Spectroelectrochemistry of poly(ethylenedithiathiophene)--the sulfur analogue of poly(ethylenedioxythiophene)

Poly(3,4-ethylenedithiathiophene) (PEDTT) is a polythiophene-like conjugated polymer in which each thiophene ring is functionalized with an ethylenedithia bridge. As such, PEDTT is the sulfur analogue of the well-known poly(3,4-ethylenedioxythiophene) (PEDOT). Substituent effects, namely the presence of sulfur atoms in PEDTT replacing the oxygen atoms of PEDOT, do not provide a simple explanation for the different electronic properties of the two polymers in the neutral state. This paper reports the spectroscopic properties of PEDTT, studied by in situ techniques such as IR-, Vis-, and electron spin resonance (ESR) spectroelectrochemistry. The differences observed upon electrochemical oxidation of PEDTT and PEDOT (e.g., the different infrared active vibrational band patterns in IR spectroelectrochemistry as well as the different nature of the charged states) are even more marked than those observed in the neutral state. These results, with AM1 calculations, indicate conformational effects as a possible explanation for the different electronic and spectroscopic properties of PEDTT and PEDOT.     

Polynomial Basis Multiplication over GF(2 m )

In this paper, we describe, analyze and compare various multipliers. Particularly, we investigate the standard modular multiplication, the Montgomery multiplication, and the matrix–vector multiplication techniques.     

Determination of Naphthazarin Derivatives in 16 Alkanna Species by RP-LC Using UV and MS for Detection

As part of our ongoing studies, a new and validated method for analysis of isohexenyl-naphthazarines in Turkish Alkanna species was developed. By using reversed phase material (Synergi MAX RP) it was possible to determine four known isohexenylnaphthazarin-derivatives, namely alkannin, acetylalkannin, deoxyalkannin, and β,β-dimethylacrylalkannin within 25 min in n-hexane extracts of the roots. The quantification of these compounds in 16 Anatolian Alkanna species is described for the first time. In order to assure peak identity LC-MS experiments were performed. Quantitative results revealed that the most dominant compound in the extracts was β,β-dimethylacrylalkannin.     

Influence of the solvent on the crystal structure of PCBM and the efficiency of MDMO-PPV:PCBM ''plastic'' solar cells

Two crystal structures of PCBM, obtained from different crystallisation solvents, are presented; a proposed link with solvent dependence of the efficiency of MDMO-PPV:PCBM solar cells is described.     

Copper(II)–nickel(II) complexes of novel 1,9-dioxa-3,6-dithiacyclotridecane-10,12-dione and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione ligands

1,9-Dioxa-3,6-dithiacyclotridecane-10,12-dione (L¹), and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione, (L²), two novel ligands, and their mono- and di-nuclear copper(II) and/or nickel(II) complexes have been prepared and characterized by elemental analyses, ¹H- and ¹³C-n.m.r., i.r., magnetic moments and mass spectral studies. Elemental analyses, stochiometric and spectroscopic data on the complexes indicate that the metal ions are coordinated to the nitrogen, oxygen and sulphur atoms and the data support the proposed structure for the diones and their mono–dinuclear copper(II) complexes. Moreover, copper(II) complexes of the dione ligands have a 1:1 metal:ligand ratio.     

Studies toward the synthesis of oximidines I and II

The synthesis of compound 1, a precursor for the synthesis of the oximidine II core structure 2, is described. An undesired C8-C9 isomerization occurred during the intramolecular Castro-Stephens reaction leading to macrocyle 3. The thermodynamic driving force for this unexpected isomerization was established by DFT and MP2 calculations. [reaction: see text]     

4,5-Dimethylene -1,2-dioxane and derived Diels-Alder adducts

4,5-Dimethylene-1,2-dioxane (1) was prepared by zinc-induced debromination of 4,5-bis (bromomethyl)-1,2-dioxacylohexa-4-en (4) obtained from 2,3-bis (bromomethyl-1,3-butadiene (3) by reaction with singlet oxygen. Diels-Alder additions of 1 with singlet oxygen, dimethyl acetylenedicarboxylate and N-methyl-1,2,4-triazoline-3,5-dione gave adducts 2,6 and 8 respectively. 3,4-Disubtituted furans 5 and 9 were obtained from peroxides 4 and 8 by cobalt (II) tetraphenylporphyrin catalyzed rearrangement.     

半线性常微分方程混合边值奇摄动问题的一致差分格式*

本文应用分离奇性法研究半线性常微分方程混合边值奇摄动问题的一致差分格式,我们证明了所构造的I1'in型差分格式关于小参数ε的一阶一致收敛性.在本文的最后,我们给出一个数值例子,计算结果与理论分析相符合.     

A tetraphenylethene based polarity dependent turn-on fluorescence strategy for selective and sensitive detection of Hg in aqueous medium and in living cells

A turn-on fluorescent chemosensor strategy based on the change in the polarity of aggregation induced emission active tetraphenylethene is presented for the detection of Hg²⁺ in aqueous medium and in living cells. The sensing mechanism involves the formation of nonpolar fluorescent aggregates of tetraphenylethene molecules by elimination of polar moieties of TPE with Hg²⁺ interaction.     

Direct Electrochemical Capture and Release of Carbon Dioxide Using an Industrial Organic Pigment: Quinacridone

Limiting anthropogenic carbon dioxide emissions constitutes a major issue faced by scientists today. Herein we report an efficient way of controlled capture and release of carbon dioxide using nature inspired, cheap, abundant and non‐toxic, industrial pigment namely, quinacridone. An electrochemically reduced electrode consisting of a quinacridone thin film (ca. 100 nm thick)on an ITO support forms a quinacridone carbonate salt. The captured CO₂ can be released by electrochemical oxidation. The amount of captured CO₂ was quantified by FT‐IR. The uptake value for electrochemical release process was 4.61 mmol g^?1. This value is among the highest reported uptake efficiencies for electrochemical CO₂ capture. For comparison, the state‐of‐the‐art aqueous amine industrial capture process has an uptake efficiency of ca. 8 mmol g^?1.