidazoles L(CH₂)_nL, n = 3–6) with chloro bridged complexes [R₃P(Cl)M(μ‐Cl)M(Cl)PR₃] (M = Pd, Pt; R = Et, Pr, Bu) affords the dinuclear compounds [Cl₂(R₃P)M–L(CH₂)_nL–M(PR₃)Cl₂] 1 – 17 . The structures of [Cl₂(Et₃P)Pd–L(CH₂)₃L–Pd(PEt₃)Cl₂] ( 1 ), [Cl₂(Bu₃P)Pd–L(CH₂)₄L–Pd(PBu₃)Cl₂] ( 10 ), [Cl₂(Et₃P)Pd–L(CH₂)₅L–Pd(PEt₃)Cl₂] ( 3 ), [Cl₂(Et₃P)Pt–L(CH₂)₃L–Pt(PEt₃)Cl₂] ( 13 ) with trans Cl–M–Cl groups were determined by X‐ray diffraction. Similarly the complexes [Cl₂(Cp*)Ir–L(CH₂)_nL–Ir(Cp*)Cl₂] (n = 4–6) are obtained from [Cp*(Cl)Ir(μ‐Cl)₂Ir(Cl)Cp*] and the methylene bridged bis(imidazoles).     

Assembly,Structures, and Properties of a Series of Metal‐Organic Coordination Polymers Derived from a Semi‐rigid Bis‐pyridyl‐bis‐amide Ligand

Four metal‐organic coordination polymers [Cd(4‐bpcb)_1.5Cl₂(H₂O)] ( 1 ), [Cd(4‐bpcb)_0.5(mip)(H₂O)₂] · 3H₂O ( 2 ), [Co(4‐bpcb)(oba)(H₂O)₂] ( 3 ), and [Ni(4‐bpcb)(oba)(H₂O)₂] ( 4 ) [4‐bpcb = N,N′‐bis(4‐pyridinecarboxamide)‐1, 4‐benzene, H₂mip = 5‐methylisophthalic acid, and H₂oba = 4, 4′‐oxybis(benzoic acid)] were synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction, elemental analyses, IR spectroscopy, powder X‐ray diffraction, and TG analysis. In complex 1 , two Cl^– anions serve as bridges to connect two Cd‐(μ₁‐4‐bpcb) subunits forming a dinuclear unit, which are further linked by μ₂‐bridging 4‐bpcb to generate 1D zigzag chain. Complex 2 shows a 2D 6³ network constructed by [Cd‐mip]_n zigzag chains and μ₂‐bridging 4‐bpcb ligands. Complexes 3 and 4 are isostructural 2D (4, 4) grid networks derived from [M‐oba]_n (M = Co, Ni) zigzag chains and [M‐(4‐bpcb)]_n linear chains. The 1D chains for 1 and the 2D networks for 2 – 4 are finally extended into 3D supramolecular architectures by hydrogen bonding interactions. The roles of dicarboxylates and central metal ions on the assembly and structures of the target compounds were discussed. Moreover, the thermal stabilities, photoluminescent properties, and photocatalytic activities of complexes 1 – 4 and the electrochemical properties of complexes 3 and 4 were investigated.     

Structural Study of Nickel(II), Copper(II), and Palladium(II) Complexes of 2‐Pyridineformamide 3‐Hexamethyleneiminylthiosemicarbazone

Reduction of 2‐cyanopyridine by sodium in the presence of 3‐hexamethyleneiminylthiosemicarbazide produces 2‐pyridineformamide 3‐hexamethyleneiminylthiosemicarbazone, HAmhexim. Complexes with nickel(II), copper(II) and palladium(II) have been prepared and the following complexes structurally characterized: [Ni(Amhexim)OAc], [{Cu(Amhexim)}₂C₄H₄O₄]·2DMSO·H₂O, [Cu(HAmhexim)Cl₂] and [Pd(Amhexim)Cl]. Coordination is via the pyridyl nitrogen, imine nitrogen and thiolato or thione sulfur atom when coordinating as the anionic or neutral ligand, respectively. [{Cu(Amhexim)}₂C₄H₄O₄] is a binuclear complex with the two copper(II) ions bridged by the succinato group in [Cu‐(HAmhexim)Cl₂] the Cu atom is 5‐coordinate and close to a square pyramid structure and in [Ni(Amhexim)OAc] and [Pd(Amhexim)Cl] the metal atoms are planar, 4‐coordinate.