A neutral tetradentate ligand L1 [L1?=?3,6-bis(pyrazol-1-yl)-pyridazine] reacts with Ni(ClO4)2·6H2O and undergoes counterion exchange with PF?6 to give di- and tetranuclear complexes [Ni2(L1)2(CH3CN)4](PF6)4·4H2O (1) and [Ni4(L1)4(µ-OH)4](ClO4)4·2H2O (2), respectively. The presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as base controls the nuclearity of the complex formation. Both complexes were structurally characterized by physicochemical and spectroscopic techniques. Their crystal structures revealed that both complexes are centrosymmetric and adopt slightly distorted octahedral geometry. Complex 1 crystallizes in monoclinic space group C2/c as the Ni(II) center is octahedrally bound to L1 in a trans-isomer arrangement. Complex 2 crystallizes in tetragonal space group I41/amd with four L1 and four hydroxy bridging ligands linked to Ni(II) center in cis-isomer arrangement. Cyclic voltammograms of complexes 1 and 2 were measured under Ar and CO2. Under CO2, the quasireversible peaks of both complexes become irreversible and a current enhancement occurs under reduction.
The design and synthesis of Aviram–Ratner‐type molecular rectifiers, featuring an anilino‐substituted extended tetracyanoquinodimethane (exTCNQ) acceptor, covalently linked by the σ‐spacer bicyclo[2.2.2]octane (BCO) to a tetrathiafulvalene (TTF) donor moiety, are described. The rigid BCO spacer keeps the TTF donor and exTCNQ acceptor moieties apart, as demonstrated by X‐ray analysis. The photophysical properties of the TTF‐BCO‐exTCNQ dyads were investigated by UV/Vis and EPR spectroscopy, electrochemical studies, and theoretical calculations. Langmuir–Blodgett films were prepared and used in the fabrication and electrical studies of junction devices. One dyad showed the asymmetric current–voltage (I–V) curve characteristic for rectification, unlike control compounds containing the TTF unit but not the exTCNQ moiety or comprising the exTCNQ acceptor moiety but lacking the donor TTF part, which both gave symmetric I–V curves. The direction of the observed rectification indicated that the preferred electron current flows from the exTCNQ acceptor to the TTF donor. 相似文献
This paper deals with the effects of optical radiation on a uniformly doped three dimensional nano scale SOI MOSFET including quantum mechanical effects. The model takes into account all the major effects that determine the device characteristics in the illuminated condition. The device characteristics are obtained using self-consistent solution of 3D Poisson–Schrodinger equations using Leibman's iteration method. Calculations were carried out to examine the effect of illumination on the surface potential, current–voltage characteristics, drain to source resistance (Rds), sub threshold characteristics and transconductance (gm). The obtained characteristics are used to examine the performance of the device for its suitable use as a photodetector in opto-electronic integrated circuit (OEIC) receivers. 相似文献
Malaria is the number one infectious disease in the world today. Worldwide, over two million people die each year from malaria. This shocking reality is largely due to the emergence of drug resistant strains of Plasmodium falciparum. Artemisinin, a sesquiterpene lactone endoperoxide isolated from Artemesia annua has been shown to be a fast acting, safe and effective drug against multidrug-resistant and sensitive strains of P. falciparum. This article reports a survey of the literature dealing with artemisinin related antimalarial issues that have appeared from 1980s to the beginning of 2003. A broad range of medical and pharmaceutical disciplines is covered, including a brief introduction about discovery, phytochemical aspects, antimalarial mechanism of action, pharmacokinetics, and major drawbacks and various structural modifications made to overcome them. 相似文献
Tin sulphide (SnS) thin films were deposited on glass substrate at different substrate temperature (Ts = 325 °C, 350 °C and 375 °C) by pyrolytic decomposition using stannous chloride and thiourea as precursor solutions. Also, indium-doped SnS thin films were prepared by using InCl3 as dopant source. The dopant concentration [In/Sn] was varied from 2 at% to 6 at%. The XRD analysis revealed that the films were polycrystalline in nature having orthorhombic crystal structure with a preferred grain orientation along (1 1 1) plane. Due to In doping, the orientation of the grains in the (1 1 1) plane was found to be deteriorated. Atomic force microscopy (AFM) measurements revealed that the surface roughness of the films decreased due to indium doping. The optical properties were investigated by measuring the transmittance characteristics which were used to find the optical band gap energy, refractive index and extinction coefficient. The energy band gap value was decreased from 1.60 to 1.43 eV with increasing In concentration. The photoluminescence (PL) measurements of thin films showed strong emission band centered at 760 nm. Using Hall Effect measurements electrical resistivity, carrier concentration and Hall mobility have been determined. 相似文献
A simple and sensitive liquid chromatographic method has been developed for the determination of low molecular weight aliphatic amines after their pre-column derivatization with naphthalene-2,3-dicarboxaldehyde (NDA). Derivatization conditions, including the NDA concentration, reaction pH and reaction time have been investigated for method optimization. The chromatographic separation of five amines was performed on ABZ PLUS column using mobile phase of methanol-water (80:20, v/v) at a flow rate of 0.2 mL min−1. The detection was carried out with a 6 mm glassy carbon electrode at the applied potential of 0.7 V versus Ag/AgCl reference electrode. The detection limits were between 23.3 and 34.4 nmol L−1 of amines with a sample injection volume of 2 μL. The present method was applied for the determination of aliphatic amines in lake water. The recovery ranged 52.2-127.9%. The RSD in analytes retention time was less than 0.3% and 2.4% for intra- and inter-day analyses, respectively. The RSD in peak area was below 5.8% for both intra-day and inter-day analyses. The total analysis was completed within 20 min. 相似文献