Photovoltaic and electrocatalytic properties of novel ball-type phthalocyanines bridged with four dicumarol

The new ball-type metallo bisphthalocyanines (Co(2)Pc(2) and Zn(2)Pc(2)) were synthesized from the corresponding [4,4'-bis(dicoumaroylphthalonitrile)] which can be obtained from the reaction of 3,3'-methylenebis(4-hydroxy-2H-chromen-2-one) and 4-nitrophthalonitrile. The structures of the newly synthesized compounds have been confirmed and characterized by elemental analysis, UV/Vis, IR and (1)H NMR spectroscopies and MALDI-TOF mass spectrometry. Solar cells of the configuration ITO/Co(2)Pc(2)/C60/Al and ITO/Zn(2)Pc(2)/C60/Al were fabricated. The effect of the thickness of the active Pc layer--the thickness of the Pc layer was varied from 15 to 80 nm--on solar cells parameters has been investigated. A nearly thickness independent open circuit voltage was observed in both structures. The maximum photovoltaic conversion efficiency, short circuit current and fill factor were observed in ITO/Zn(2)Pc(2)/C60/Al cell with 80 nm Pc layer to be 0.255%, 1 mA cm(-2) and 0.38, respectively. The redox properties of the ball-type complexes were investigated by cyclic voltammetry, controlled-potential coulometry and in situ spectroelectrochemistry in DMSO-TBAP. The electrochemical measurements showed that the complexes form ring-based and/or metal-based mixed-valence species, due to the remarkable intramolecular interactions between the two metal phthalocyanine units. The Vulcan XC-72(VC)/Nafion(Nf)/Co(2)Pc(2) modified glassy carbon electrode showed much higher catalytic performance towards oxygen reduction, compared to the VC/Nf/Zn(2)Pc(2) modified one. It was found that the VC/Nf/Co(2)Pc(2) catalyst is nearly insensitive to the presence of methanol. In the presence of 1 M methanol in the electrolyte, the catalytic performance of the Co(2)Pc(2)-based catalyst in oxygen reduction was much better than that of the Pt-based one. Thus, it was shown that the VC/Nf/Co(2)Pc(2) catalyst can be a good alternative to VC/Nf/Pt as a cathode catalyst in direct methanol fuel cells.     

Synthesis and spectral studies of macrocyclic Pb(II), Zn(II), Cd(II) and La(III) complexes by template reaction of 1,2-bis(2-formylphenyl)ethane with metal nitrate and various diamine

Eight new macrocyclic complexes were synthesized by template reaction of 1,4-bis(3-aminopropoxy)butane or (±)-trans-1,2-diaminocyclohexane with metal nitrate and 1,2-bis(2-formylphenyl)ethane and their structures were proposed on the basis of elemental analysis, FT-IR, UV-Vis, molar conductivity measurements, ¹H NMR and mass spectra. The metals to ligand molar ratios of the complexes were found to be 1: 1. The complexes are 1: 2 electrolytes for Cd(II), Pb(II) and Zn(II) complexes and 1: 3 electrolytes for La(III) as shown by their molar conductivities (Λ_m) in DMSO at 10⁻³ mol L⁻¹. Due to the existence of free ions in these complexes, such complexes are electrically conductive. The configurations of Cd(II) and Zn(II) complexes were proposed to probably tetrahedral, La(III) complexes are octahedral and Pb(II) complexes are octahedral geometry in the L¹ complex and tetrahedral geometry in the L² complex.     

Piano‐stool Ru (II) arene complexes that contain ethylenediamine and application in alpha‐alkylation reaction of ketones with alcohols

A series of piano‐stool Ru (II) complexes ( Ru _1–7 ) bearing ethylenediamine with aryl and aliphatic groups were prepared and fully characterized by ¹H, ¹³C, ¹⁹F and ³¹P NMR spectroscopy, FT‐IR and elemental analysis. The crystal structures of Ru _2–4 and Ru ₇ were determined by X‐ray crystallography. They were successfully applied to the alpha(α)‐alkylation of aliphatic and aromatic ketones with alcohols via the borrowing hydrogen strategy in mild reaction conditions within a short time. The catalytic system has a broad substrate scope, which allows the synthesis of alpha alkylated ketones with excellent yields. The electronic and steric effects of complexes on catalytic activity were analysed. The influence of the carbon chain length of the ligand on the alpha‐alkylation reaction of ketones was also investigated. The catalytic cycle was also examined by ¹H‐NMR spectroscopy in d₈‐toluene.     

Measurement of Differential Cross Sections for Coherent Scattering of 59.5 Kev γ Rays in the Atomic Range 26≤Z≤82

Differential cross sections for coherent scattering of 59.5 keV gamma rays at 115° were measured for 12 elements in atomic range 26≤7≤82. Experimental results were compared with theoretical values.     

Bio-inspired oxidative phenolic coupling: Total synthesis of the diarylether heptanoid (±)-pterocarine

The diaryletherheptanoid natural product, pterocarine, is expeditiously synthesized using a bioinspired intramolecular oxidative phenolic coupling of acerogenin G. The cyclization precursor is prepared from a simple cinnamic acid derivative in three high yielding synthetic operations. The key oxidative coupling is inspired by biosynthetic hypotheses; however, the oxidative coupling proceeds with concomitant hydroxylation of the diphenyl ether motif.     

An HPTLC method for the determination of oleandrin in Nerium plant extracts and its application to forensic toxicology

JPC – Journal of Planar Chromatography – Modern TLC - The study reported in this paper was aimed to develop an accurate, specific, and precise high-performance thin-layer chromatography...     

A novel urea conductometric biosensor based on zeolite immobilized urease

A new approach was developed for urea determination where a thin film of silicalite and zeolite Beta deposited onto gold electrodes of a conductometric biosensor was used to immobilize the enzyme. Biosensor responses, operational and storage stabilities were compared with results obtained from the standard membrane methods for the same measurements. For this purpose, different surface modification techniques, which are simply named as Zeolite Membrane Transducers (ZMTs) and Zeolite Coated Transducers (ZCTs) were compared with Standard Membrane Transducers (SMTs). Silicalite and zeolite Beta with Si/Al ratios 40, 50 and 60 were used to modify the conductometric electrodes and to study the biosensor responses as a function of changing zeolitic parameters. During the measurements using ZCT electrodes, there was no need for any cross-linker to immobilize urease, which allowed the direct evaluation of the effect of changing Si/Al ratio for the same type of zeolite on the biosensor responses for the first time. It was seen that silicalite and zeolite Beta added electrodes in all cases lead to increased responses with respect to SMTs. The responses obtained from ZCTs were always higher than ZMTs as well. The responses obtained from zeolite Beta modified ZMTs and ZCTs increased as a function of increasing Si/Al ratio, which might be due to the increased hydrophobicity and/or the acid strength of the medium.     

Examination of Polystyrene by Inverse GC: Part 1. Below Glass Transition Temperature

The surface properties of polystyrene were investigated by inverse gas chromatography at infinite dilution region. The standard enthalpy (??H ⁰), entropy (??S ⁰) and free energy (??G ⁰) of adsorption were calculated for the adsorption of n-alkanes (n-hexane, n-heptane, n-octane, n-nonane, n-decane) and some polar probes (acetone, ethyl acetate, DCM, chloroform, THF) on polystyrene. Additionally, the dispersive (London) component of the surface free energy (?? _S ^d ),  surface Lewis acidity (K _A ) and Lewis basicity (K _D ) of polystyrene surface were determined. The values obtained for K _A and K _D by three different methods demonstrate that polystyrene surface has a basic nature.     

The Hopf Algebra Structure of GL(1, Hq) and the Isomorphism between SPq(1)and SUq(2)

In this Letter, we introduce the Hopf algebra structure of the quantum quaternionic group GL(1, H₁) and discuss the isomorphism between the quantum symplectic group SP_q(1) and the quantum unitary group SU_q(2).