• Title/Summary/Keyword: $H^1$-NMR spectra

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Spectrophotometric Determination of Phenothiazine Derivatives by using Picric acid as Electron Acceptor (Picric acid를 전자수용체로 한 Phenothiazine계 화합물의 정량법)

  • 옥치완;신태용
    • YAKHAK HOEJI
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    • v.31 no.5
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    • pp.322-329
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    • 1987
  • A rapid and sensitive spectrophotometric method has been developed for quantitation of some phenothiazine derivatives (PTZDS). The method depends on the formation of insoluble yellow complexes between PTZDS and picric acid (PCA) in aqueous layer. These complexes are quantitatively extracted from aqueous phase into chloroform. The binding ratio of PTZDS-PCA complexes were presumed as PTZDS-1 to PCA-1 by means of mole ratio and continuous variation methods. The complexes are stable for more than 24hours in chloroform layer at room temperature. Most of compounds associated with pharmaceutical preparation of PTZDS do not interfere with this method. However, chlorpheniramine and diphenhydramine interfere with the riaethod. The binding state of PTZDS-PCA complexes were presumed by IR and $^1$H-NMR spectra as intermolecular hydrogen bonding.

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Synthesis of Polymeric Thiazolidinediones and L-Ascorbic Acid Towards the Development of Insulin-Sensitizer

  • Lee Sun Mi;Jeon Raok
    • Archives of Pharmacal Research
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    • v.28 no.4
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    • pp.377-381
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    • 2005
  • Polymers, containing 5-(4-O-methylacryloylbenzyl)thiazolidine-2,4-dione [MABTZD]; poly (MABTZD), poly(MABTZD-co-AA) and poly(MABTZD-co-AMAA), were prepared, and identified by FT-IR, $^1H-$ and $^{13}C-NMR$ spectra. The MABTZD unit contents in poly(MABTZD-co-AA) and poly(MABZD-co-AMAA) were 11.3 and $27.7 mol\%$, respectively. The number average molecular weights of the polymers, as determined by GPC, ranged from 16,800 to 22,300, and with polydispersity indices of $1.2\sim1.4$.

Synthesis and Structure Identification of ABCH Type Calix[4]arenes: Two Step Synthesis of Asymmetrically Substituted Calix[4]arenes from Monoalkylcalix[4]arenes

  • 남계천;김종민;박영자
    • Bulletin of the Korean Chemical Society
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    • v.19 no.7
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    • pp.770-776
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    • 1998
  • Several ABCH type chiral calix[4]arenes were prepared from monoalkyl calix[4]arenes by treating with various acyl halide, followed by reacting with benzoyl chloride in pyridine. These asymmetrically substituted ABCH type calix[4]arenes are obtained as racemates mixture which are confirmed by the chiral shift reagent in 1H NMR spectra. The molecular and crystal structure of 5-nitro-26-allyloxy-25-benzoyloxy-28-isobutyryloxy-27-hydroxycalix[4]arene 8a has been determined by the X-ray diffraction method. Two independent enantiomeric molecules are crystallized in a 1: 1 racemate mixture. They are in the partial cone conformation in which the benzoyloxy phenyl group is down. There is a bifurcated intramolecular hydrogen bonding involving three functional groups in each molecule.

Analysis of Tridentate Schiff Base Ni(II) Complex (세자리 Schiff Base의 Ni(II) 착물의 분석)

  • Chae, Hee-Nam;Choi, Yong-Kook
    • Analytical Science and Technology
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    • v.11 no.5
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    • pp.332-340
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    • 1998
  • Tridentate Schiff base ligands, $SIPH_2$, $SIPCH_2$, $HNIPH_2$, and $HNIPCH_2$ were prepared by the reactions of salicylaldehyde and 2-hydroxy-1-naphthaldehyde with 2-aminophenol and 2-amino-p-cresol. Ni(II) complexes of those ligands were synthesized. The structures and properties of ligands and their complexes were studied by elemental analysis, $^1H$-NMR, IR, UV-visible spectra, and thermogravimetric analysis. The mole ratio of Schiff base to the metal of complexes was found to be 1:1. Ni(II) complexes were contemplated to be hexa-coordinated octahedral configuration containing three water molecules. The redox process of ligands and complexes in DMSO solution containing 0.1 M TBAP as supporting electrolyte was investigated by cyclic voltammetry and differential pulse voltammetry with glassy carbon electrode. The redox process of the tridentate Schiff base ligands was totally irreversible. The redox process of Ni(II) complexes were quasi-reversible and diffusion-controlled as one electron by one step process Ni(II)/Ni(I). The reduction potentials of the Ni(II) complexes shifted in the positive direction in the order [$Ni(II)(HNIP)(H_2O)_3$]>[$Ni(II)(SIP)(H_2O)_3$]>[$Ni(II)(SIPC)(H_2O)_3$]>[$Ni(II)(HNIPC)(H_2O)_3$] and their dependence on ligands were not so high. Consequently the [$Ni(II)(HNIPC)(H_2O)_3$] complex among the synthesized Ni(II) complexes was found to be most stable in the DMSO solution.

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Absorption of SO2 at High Temperatures by Ionic Liquids and the Absorption Mechanism

  • Tian, Shidong;Hou, Yucui;Wu, Weize;Ren, Shuhang;Qian, Jianguo
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2791-2796
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    • 2014
  • The capture of $SO_2$ at or close to the temperatures of real flue gas is much more attractive in application. In this work, two kinds of ionic liquids (ILs) based on lactate anion were used to absorb $SO_2$ at high temperatures from 100 to $120^{\circ}C$. The ILs show high absorption capacities of over one mol $SO_2$ per mol IL at $110^{\circ}C$. The absorption of $SO_2$ by the ILs based on lactate anion is reversible and the ILs can be reused for the capture of $SO_2$ at high temperatures with high absorption capacity and thermal stability. Furthermore, the absorption mechanism of $SO_2$ by the ILs was studied by FT-IR, $^1H$ NMR and $^{13}C$ NMR spectra. It has been found that there are strong chemical interactions between the ILs and $SO_2$. Also the absorption mechanism is different when there is water present in ILs compared to when there is not.

Spirodiclofen Analogues as Potential Lipid Biosynthesis Inhibitors: A Convenient Synthesis, Biological Evaluation, and Structure-Activity Relationship

  • Ke, Shaoyong;Sun, Tingting;Zhang, Zhigang;Zhang, Ya-Ni;Liang, Ying;Wang, Kaimei;Yang, Ziwen
    • Bulletin of the Korean Chemical Society
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    • v.31 no.8
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    • pp.2315-2321
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    • 2010
  • Twenty spirodiclofen analogues have been designed and conveniently synthesized via three steps including esterification, one-pot heterocyclization, and acylation reactions. The target molecules have been identified on the basis of analytical spectra ($^1H$ NMR, $^{13}C$ NMR and ESI-MS) data. All newly synthesized compounds have been screened for their potential insecticidal and herbicidal activity by standard method. The preliminary assays indicated that some of analogues displayed moderate to good insecticidal activity against Plutella xylostella compared with spirodiclofen, and some compounds showed obvious activity against Brassica chinensis. Structure-activity relationship (SAR) is also discussed based on the experimental data.

Effect of Composition and Synthetic Route on the Microstructure of Biodegradable Diblock Copolymer, Poly($\varepsilon$-caprolactone-co-L-lactide)-b-Poly(ethylene glycol)

  • Min, Youn-Jin;Lee, Seong-Nam;Park, Jung-Ki;Cho, Kuk-Young;Sung, Shi-Joon
    • Macromolecular Research
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    • v.16 no.3
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    • pp.231-237
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    • 2008
  • Biodegradable poly($\varepsilon$-caprolactone-co-L-lactide)-b-poly(ethylene glycol) (PCLA-b-PEG) copolymers were synthesized via solution polymerization by varying the feed composition of $\varepsilon$-caprolactone ($\varepsilon$-CL) and L-lactide (LLA) ($\varepsilon$-CL: LLA= 10:0, 7:3, 5:5, 3:7, 0: 10). The feed ratio based on weight is in accordance with the copolymer composition except for the case of $\varepsilon$-CL: LLA=3:7 (C3L7), which was verified by $^1H$-NMR. Two different approaches were used for the exceptional case, which is an extension of the reaction time or the sequential introduction of the monomer. A copolymer composition of $\varepsilon$-CL: LLA=3:7 could be obtained in either case. The chemical microstructure of PCLA-b-PEG was determined using the $^{13}C$-NMR spectra and the effect of the sequential structure on the thermal properties and crystallinity were examined. Despite the same composition ratio of the copolymer, the microstructure can differ according to the reaction conditions.

Synthesis and Determination of Optical Purity of C2-Symmetric Pyrrolidine Amides as Chiral Auxiliaries (키랄 보조제로서의 C2-대칭성 피롤리딘 아미드의 합성과 광학 순도 결정)

  • Moon, Hong-sik;Koh, Dongsoo
    • Applied Chemistry for Engineering
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    • v.9 no.6
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    • pp.914-919
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    • 1998
  • Optically pure $C_2-Symmetric$ pyrrolidine amides (8) were synthesized from readily available 1,2:5,6-di-O-isopropylidene-D-mannitol (1). Cyclization of dimesylated hexitol (4) with benzyl amine gave an inseparable mixture of $C_2-Symmetric$ pyrrolidine amine derivative (5) as a major product, concurring with its cis isomer (6) as a minor product. The pyrrolidine amines (5,6) were converted to separable pyrrolidine amides (8,9) via free amine (7). Optical purity of desired $C_2-Symmetric$ pyrrolidine amide (8a) was determined with its Mosher derivatives (13,14) by their $^1H$ and $^{19}F$ NMR spectra.

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Synthesis and Properties of Poly[oxy(arylene)oxy(tetramethyldisilylene)]s via Melt Copolymerization Reaction

  • Jung, Eun Ae;Park, Young Tae
    • Bulletin of the Korean Chemical Society
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    • v.34 no.6
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    • pp.1637-1642
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    • 2013
  • We carried out the melt copolymerization reactions of 1,2-bis(diethylamino)tetramethyldisilane with several aryldiols such as, 4,4'-biphenol, 4,4'-isopropylidenediphenol, 9H-fluoren-9,9-dimethanol, and 4,4'-(9-fluorenylidene) bis(2-phenoxyethanol) to afford poly[oxy(arylene)oxy(tetramethyldisilylene)]s containing fluorescent aromatic chromophore groups in the polymer main chain: poly[oxy(4,4'-biphenylene)oxy(tetramethyldisilylene)], poly[oxy{(4,4'-isopropylidene) diphenylene}oxy(tetramethyldisilylene)], poly[oxy(9H-fluorene-9,9-dimethylene) oxy(tetramethyldisilylene)], and poly[oxy{4,4'-(9-fluorenylidene)bis(2-phenoxyethylene)}oxy(tetramethyldisilnylene)]. These prepared materials are soluble in common organic solvents such as $CHCl_3$ and THF. The obtained polymers were characterized by several spectroscopic methods such as $^1H$, $^{13}C$, and $^{29}Si$ NMR. Further, FTIR spectra of all the polymers exhibited characteristic Si-O stretching frequencies at 1014-1087 $cm^{-1}$. These polymeric materials in THF showed strong maximum absorption peaks at 268-281 nm, strong maximum excitation peaks at 263-291 nm, and strong maximum fluorescence emission bands at 314-362 nm due to the presence of tetramethyldisilylene and several arylene chromophores in the polymer main chain. TGA thermograms indicated that most of the polymers were stable up to $200^{\circ}C$ with a weight loss of 3-16% in nitrogen.

Synthesis and Photovoltaic Properties of Conducting Polymers Based on Phenothiazine (Phenothiazine계 전도성고분자의 합성 및 유기박막태양전지로의 적용 연구)

  • Yoo, Han-Sol;Park, Yong-Sung
    • Applied Chemistry for Engineering
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    • v.24 no.1
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    • pp.93-98
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    • 2013
  • In this paper, four conducting polymers (poly[(N-butyl-phenothiazine)-sulfide] (PBPS), poly[(N-hexyl-phenothiazine)-sulfide] (PHPS), poly[(N-decyl-phenothiazine)-sulfide] (PDPS), and poly[(N-(2-ethylhexyl)-phenothiazine)-sulfide] (PEHPS)) were synthesized with a high temperature and high pressure reaction. The structures of synthesized polymers were confirmed by $^1H-NMR$ and characterized by UV-Vis, cyclic voltammetry, and GPC. From the UV-Vis absorption spectra, the ${\lambda}_{max}$ values of PBPS, PHPS, PDPS, and PEHPS were 338, 341, 340, and 334 nm, respectively and their optical band gaps were 3.11, 3.13, 3.16, and 3.05 eV, respectively. To evaluate the feasible applicability as a photovoltaic cell, the devices composed of for example, ITO/PEDOT : PSS/polymer (PBPS, PDPS) : $PC_{71}BM$ (1 : 3, w/w)/$BaF_2$/Ba/Al were fabricated using the blends of the PBPS and PDPS as a donor, and $PC_{71}BM$ as an acceptor. Then, the power conversion efficiencies (PCE) of devices were estimated as 0.076% of PBPS and 0.136% of PDPS by solar simulator.