检索结果-南通市图书馆

An Electrochemical Understanding of Extraction of Silver picrate by Benzo-3m-Crown-mEthers (m= 5, 6) into 1,2-Dichloroethane and Dichloromethane

在线全文

学校读者我要写书评

暂无评论

American Journal of Analytical Chemistry 2014年第7期5卷 433-444页

作者： Yoshihiro Kudo Marina Ogihara Shoichi Katsuta Yasuyuki Takeda Graduate School of Science Chiba University Chiba Japan

Two extraction constants (Kex± and Kex) for extraction of silver picrate (Ag﹢Pic﹣) by benzo-15-crown-5 ether (B15C5) and benzo-18-crown-6 one (B18C6) into 1,2-dichloroethane (DCE) and dichloromethane (DCM) were determined at 298 K and given values of ionic strength. Here, Kex± and Kex were expressed as [AgL﹢]o[Pic﹣]o/[Ag﹢][L]o[Pic﹣] and [AgLPic]o/[Ag﹢][L]o[Pic﹣], respectively: L symbolizes B15C5 or B18C6 and the subscript “o” denotes the organic phase composed of DCE or DCM. Individual distribution constants (KD,Pic) of picrate ion, Pic﹣, into the two diluents were also determined with the determination of Kex. From comparison of these KD,Pic values with those standardized, interfacial potential differences () at extraction equilibria were evaluated. Then, using these values, relations of the experimentally-determined logKex± or logKex values with their electrochemically-standardized ones were precisely discussed. Consequently, it was indicated that logKex± should be expressed as a function of .

关键词： Individual Distribution Constants Interfacial Potential Differences Standardized Extraction Constants Silver picrate Benzo Crown Ethers Dihaloalkanes

Comparative Spectroscopic Studies on Pure, 10 and 50 mol% Glycine Mixed L-Valinium picrate Crystals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Minerals and Materials Characterization and Engineering 2014年第1期2卷 8-14页

作者： Antony A. Joseph John David I. Ebenezar Ramachandra C. Raja Government Arts College (Autonomous) Kumbakonam India St. Joseph’s College of Engineering & Technology Thanjavur India TBML College Porayar India

Nonlinear optical crystals of pure, 10 and 50 mol% glycine mixed L-valinium picrate have been grown from saturated aqueous solution by slow evaporation method at a temperature of 36℃ using a constant temperature bath of accuracy of ±0.01℃. The synthesized organic optical material has been purified by repeated recrystallization. The cell parameters were calculated using single crystal X-ray diffraction technique which confirmed the crystal system. Optical behavior was examined by UV-Vis-NIR spectrometer in the range from 190 nm to 1100 nm, which revealed the absence of absorption in the entire visible region. Functional groups and modes of vibration were identified by FT-IR spectrometer in the range between 400 cm-1 and 4000 cm-1. The 1H- and 13C NMR spectra of grown crystals were recorded using D2O as solvent on a Bruker 300 MHz (Ultrashield) TM instrument at 23℃ (300 MHz for 1H NMR and 75 MHz for 13C NMR) to confirm the molecular structure. The second harmonic generation conversion efficiency was investigated by Kurtz powder method using Nd: YAG laser as a source to explore the NLO characteristics.

关键词： Crystal Growth L-Valinium picrate FT-IR Nuclear Magnetic Resonance SHG NLO

Crystal structures of the complexes of rare earth picrates with N, N, N', N'-tetraphenyl-3, 6-dioxaoctanediamide

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 1997年第3期40卷 323-329页

作者：刘伟生柳士霞谭民裕郁开北谭干祖 Department of Chemistry Lanzhou UniversityLanzhou 730000China Chengdu Centre of Analysis and Measurement Chinese Academy of SciencesChengdu 610041China Lanzhou Institute of Chemical Physics Chinese Academy of SciencesLanzhou 730000China

The complexes of rare earth picrate with N,N,N’,N’-tetraphenyl-3,6-dioxaoctanediamide(TDD),Eu(picc(TDD)] 2CH3CN and [ Y(pic)3(TDD)],have been *** crystal structures reveal that TDD at is as n tetradentate ligand,forming a ring-like coordination structure with its oxygen atoms together with one oxygen atom of the bidentate pterate In the Eu(Ⅲ) complex,the europium ion with a larger ionic radius lies out of the ring,while in the Y(Ⅲ) complex,the yttrium ion with a smaller ionic radius enters the cavity of the *** structures of the complexes are greatly affected by the ionic radii due to participation of the picrates in coordination.

关键词： rare earth picrate open-chain crown ether ring-like coordination structure

Spectral Properties of Extracted Complexes of Metalpicrates with Crown Ethers

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 1989年第3期5卷 224-230页

作者： Zhang Xianxin and Zhou Zhixian (Department of Chemistry, Zhengzhou University, Zhengzhou)

The investigation on UV-visible spectra of species formed by extracting some metal picrates with benzo-15-crown-5(B15C5) and dibenzo-18-crown-6(DB18C6) verified that there are some interactions of picrate anion with K+, Na+ and rare earth ions in loaded organic phase. By the study of the charge transfer band and absorption spectra of picrate anion, it can be determined whether an ion pair has been formed and either a 1 : 1 contact ion pair or a 1 : 2 crown-separated ion pair involved in organic phase can be distinguished for an ion-pair extraction.

关键词： UV-visible spectra Crown ether Extraction Ion pair picrate

Crystal Structure and Spectroscopic Properties of [Ni(phen)_3]Pic_2·2CH_3CN

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2001年第2期20卷 88-92页

作者：吉保明傅玉琴孙献忠郭金波陈花婷杜晨霞 Luoyang Teacher's College Zhengzhou University

The crystal structure of the title complex having the stoichiometric formula [Ni\|(phen) 3]Pic 2·2CH 3CN (Pic=picrate anion; phen=1,10\|phenanthroline) has been determined by single-crystal X-ray diffraction. The crystal (C 52 H 34 N 14 O 14 Ni, M r=1137.63) belongs to the triclinic system, space group P1(#2) with the following crystallographic parameters: a = 14\^130(1), b=15\^256(3), c=13.673(2); α=109.11(1), β =90.92(4), γ=66.75(3)°; V=2537\^72 3, D c=1.489g/cm 3, μ(MoKα)=4.66cm -1 , F(000)=1168, Z=2, and final R=0.062 and R w=0.078 for 4917 observed reflections (I>2.00σ(I)). The analytical results of crystal structure and spectroscopic properties show that nickel(II) cation coordination environment is a distorted octahedral geometry, the Ni 2+ ion is coordinated with six nitrogen atoms~ of three phen directly, while two picrate anions and two acetonitrile molecules do not take part in coordination~.

关键词： 1.10-phenanthroline nickel(II) complex picrate crystal structure

Synthesis of New Aza-crown Ethers Containing Pyridine Ring and their Liquid Membrane Transport of Alkali Cations

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2001年第1期12卷 31-34页

作者： Bin ZHAO Feng Qin WANG Min XIA Lai Jin TIAN Department of Chemistry Qufu Normal UniversityQufu 273165 Department of Chemistry Linyi Teacher’s CollegeLinyi 276000

Five new aza-crown ethers have been prepared by the condensation of 2,6-bis[(2-formylphenyl)oxymethyl] pyridine with different diamino compounds in hot methanol, the bis-Schiff bases without isolation were reduced with NaBH4 to afford the corresponding aza-crown ethers. The liquid membrane transport or alkali cations using the five new macrocycles as the ion-carriers was also studied.

关键词： Aza-crown ether macrocycle receptor liquid membrane transport picrate

Detection of Oxidized Ferrocenes by LC-MS with Electrospray Ionization Using Picric Acid as the Counter Ion

在线全文

学校读者我要写书评

暂无评论

International Journal of Analytical Mass Spectrometry and Chromatography 2019年第1期7卷 1-8页

作者： Yutaka Okada Masako Tsuchida Department of Applied Chemistry Ritsumeikan University Kusatsu Japan

Ferrocene is an organometallic compound that readily undergoes oxidation in atmosphere under acidic conditions. However, because of its diamagnetic nature, ferrocene does not lend itself to structural analysis by nuclear magnetic resonance (NMR) spectroscopy. In this work, the oxidation of ferrocene and several of its derivatives were analyzed by liquid chromatography-mass spectrometry (LC-MS). An electrospray ionization (ESI) source was used, with picrate serving as the counter ion. This method is particularly effective for studying oxidation of ferrocenes because their reactivity toward oxygen under ambient conditions is low.

关键词： ESI LC-MS Ferrocene Oxidation picrate