🇺🇦 nmr_spectroscopy / organic chemistry ⌬
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https://linktr.ee/nmr_spectroscopy 🧲 Small molecules NMR 📚Theory and practice 🟢only useful information in the feed 🔴no scientific trash #nmr #nmrchat #chemistry
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доля реакций к просмотрам- 1 авг.How Much Sample Do You Need for NMR? A Practical Guide From standard 1D proton spectra to low-concentration 2D experiments: sample requirements for optimal signal-to-noise. 👉 full post on my Substack! 📱Telegram | 📱Instagram | 📱Twitter | 📱LinkedIn | ☕️BuyMeACoffee | Substack!1,93%
- 10 июл.Negative chemical shifts in ¹³C NMR? Yes, they exist! 🧲📉 Take a look at picture, showing the spectrum for diiodomethane CH₂I₂. Normally, bonding a carbon to highly electronegative halogens strips away electron density, deshielding the nucleus and pushing the signal downfield. But iodine plays by a completely different set of rules! As you can see, the ¹³C signal sits way upfield at a staggering -66.6 ppm. Why does this happen? It’s all thanks to the Heavy Atom Effect, specifically, the HALA (Heavy Atom on Light Atom effect). Because iodine is so massive, relativistic effects—primarily spin-orbit coupling—kick in. This induces a massive shielding environment at the directly attached carbon nucleus, overpowering the standard inductive effect. Fun fact: This shielding is highly localized! Notice how the ¹H shift for the CH₂ group stays perfectly normal at 3.87 ppm. The spin-orbit coupling diminishes rapidly with distance, leaving the protons largely unaffected. Have you ever worked with heavily iodinated compounds like iodoform CHI₃ or carbon tetraiodide CI₄? The shifts go even further into the negative! Drop your favorite NMR anomalies in the comments on my Substack 👇 #iodine #heavyatomeffect 📱Telegram | 📱Instagram | 📱Twitter | 📱LinkedIn | ☕️BuyMeACoffee | Substack!1,58%
- 15 июл. 2025 г.🍋 ¹H NMR of Lemon Juice (in D₂O/H₂O 10:90, 600 MHz) Freshly squeezed science! This proton NMR spectrum of lemon juice reveals a rich mixture of natural metabolites. The intense multiplets around 2.6–2.8 ppm are from citric acid, the dominant organic acid in lemon. The region between 3.0–5.3 ppm is packed with signals from sugars like glucose and fructose. You can also spot additional small molecules — amino acids, other organic acids, and possibly traces of aroma compounds — especially in the aliphatic region (0.5–2.5 ppm). Zoom-ins help uncover the fine structure of these crowded regions — a great example of the complexity of natural mixtures captured by NMR. #Lemon #Metabolomics #NaturalProducts 📱Tel | 📱Ins | 📱Tw | 📱Ln | ☕️BMC1,46%
- 30 мая 2024 г.Did you know about this easy way to identify exchangeable protons (OH, NH, SH etc.) in your ¹H NMR? Details in the picture 😉 #nmr #tricks Telegram | Instagram | Twitter | LinkedIn1,35%
- 6 авг.The hidden order behind a complex multiplet 🧩 At first glance, this ¹⁹F NMR signal might look like a chaotic forest of peaks, but it’s actually a beautiful demonstration of a higher-order XX'AA'MM'NN'R spin system. Why does a simple molecule produce such a complicated pattern? It all comes down to the crucial difference between chemical and magnetic equivalence. Thanks to the molecule's plane of symmetry, the two fluorine atoms (and their neighboring protons) are chemically equivalent. However, because they are locked in a rigid cyclic structure, each fluorine interacts (couples) differently with the other protons across the ring depending on their spatial distance and geometry. This magnetic non-equivalence, combined with the diastereotopic CH2 protons in the ring, turns what would be a simple signal into this intricate, perfectly calculable pattern. As you can see, the experimental spectrum matches the calculated one flawlessly! Find this and other building blocks at enaminestore.com #NMR #FluorineNMR #spinsystem 📱Telegram | 📱Instagram | 📱Twitter | 📱LinkedIn | ☕️BuyMeACoffee | Substack!1,24%
- 3 янв. 2025 г.без подписи1,17%
- 26 июл.❓❓ The correct answer is:1,16%
- 13 маяMessy Boronic Acid Spectrum? Stop! 🛑 Just Add Water 💧 If your ¹H NMR of a boronic acid in DMSO-d6 looks like a mixture of 5 different products, don't panic. You’re likely seeing the formation of boroxines (cyclic trimers) and oligomers. In dry DMSO, boronic acids love to dehydrate and aggregate. Since the exchange is slow, you get a "forest" of overlapping signals that make integration impossible. The NMR Trick: 💉 Add 20–50 μL of H₂O (or D₂O) directly to your tube. 🔄 Shake well. ✨ Watch the dramatic changes The water hydrolyzes the B-O-B bonds, forcing the equilibrium back to the monomeric form. As shown in the picture, you go from a complex mess (bottom) to an ideal, sharp spectrum (top). Follow for more tips and tricks! #NMR #OrganicChemistry #boron #Spectroscopy #nmrchat 📱Telegram | 📱Instagram | 📱Twitter | 📱LinkedIn | ☕️BuyMeACoffee | Substack!1,15%
- 24 июл.In today’s #NMRMultiplet we’re going to consider this complex 1H NMR signal from a norbornane derivative (centered at 2.23 ppm, labeled (tdd). 🔍 Feature Highlights: 1️⃣ Distinct W-Coupling (4J): Highlighted with the red curved line in the picture is a clear 4J(H,H) W-coupling (approximately 3.5 Hz) to a bridge syn-proton. The unique rigid skeleton provides the ideal geometry for this strong long-range “W” interaction. 2️⃣ Negligible Bridgehead Coupling (3J): Notice that there is no 3J coupling to the adjacent bridgehead proton. This is a classic Karplus relationship in action: the dihedral angle between this target proton and the bridgehead H is approximately 90°, predicting a vicinal constant near zero. 3️⃣ Decoding the rest: The other three couplings in our splitting tree are: 14.67 Hz, 14.67 Hz, and 11.13 Hz. They come from vicinal 3J(H,F) interactions and a geminal 2J(H,H) pairing. #coupling #norbornane 📱Telegram | 📱Instagram | 📱Twitter | 📱LinkedIn | ☕️BuyMeACoffee | Substack!1,08%
- 5 февр.Mastering HSQC: Say goodbye to t1 noise! 🧲✨ Ever had a beautiful HSQC ruined by those vertical noise streaks? t1 noise is a common headache, especially when dealing with high-intensity signals or spectrometer instability. Here is a 2-step trick in Mnova to clean up your spectra in seconds. 💡 Tip: Always ensure your phasing and baseline are solid before applying the noise reduction for the best results. #HSQC #processing 📱Telegram | 📱Instagram | 📱Twitter | 📱LinkedIn | ☕️BuyMeACoffee0,89%
- 18 июл.It’s #NMRweekend time! 🧲🧩 Can you identify the correct structure based on the 1D NOESY spectrum? (Honestly, the ¹H NMR alone is enough to crack this one 😉). Take part in the poll below 👇. I’ll post the full explanation in a few days! UPD ✅ The correct answer is Structure B! Why not A? The aliphatic splitting pattern simply doesn't fit. In Structure A, the methyl group is adjacent to a CH proton, meaning it would appear as a doublet. Our spectrum clearly shows a 3H singlet at 1.45 ppm. Why not C? To choose between B and C, we look at the 1D NOESY experiment. Irradiating the methyl group reveals a clear nOe correlation to the meta-coupled aromatic doublet (J = 2.5 Hz). If Structure C were correct, the proton closest to the methyl group would have an adjacent ortho neighbor, and we would see an nOe to an ortho-coupled doublet instead! All evidence points perfectly to Structure B. #nmr #nmrchat #chemistry #quiz 📱Telegram | 📱Instagram | 📱Twitter | 📱LinkedIn | ☕️BuyMeACoffee | Substack!0,88%
- 9 янв.Triphosgene (bis(trichloromethyl) carbonate) is a fascinating reagent that looks like a calm, crystalline solid 💎 but acts like a chemical powerhouse. Here are some chemistry facts and usage notes: 🧪 The «Wolf in Sheep’s Clothing» Triphosgene is primarily used as a solid substitute for phosgene gas. Phosgene is notoriously difficult to handle due to its high toxicity and gaseous state; triphosgene offers a way to «store» that reactivity in a stable, crystalline form that can be weighed out on a balance. ⚗️ Key Chemical Facts • The 3-for-1 Deal: Stoichiometrically, one mole of triphosgene is equivalent to three moles of phosgene. This makes it incredibly efficient for large-scale synthesis. • In-Situ Generation: It doesn’t usually react as a whole molecule. Instead, it is typically «cracked» in the presence of a catalyst (like pyridine or a nucleophile) to generate phosgene in situ, right when the reaction needs it. • Stability vs. Risk: While it is safer than the gas, it is still highly moisture-sensitive. In the presence of water (even humidity), it slowly hydrolyzes to release CO₂ and HCl—and potentially trace amounts of phosgene gas. Always open the bottle in a fume hood! 🏗️ Common Applications • Carbonylation: It is the «go-to» for creating carbonates and ureas. • Chlorination: Used to convert alcohols into alkyl chlorides or carboxylic acids into acid chlorides (often with better yields and milder conditions than SOCl₂ or (COCl)₂). • Isocyanate Synthesis: Crucial for the production of polyurethanes and various pharmaceutical intermediates. • Cyclization: Frequently used in medicinal chemistry to bridge two functional groups (like an amine and an alcohol) into a ring structure. #chemistry #spectroscopy #synthesis 📱Telegram | 📱Instagram | 📱Twitter | 📱LinkedIn | ☕️BuyMeACoffee0,86%