Solvatochromic Solvent Polarity Measurements In Analytical Chemistry: Synthesiss And Applications Of Et-30

Abstract

The E_T(30) scale of solvent polarity has been shown to be useful in examining many diverse analytical processes. It is based on the charge transfer absorption of 2,6-diphenyl-4-(2,4,6-triphenyl-N-pyridinio)phenolate (referred to as ET-30 in this paper). Unfortunately, use of the E_T(30) scale has been hindered by (a) the lack of a commercial source of the ET-30 dye and (b) the lack of an English language synthetic procedure. Here we discuss recent applications of the E_T(30) scale to analytical techniques, as well as a simplified procedure for the synthesis of ET-30.     

Separation and Analysis of o.p'-DDD and its Lipophilic Metabolite,O.P'-DDE,in Tissue,Faeces and Plasma

Abstract

An analytical procedure based on electron capture gas chromatography for the determination of o,p′-DDD, a drug used for the treatment of Cushing′s syndrome, is presented. Detection of a metabolite, identified as o,p′-DDE, is also described.     

A 2D Co(II) coordination polymer based on 1,3,5-tris(1H-imidazol-1-yl)benzene: photocatalytic properties and theoretical analysis

Abstract

A new 2D Co(II) based coordination polymer (CP), {[Co₂(tib)₂(NO₃)₃(H₂O)₂·NO₃]_n (1), has been synthesized using 1,3,5-tris(1-imidazolyl)benzene (tib) ligand. The single crystal X-ray diffraction study indicates that 1 possesses an infinite 2D layer, which is further extended into a 3D supramolecular network via O–H···O hydrogen bonding interactions. Additionally, the thermogravimetric analysis (TGA) of CP indicates its decomposition temperature was about 268?°C. The UV/Vis diffuse-reflection spectrum of 1 indicates its semiconducting nature on the basis of which the photocatalytic properties of 1 against photodecomposition of organic dyes have been studied. The possible mechanism associated with the photocatalytic activity of 1 against organic dyes is addressed using density of states (DOS) calculations.     

Some MnIII-porphyrins with de-polymerization activity toward humic acid

Four Mn^III-porphyrin complexes, chloro(tetraphenylporphinato)Mn^III(1,6-diaminohexane), bromo(tetraphenylporphinato)Mn^III(1,6-diaminohexane), azido(tetraphenylporphinato)Mn^III(1,6-diaminohexane), and thiocyanato(tetraphenylporphinato)Mn^III(1,6-diaminohexane), have been synthesized. These complexes have been characterized using UV-Vis, IR, ESI-mass spectra, elemental analyses, magnetic susceptibility measurements, and conductivity measurement. The molar conductance values of these complexes in ethanol indicate non-electrolytes. The utility of these complexes in de-polymerization of coal using humic acid as the coal model has been tested by the optical density method.     

Ligational behavior of new mononucleating NOO ethyl pyruvate Schiff base towards 3d metal(II) ions: an emphasis on antiproliferative and photocleavage property

A series of Co(II), Ni(II), Cu(II), and Zn(II) complexes of a tridentate hydrazone were prepared and characterized by various spectro‐analytical techniques and magnetic moment studies. The complexes were found to be monomeric and non‐electrolytes. The copper complex is electrochemically active in the applied potential range. The compounds synthesized in the present study have shown promising antiproliferative activity when screened using the in vitro method against two human cancer cell lines: HeLa and HepG2. The Escherichia coli DNA‐binding properties of all the compounds were investigated with UV–visible absorption spectrophotometric titrations, viscosity measurements, DNA melting experiments and gel electrophoreses measurements. The compounds were demonstrated to act as DNA intercalators with appreciable DNA‐binding constant values. Copyright © 2012 John Wiley & Sons, Ltd.     

Biological evaluation of novel selenazole‐based compounds as potential thioredoxin reductase inhibitors

Recently, thioredoxin reductase as a target for treatment of tumors has attracted the attention of scientists. 1,2‐[Bis(1,2‐benzisoselenazolone‐3(2 H)‐ketone)]ethane (ethaselen, BBSKE, PCT: CN02/00412), designed and synthesized previously, is an effective thioredoxin reductase inhibitor; presently it is in phase II clinical trials, targeting gastric cancer, lung cancer and colon cancer. To seek more novel and effective anticancer drugs, we have developed many selenazole‐based compounds. Evaluation of the thioredoxin reductase inhibitory effect and investigation of the mechanism of anticancer drugs require abundant thioredoxin reductase, but since commercial thioredoxin reductase is expensive its use is often limited. Therefore, the preparation of thioredoxin reductase is necessary. Base on the above investigation, in this work we have prepared thioredoxin reductase and evaluated selenazole‐based compounds, and found that 44 compounds have high inhibitory effect on thioredoxin reductase with IC₅₀ < 10 µ m , of which 16 compounds have IC₅₀ values below 1 µ m . This is helpful in investigating and elucidating the mechanism of this kind of compound. Copyright © 2012 John Wiley & Sons, Ltd.     

Temperature Dependence of 1H Paramagnetic Chemical Shifts in Actinide Complexes,Beyond Bleaney's Theory: The AnVIO22+–Dipicolinic Acid Complexes (An=Np,Pu) as an Example

Actinide +VI complexes ( = , and ) with dipicolinic acid derivatives were synthesized and characterized by powder XRD, SQUID magnetometry and NMR spectroscopy. In addition, and complexes were described by first principles CAS based and two-component spin-restricted DFT methods. The analysis of the ¹H paramagnetic NMR chemical shifts for all protons of the ligands according to the X-rays structures shows that the Fermi contact contribution is negligible in agreement with spin density determined by unrestricted DFT. The magnetic susceptibility tensor is determined by combining SQUID, pNMR shifts and Evans’ method. The SO-RASPT2 results fit well the experimental magnetic susceptibility and pNMR chemical shifts. The role of the counterions in the solid phase is pointed out; their presence impacts the magnetic properties of the complex. The temperature dependence of the pNMR chemical shifts has a strong contribution, contrarily to Bleaney's theory for lanthanide complexes. The fitting of the temperature dependence of the pNMR chemical shifts and SQUID magnetic susceptibility by a two-Kramers-doublet model for the complex and a non-Kramers-doublet model for the complex allows for the experimental evaluation of energy gaps and magnetic moments of the paramagnetic center.     

Bioactive materials for bone regeneration based on zinc-modified hydroxyapatite

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A calibrated model of local food system of Hawaii: What are the economic implications of the state's food goals and policies?

We develop a fully calibrated positive mathematical programming model for Hawaii's local food systems—which captures the production and the consumer sides of the market. Then we use the model to assess two proposed policies—a general excise tax (GET) exemption on locally produced foods, and an investment in agricultural infrastructure. For the GET exemption case, our results indicate an economic gain of $118 per $100 cost. On the other hand, an investment in 1,200 acres of land injected to support local production may generate an economic gain of up to $357 per $100 annual cost of the investment. However, these estimates should be considered preliminary, and thus viewed with caution. Although the model is used to capture Hawaii's local food systems, we believe that our model is generalizable and can be adopted by other economies to assess their respective food localization policies. Recommendations for Resource Managers

• Local food policies need to be based on quantitative terms instead of mere armchair speculation because often their potential outcomes may vary significantly.

• The current modeling framework demonstrates the potential of using positive mathematical programming (PMP) in capturing the intricacies of local food systems. However, this exploratory exercise should be viewed as preliminary in nature and the ensuing results were taken with caution because many important factors such as labor availability may have been left out.

• Thus, further model refinements are necessary to better capture the complexities of local food systems such as farm heterogeneity, availability of farm labor, water availability, and interisland transportation of farm products in the case of Hawaii.