نتایج جستجو برای: دینامیک 1h nmr

تعداد نتایج: 85931  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده علوم پایه 1391

در این پایان نامه، بررسی دینامیک ایلیدهای پایدار فسفر به عنوان محصول عمده از واکنش افزایشی 1:1:1، بین تری اتیل فسفیت یا تری فنیل فسفین با دی متیل استیلن دی کربوکسیلات در حضور یک n-h اسید قوی مطالعه می شود. این ایلیدهای پایدار به صورت مخلوطی از 2 ایزومر هندسی در اثر چرخش محدود شده حول پیوند دوگانه کربن-کربن (c=c) به وجود می آیند. پارامترهای فعال سازی این اثر در طیف های 1h nmr ایلیدهای فسفر توسط ...

Journal: :journal of the iranian chemical research 0
muhammed basheer ummathur department of chemistry, unity women’s college, manjeri, kerala-676122, india anjali krishnan department of chemistry, unity women’s college, manjeri, kerala-676122, india mathew paul ukken department of chemistry, christ college, irinjalakuda, kerala-680125, india

condensation of aromatic aldehydes with benzoyl acetone under specified conditions yieldedtwo series of polycarbonyl compounds in which the keto group is attached to olefinic linkage.spectral and analytical data revealed the formation of an unsaturated triketone from pyridine-3-carbaldehyde and unsaturated diketone from furfural, salicylaldehyde and 2-hydroxynaphthaldehyde. analytical, ir, 1h n...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده علوم 1389

همانطور که می دانیم قدمت سنتز ایلید ها به 70 سال پیش بر می گردد، قبلاً پدیده دینامیک 1h nmr حول چرخش یک یا دو پیوند صورت گرفته است ولی در سالهای اخیر برای اولین بار، بررسی دینامیک همزمان سه چرخش حول پیوندها در ایلید فسفر ویژه ای در سال 2009 گزارش شد. این کار آغازی شد برای بررسی d nmr در ایلیدها و انامینو استرهایی که بیش از یک چرخش دارند. این حقیقت ویژه باعث شد برای بررسی سینتیک مربوط به تبدیلاتی...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1995
mehran ghiaci ahmad reza massah

the 1h and natural-abundance 13c-nmr spectra of 1-thiacyclooctan-3-one (1) have been measured from 25 to -100°c. coalescence is observed in the 1h-nmr spectra of (1) at about -80°c, and attributed to ring inversion in a boat-chair conformation, which is the predominant conformation of (1). the free energy of activation (dg¹) for this process is 9.2±0.2 kcal/mol. the 13c-nmr spectra of (1) is te...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1988
mehran ghiaci

body's iterative force-field computer program has been used to calculate strain energies in cyclooctanone (i). 348 mhz 1h nmr spectra of (i) have been investigated over the temperature range of 25° to -160°c. two conformation processes affect the 1h nmr spectrum of (i). iterative force-field calculations on the conformations and conformational interconversion paths of (i) give results consisten...

2010
Augusta Caligiani Gerardo Palla Annalisa Maietti Martina Cirlini Vincenzo Brandolini

1H NMR spectra were recorded of methanolic extracts of seven soybean varieties (Glycine max.), cultivated using traditional and organic farming techniques. It was possible to identify signals belonging to the groups of amino acids, carbohydrates, organic acids and aromatic substances in the spectra. In the aromatic zone, the isoflavone signals were of particular interest: genistein, daidzein, g...

Journal: :journal of the iranian chemical research 0
muhammed basheer ummathur department of chemistry, kahm unity women’s college, manjeri, kerala-676122, india anjali krishnan department of chemistry, kahm unity women’s college, manjeri, kerala-676122, india perumpalli ummer department of chemistry, university of calicut, kerala-673635, india

the coupling of tetrazotised 1,8-diaminonaphthalene with 1,3-dicarbonyl compounds [acetylacetone,methylacetoacetate and acetoacetanilide] yielded a new series of tetradentate ligand systems. analytical, ir,1h nmr and mass spectral data indicate that the compounds exist in the intramolecularly hydrogen bondeddihydrazone form. dibasic tetradentate n2o2 coordination of these compounds in their [ml...

Journal: :Journal of agricultural and food chemistry 2016
Chukwan Techakanon Thomas M Gradziel Diane M Barrett

Peach cultivars contribute to unique product characteristics and may affect the degree of browning after high-pressure processing (HPP). Nine peach cultivars were subjected to HPP at 0, 100, and 400 MPa for 10 min. Proton nuclear magnetic resonance (1H NMR) relaxometry, light microscopy, color, polyphenol oxidase (PPO) activity, and total phenols were evaluated. The development of enzymatic bro...

Journal: :Molbank 2022

The title compound, 5-(1H-indol-3-yl)-1-methyl-3-phenyl-1,6-benzodiazocin-2(1H)-one, was synthesized for the first time by a one-step, two-component reaction between 1-methylbenzimidazole and benzoylindolyl-3-acetylene. product characterized 1H-NMR, 13C-NMR, IR spectroscopy HRMS.

Journal: :Zeitschrift fur Naturforschung. C, Journal of biosciences 2013
Abou El-Hamd H Mohamed Hosam-Eldin H Mahmoud Fathy F Abdellatif Yousif S Mohamed Ahmed A Ahmed Shinji Ohta

The aerial parts of Inula verbascifolia afforded two new guaianolide-type sesquiterpene lactones. Their structures were determined by spectroscopic methods (IR, MS, 1H NMR, 13C NMR, DEPT, 1H-1H COSY, HMQC, and HMBC).

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید