​Continuation of the previous post. The easiest solution of this problem is salt preparation and 1H spectrum analysis in DMSO-d6 ☝🏻. Save and Share! 😉 Author of the molecule @Kleban_ihor #nmr #nuclearmagneticresonance #nmrchat #chemistry #chemie #quimica #Ukraine #Kyiv #enamine

​Magnetic anisotropy effects 📝, caused by local electrons circulation, can dramatically change some chemical shifts, especially in aromatic and antiaromatic compounds😮.
DETAILS: https://organicchemistrydata.org/hansreich/resources/nmr/?page=nmr-content%2F
#nmr #nuclearmagneticresonance #nmrCHAT #chemistry #chemie #quimica #science #Ukraine #enamine

​A simple Saturday task for our little NMR community 😉. Write your answer with explanations in the comments section 👇🏻 #nmr #nmrChat #chemistry #quimica #chemie #organichemistry #spectroscopy #Kyiv #Ukraine #Enamine

NMRbox release 2021-51. 6 VMs. 2 new A100 GPU chips. AlphaFold.

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​The answer to the previous post ☝🏻. We consider only HMBCs to COO- Carbon and not 13C of the ring, because 2Js often as small as 4Js which can be confusing.
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#nmr #nuclearmagneticresonance #chemistry #chemie #quimica #spectroscopy #Kyiv #KNU #Ukraine #enamine

​Here is one of the tricks I often use in my NMR structure elucidation practice. Inter- or intramolecular proton exchange can be a real problem for a heterocyclic aromatic compound that has plenty of exchangeable acidic protons (OH, NH, CONH, etc.)☝🏻. It often broadens almost all signals of the nearest CH groups, which makes the acquisition of high-quality 2D spectra difficult or impossible (as in the case of HMBC). Solution - try to add a little amount of trifluoroacetic acid (e.g. 50 µL)😉. Details in the picture.
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#nmr #nmrchat #nuclearmagneticresonance #chemistry #organicchemistry #chemie #quimica #Ukraine #Kyiv #enamine

​Through NMR with subscribers 🚀. If you have interesting NMR problems / questions - send them in private messages😉. #NMR #NMRchat #nuclearmagneticresonance #spectroscopy #chemistry #organicchemistry #science #quimica #chemie #enamine #Kyiv #Ukraine

​A little complicated 🤯 but useful material on the analysis of 13C satellites☝🏻. The key idea here is that 13C isotope breaks the symmetry of such molecules. Therefore, satellite analysis allows one to get additional coupling data, and, as a consequence, structural information😉.

​An example of how one problem can be solved in several ways.

​A simple NMR task for our little NMR community 😉.

​The answer to the previous post. Many of you chose NOESY. It is right too but not the most appropriate)
#nmr #nmr_task #nmrchat

​Through NMR with subscribers 🚀 (II). If you have interesting NMR problems / questions - send them in private messages😉. #nmr_problems

​24.02.2022 Russia started brutal bloody war against my country, against #Ukraine, against the whole world, against humanity and against God himself. Until the last moment, no one could believe that the crazy old bustard #putin had enough brains for this. But it happened. The 7th day of the war is already underway. Many killed children, women, old people, military and civilian people. The whole world supports Ukraine. Unprecedented sanctions were imposed against Russia and the country is confidently turning into a pariah country. Ukraine will fight till the end and win. And the country that will be born out of all this horror will be completely different - strong, beautiful, prosperous and united. In the meantime, sorry folks, now is not the time for NMR content.

Non-Uniform Sampling (NUS) is an acquisition method for NMR experiments with two or more dimensions. With NUS, only a subset of the usual linearly sampled data is
recorded (50%, 25% etc.). Reconstruction algorithms are used to get a correct spectrum from such sparse data set.
DETAILS: https://www.agilent.com/cs/library/applications/5991-2109EN.pdf
Two main approaches to use NUS for nD spectra acquisition:
reducing the experiment time (especially for 3D, 4D exps.) or increasing the resolution of the spectra in the same time. PICTURE: example of 1H-13C HSQC spectra of sugar with TD in F1 400 points and different sampling densities for reducing of acquisition time. #nmr #nmrchat #chemistry #organicchemistry #Ukraine #Enamine #standwithukraine

#NUS is a great method to increase the resolution of 2D #NMR (especially for long-time experiments) in the same time. The example - HMBC of #dexamethasone (#glucocorticoid medication). Time of each experiment - 22 min. Only part of the spectrum is shown. Signals circled in blue are the most representative. #chemistry #organichemistry #covid_19 #nuclearmagneticresonance

Even in these days of high-field #NMR, it's often happens that proton spectra show either overlap of signals or higher-order effects because of small chemical shift differences. In this cases a simple changing of solvent or addition of aromatic solvent can dramatically simplify the spectrum. The example is in the picture. #chemistry #organichemistry #nmrchat #nuclearmagneticresonance #nmr_tricks

Continuation of the previous post. ASIS for aliphatics. The key group in this case was CH2 2.04+0,93. The proton signal at 2.04 ppm became more resolved after addition of benzene, which made the problem solving more accurate. #nmr #nmrchat #nmr_tricks Author of the molecule - @EWGROUP