The synthesis and characterization of a new (<Emphasis Type="Italic">E,E</Emphasis>)-dioxime containing 13-membered dithiadiazamacrocyclic moieties and its mononuclear complexes

A new (E,E)-dioxime, (6Z,7Z)-15,16-dihydro-14H-dibenzo[b,h][1,10,4, 7]dithiadiazacyclotride-cine-6,7(5H,8H)-dionedioxime (H ₂ L) has been synthesized by reacting cyanogen-di-N-oxide (2) with 2,2′-[propane-1,3-diylbis(thio)]dianiline (1). Mononuclear complexes (4) and (5) of this ligand have been synthesized by reacting the vic-dioxime (H₂L) with NiCl₂ · 6H₂O and CoCl₂ · 6H₂O, respectively. The BF ₂ ⁺ capped Ni(II) and Co(III) complexes (6) and (7) of the dioxime have been synthesized from (4) and (5). The new compounds were characterized by a combination of elemental analysis, ¹H- and ¹³C-n.m.r, i.r. and m.s. spectral data.     

Synthesis,characterization and catalytic activity of peripherally tetra‐substituted Co(II) phthalocyanines for cyclohexene oxidation

New 3,3‐diphenylpropoxyphthalonitrile (5) was obtained from 3,3‐diphenylpropanol (3) and 4‐nitrophthalonitrile (4) with K₂CO₃ in DMF at 50 °C. The novel cobalt(II) phthalocyanine complexes, tetrakis‐[2‐(1,4‐dioxa‐8‐azaspiro[4.5]dec‐8‐yl)ethoxy] phthalocyaninato cobalt(II) (2) and tetrakis‐(3,3‐diphenylpropoxy)phthalocyaninato cobalt(II) (6) were prepared by the reaction of the phthalonitrile derivatives 1 and 5 with CoCl₂ by microwave irradiation in 2‐(dimethylamino)ethanol for at 175 °C, 350 W for 7 and 10 min, respectively. These new cobalt(II)phthalocyanine complexes were characterized by spectroscopic methods (IR, UV–visible and mass spectroscopy) as well as elemental analysis. Complexes 2 and 6 are employed as catalyst for the oxidation of cyclohexene using tert‐butyl hydroperoxide (TBHP), m‐chloroperoxybenzoic acid (m‐CPBA), aerobic oxygen and hydrogen peroxide (H₂O₂) as oxidant. It is observed that both complexes can selectively oxidize cyclohexene to give 2‐cyclohexene‐1‐ol as major product, and 2‐cyclohexen‐1‐one and cyclohexene oxide as minor products. TBHP was found to be the best oxidant since minimal destruction of the catalyst, higher selectivity and conversion were observed in the products. Copyright © 2012 John Wiley & Sons, Ltd.     

Chemical modification of silica gel with synthesized Schiff base hydrazone derivative and application for preconcentration and separation of U(VI) ions from aqueous solutions

Schiff base hydrazone derivative (HL) sorbent was synthesized according to the literature to be used in the adsorption and preconcentration of U(VI) ions from aqueous solution and it was exposed to immobilization, and new solid support material was obtained. For this purpose, Schiff base hydrazone derivative (HL) was chemically bonded to silica gel surface immobilized 3-aminopropyl trimethoxysilane, then analyzed by Fourier transform infrared, Brunauer–Emmett–Teller, scanning electron microscopy and elemental analysis. The influence of the solution pH, amount of sorbent, contact time, temperature, foreign ion effect and initial U(VI) concentration was investigated. The maximum U(VI) uptake capacity was found to be 8.46 mg/g.     

Application of gold-labeled antibody biosensor in simultaneous determination of total aflatoxins using artificial neural network

Preparation of antibody-coated gold nanoparticles (GNPs) specific to aflatoxins B1, B2, G1 and G2 and its use in developing aflatoxins diagnostic method were presented in this paper. The formation of gold-labeled antibodies was accomplished at optimal condition. Due to severe overlapping between the emission profiles for the aflatoxins, they cannot be determined by direct inspection of data. The strategy used in this study, constituted by artificial neural network (ANN), was easy to implement and to originate reliable results. ANN can be successfully applied to spectrofluorimetric spectra matrices to simultaneous determination of total aflatoxins. Quantitative results obtained using ANN method for aflatoxins in pistachio nuts samples were compared to those obtained using the HPLC method. Obtained results using these two methods did not show significant differences.     

Asymmetrically tetra-substituted phthalocyanine derivatives: synthesis,photophysical and photochemical properties

Transition Metal Chemistry - The syntheses of highly soluble asymmetrically substituted metal free and zinc phthalocyanine derivatives bearing three 4-(4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenoxy) and...     

Synthesis, characterization and aggregation behaviour of novel peripherally tetra-substituted octacationic water soluble metal-free and metallophthalocyanines

In this study, a new phthalonitrile derivative 3 bearing 1,3-bis[3(dimethylamino)phenoxy]propan-2-ol 1, metal-free phthalocyanine (Pc) 4, metallophthalocyanines (MPcs) 5–7 and their quaternized derivatives 4a–7a were synthesized. Metal-free Pc 4 was prepared by cyclotetramerization of phthalonitrile derivate 3 and MPcs 5–7 were synthesized by heating 3 with NiCl₂, CoCl₂ and CuCl₂ in n-pentanol in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, respectively. Quaternization of the dimethylamino functionality produced quaternized octacationic water soluble metal-free, Ni, Co and Cu Pcs which were soluble in water, DMF, DMSO. The aggregation behaviour of these compounds were investigated in different concentrations of chloroform for metal-free, Ni, Co and Cu Pcs. The effect of solvents on absorption spectra were studied in various organic solvents. The novel compounds were characterized using IR, ¹H-, ¹³C NMR, UV–vis and MS spectral data.     

Microwave-assisted synthesis and characterization of a new soluble metal-free and metallophthalocyanines peripherally fused to four 18-membered tetrathiadiaza macrocycles

Preparation of some novel symmetrically tetrasubstituted metal-free phthalocyanine (6) and metallophthalocyanines (7-10) containing four 18-membered tetrathiadiaza macrocycles moieties on peripheral positions has been achieved by cyclotetramerization reaction of phthalonitrile derivative (5) in a multi-step reaction sequence. Metal-free phthalocyanine (6) was synthesized by microwave irradiation of 13,24-bis[(4-methylphenyl)sulfonyl]-6,7,14,15,23,24-hexahydro-13H,22H-tribenzo[b,h,n][1,4,10,13,7,16]tetrathiadiazacyclo-octadecine-18,19-dicarbonitrile (5) in 2-(dimethylamino)ethanol. The metallophthalocyanines (7-10) were prepared by the reaction of the phthalonitrile compound (5) with NiCl₂, Zn(CH₃COO)₂, CoCl₂, CuCl₂ salts, respectively, by microwave irradiation in 2-(dimethylamino)ethanol for at 175 °C, 350 W. The new compounds were characterized by IR, ¹H NMR, ¹³C NMR, UV-Vis, elemental analysis and MS spectra data.     

Complexation of metal ions with the novel azathia crown ethers carrying anthracene pendant in acetonitrile–dichloromethane

A series of crown ethers carrying an anthracene group with nitrogen–sulfur donor atom, which differ in having three, four and five sulfur atoms in the macrocycle was designed and synthesized by the reaction of the corresponding macrocyclic compound and 9-chloromethyl-anthracene. The influence of metal cations such as Al³⁺, Zn²⁺, Fe²⁺, Fe³⁺, Co²⁺, Ni²⁺, Mn²⁺, Cu²⁺, Cd²⁺, Hg²⁺ and Pb²⁺ on the spectroscopic properties of the ligands was investigated in acetonitrile–dichloromethane (1:1) by means of absorption and emission spectrometry. Absorption spectra show isosbestic points in the spectrophotometric titration of Al³⁺, Zn²⁺, Fe²⁺, Fe³⁺, Cu²⁺, Hg²⁺ and Pb²⁺ the results of which disclosed the complexation compositions and complex stability constants of the novel ligands with these cations. The monoazapentathia crown ether showed sensitivity for Al³⁺ with linear range and detection limit of 2.6 × 10⁻⁶ M–2.6 × 10⁻⁵ M and 8.1 × 10⁻⁷ M, respectively.     

Synthesis and characterization of a new soluble metal-free and metallophthalocyanines bearing biphenyl-4-yl methoxy groups

The synthesis and characterization of peripherally tetra-biphenyl-4-yl-methoxy substituted metal-free (4), Ni(II) (5), Cu(II) (6), Zn(II) (7), Co(II) (8) and Pb(II) (9) phthalocyanine derivatives are reported. These new phthalocyanine derivatives show the enhanced solubility in organic solvents and they have been characterized by a combination of IR, ¹H NMR, ¹³C NMR, UV–vis, mass spectral data, elemental analysis and thermal analysis methods (TG/DTA). The photophysical (fluorescence quantum yield and lifetime) and photochemical (singlet oxygen generation and photodegradation quantum yield) properties of tetra-biphenyl-4-yl-methoxy substituted zinc (II) phthalocyanine derivative (7) are also investigated. The fluorescence of this phthalocyanine derivative (7) is effectively quenched by addition of 1,4-benzoquinone (BQ).