Two Characteristic H-bonded O–H Stretching Bands for the Compounds Containing Ether Oxygen and Hydroxyl Oxygen

Acid cleavage of the acetoxy epoxide IIIa with aqueous perchloric acid or hydrobromic acid gave two types of products, i.e. the diol Va or the bromohydrin VIa, and the cyclic ether VIII. The latter compound arises by participation of ether oxygen of the ester group. On reaction with perchloric acid the epoxide IVa gave the diol XIIIa as a product of a normal reaction and the isomeric diol Xa as a product arising by intramolecular participation of the carbonyl oxygen of the 19-acetoxy group. Participation of the 19-ester group is confirmed by the formation of the cyclic carbonate XI when the 19-carbonate IVb is treated analogously. On reaction with hydrobromic acid, the epoxide IVa gave solely the bromohydrin XIVa as a product of the normal reaction course. Discussed is the similarity of these reactions with electrophilic additions to the related 19-acetoxy olefins I and II, the mechanism, the difference in behavior of both epoxides III and IV, the dependence of the product ratio on the nucleophility of the attacking species, and the competition between participation of an ambident neighboring group and an external nucleophile attack.

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Crystal structure of tamsulosin hydrochloride, C20H29N2O5SCl

Powder Diffraction ◽

10.1017/s0885715621000129 ◽

2021 ◽

pp. 1-7

Author(s):

Nilan V. Patel ◽

Joseph T. Golab ◽

James A. Kaduk ◽

Amy M. Gindhart ◽

Thomas N. Blanton

Keyword(s):

Crystal Structure ◽

Hydrogen Bond ◽

Hydrogen Atom ◽

Powder Diffraction ◽

Density Functional ◽

Carbon Chain ◽

Strong Hydrogen Bond ◽

Powder Diffraction File ◽

Ether Oxygen ◽

Sulfonamide Group

The crystal structure of tamsulosin hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Tamsulosin hydrochloride crystallizes in space group P21 (#4) with a = 7.62988(2), b = 9.27652(2), c = 31.84996(12) Å, β = 93.2221(2)°, V = 2250.734(7) Å3, and Z = 4. In the crystal structure, two arene rings are connected by a carbon chain oriented roughly parallel to the c-axis. The crystal structure is characterized by two slabs of tamsulosin hydrochloride molecules perpendicular to the c-axis. As expected, each of the hydrogens on the protonated nitrogen atoms makes a strong hydrogen bond to one of the chloride anions. The result is to link the cations and anions into columns along the b-axis. One hydrogen atom of each sulfonamide group also makes a hydrogen bond to a chloride anion. The other hydrogen atom of each sulfonamide group forms bifurcated hydrogen bonds to two ether oxygen atoms. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1415.

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Nanostructural Arrangements and Surface Morphology on Ureasil-Polyether Films Loaded with Dexamethasone Acetate

Nanomaterials ◽

10.3390/nano11061362 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1362

Author(s):

Joao Augusto Oshiro ◽

Angelo Lusuardi ◽

Elena M. Beamud ◽

Leila Aparecida Chiavacci ◽

M. Teresa Cuberes

Keyword(s):

Film Surface ◽

Crystalline Phases ◽

Essential Information ◽

X Ray ◽

Force Microscopy ◽

Ether Oxygen ◽

Dexamethasone Acetate ◽

Poly Ethylene ◽

The One ◽

Poly Propylene

Ureasil-Poly(ethylene oxide) (ureasil-PEO500) and ureasil-Poly(propylene oxide) (u-PPO400) films, unloaded and loaded with dexamethasone acetate (DMA), have been investigated by carrying out atomic force microscopy (AFM), ultrasonic force microscopy (UFM), contact-angle, and drug release experiments. In addition, X-ray diffraction, small angle X-ray scattering, and infrared spectroscopy have provided essential information to understand the films’ structural organization. Our results reveal that while in u-PEO500 DMA occupies sites near the ether oxygen and remains absent from the film surface, in u-PPO400 new crystalline phases are formed when DMA is loaded, which show up as ~30–100 nm in diameter rounded clusters aligned along a well-defined direction, presumably related to the one defined by the characteristic polymer ropes distinguished on the surface of the unloaded u-POP film; occasionally, larger needle-shaped DMA crystals are also observed. UFM reveals that in the unloaded u-PPO matrix the polymer ropes are made up of strands, which in turn consist of aligned ~180 nm in diameter stiffer rounded clusters possibly formed by siloxane-node aggregates; the new crystalline phases may grow in-between the strands when the drug is loaded. The results illustrate the potential of AFM-based procedures, in combination with additional physico-chemical techniques, to picture the nanostructural arrangements in polymer matrices intended for drug delivery.

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The Effect of Ether Oxygen on the Methylene Stretching Absorptions

The Journal of Organic Chemistry ◽

10.1021/jo01036a523 ◽

1963 ◽

Vol 28 (1) ◽

pp. 245-247 ◽

Cited By ~ 1

Author(s):

T. S. Wang

Keyword(s):

Ether Oxygen

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Study on the Oxidation and Spontaneous Combustion Characteristics of Jurassic Coal in North Shaanxi

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.977.124 ◽

2014 ◽

Vol 977 ◽

pp. 124-128 ◽

Cited By ~ 2

Author(s):

Jun Deng ◽

Kai Wang ◽

Xiao Wei Zhai

Keyword(s):

Functional Groups ◽

Spontaneous Combustion ◽

Combustion Process ◽

Amorphous Structure ◽

X Ray Diffraction ◽

High Oxygen Content ◽

Ether Oxygen ◽

Jurassic Coal ◽

Proximate And Ultimate Analysis ◽

Low Sulfur

Proximate and ultimate analysis, X-ray diffraction, infrared spectroscopy and thermal analysis experiments were carried out to study the spontaneous combustion oxidation based characteristic of six Jurassic coal samples from North Shaanxi in West China and three Permo-carboniferous coal samples from East China. The results showed that the characteristic of north Shaanxi Jurassic coal was low ash, low sulfur, high volatile, high oxygen content and amorphous structure. More type and quantity of reactive functional groups existed in the original Jurassic coal, such as carboxyl, methyl, methylene and ether oxygen. And the characteristic temperatures of north Shaanxi Jurassic coal sample in the oxidation and spontaneous combustion process was lower than other coal samples, due to the participation in the reaction with oxygen of the more active functional groups.

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Effect of cation size on electrochemical properties of polymer electrolyte

Iraqi Journal of Physics (IJP) ◽

10.30723/ijp.v17i42.456 ◽

2019 ◽

Vol 17 (42) ◽

pp. 76-84

Author(s):

Mohammed Kadhim Jawad

Keyword(s):

Polymer Electrolytes ◽

Ionic Conduction ◽

Weight Ratio ◽

Dielectric Behavior ◽

Gel Polymer Electrolytes ◽

Host Matrix ◽

Ether Oxygen ◽

Solution Cast ◽

Increasing Temperature ◽

Cation Size

This study investigates the ionic conduction dependence on the size of alkaline cations in gel polymer electrolytes based on double iodide can enhance by incorporating a salt having a bulky cation. Group of gel polymer electrolytes with polyethylene oxide (PEO) as a host matrix based on double salts potassium iodide (KI) and rubidium iodide (RbI) with different weight ratio prepared by using solution cast technique. The maximum value of conductivity reaches (6.03 10⁻3 at 293 K) S/cm for an electrolyte which content (KI 45%, RbI 5%) from binary salt. The ionic conductivity of for gel polymer electrolytes gradually increases by increasing temperature. The real dielectric constant results confirm that the dielectric behavior of the PEO material is a thermally activated process. FTIR results confirm that the shifting of peaks is another way to prove the interactions between PEO and binary salt ascribed to the formation of a transient cross-linking complex between the cations of the ionic liquids and the ether oxygen of the PEO.

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Study of low pressure premixed laminar dimethyl ether/oxygen/argon flames with different equivalence ratios

Fuel ◽

10.1016/j.fuel.2018.07.159 ◽

2018 ◽

Vol 234 ◽

pp. 1212-1220 ◽

Cited By ~ 2

Author(s):

Zhaoyang Chen ◽

Qianqian Li ◽

Xubo Chen ◽

Hao Chen ◽

Chunhua Zhang

Keyword(s):

Dimethyl Ether ◽

Low Pressure ◽

Ether Oxygen ◽

Premixed Laminar

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The chemistry of 2-methyltetrahydropyran-4-one: An L-Selectride reaction that gives predominantly the equatorial alcohol

Canadian Journal of Chemistry ◽

10.1139/v78-131 ◽

1978 ◽

Vol 56 (6) ◽

pp. 789-793 ◽

Cited By ~ 12

Author(s):

Donald C. Wigfield ◽

Steve Feiner

Keyword(s):

Proton Nmr ◽

Reducing Agents ◽

Cyclic Ether ◽

Nmr Analysis ◽

Ether Oxygen

The stereoisomers of 2-methyltetrahydropyran-4-ol have been separated and identified by carbon-13 and proton nmr analysis of the trideuteriomethyl-2,6,6-trideuterio analogue. Stereoisomeric product ratios of reduction of 2-methyltetrahydropyran-4-one (1) by NaBH4, KBH4, L-Selectride, K-Selectride, and LiBH(nBu)3 have been determined and compared with reductions of 3-methylcyclohexanone. Product ratios in the reduction of the two substrates by the borohydride reducing agents are similar but are quite different in the reduction by the Selectride reducing agents, 1 being reduced by Selectride to give 73% equatorialalcohol. Two possible mechanisms of reduction of 1 are proposed, involving intramolecular assistance by the cyclic ether oxygen.

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