For the first time at CMR Dr. Benjamin Koeppe has synthsized a mixture of deuterated freon gases (CDF3/CDF2Cl). Liquefied freons may serve as a solvent for extra low-temperature NMR experiments in liquid state (down to 100 K).
References:
1. B. Koeppe, J. Guo, P.M. Tolstoy, G.S. Denisov, H.-H. Limbach, “Solvent and H/D Isotope Effects on the Proton Transfer Pathways in Heteroconjugated Hydrogen-Bonded Phenol-Carboxylic Acid Anions Observed by Combined UV–vis and NMR Spectroscopy”, J. Am. Chem. Soc. 2013, 135, 7553-7566. DOI: 10.1021/ja400611x.
2. J. Guo, P.M. Tolstoy, B. Koeppe, N.S. Golubev, G.S. Denisov, S.N. Smirnov, H.-H. Limbach, “Hydrogen Bond Geometries and Proton Tautomerism of Homo-Conjugated Anions of Carboxylic Acids Studied via H/D Isotope Effects on 13C NMR Chemical Shifts”, J. Phys. Chem. A 2012, 116, 11180-11188. DOI: 10.1021/jp304943h.
3. D. Ajami, P.M. Tolstoy, H. Dube, S. Odermatt, B. Koeppe, J. Guo, H.-H. Limbach, J. Rebek Jr., “Compressed Hydrogen Bonds Isolated in Encapsulation Complexes”, Angew. Chem. Int. Ed. 2011, 50, 528-531. DOI: 10.1002/anie.201002182.
4. P.M. Tolstoy, P. Schah-Mohammedi, S.N. Smirnov, N.S. Golubev, G.S. Denisov, H.-H. Limbach, „Characterization of Fluxional Hydrogen-Bonded Complexes of Acetic Acid and Acetate by NMR: Geometries and Isotope and Solvent Effects”, J. Am. Chem. Soc., 2004, 126, 5621-5634. DOI: 10.1021/ja039280j.
Archive for May 28, 2015
Solvent for extra low-temperature NMR
A. Rozentsvet has presented a lecture
On 21.05 at CMR Dr. Victor A. Rozentsvet (Institute of Ecology of the Volga River Basin, Russian Academy of Sciences, Togliatti, Russia) has presented a lecture titled “Unusual NMR spectra of branched diene polymers. Questions without answers.”
Combined acquisition of NMR and UV-vis absorption spectra
Dr. Benjamin Koeppe (Humboldt-Universität zu Berlin, Germany), who previously worked in the group of Prof. Dr. Hans-Heinrich Limbach and developed a technique for the combined acquisition of NMR and UV-vis absorption spectra (UVNMR), is installing and demonstrating the equipment at the CMR. The figure shows NMR and UV-vis spectra of 2-chloro-4-nitrophenol dissolved in chloroform, obtained simultaneously within the magnet of an NMR spectrometer..
Dr. Benjamin’s Koeppe presentation
On Monday 18.05.15 at 15:00 in the room 1093 (seminar room of X-ray diffraction center) our guest Dr. Benjamin Koeppe (HU Berlin, Germany) will give a presentation titled “Combined NMR and UV-vis studies of hydrogen bonded complexes”.
April
Total in April 1664 service applications were carried out.
All together measured:
- 1600 1H spectra
- 376 13C spectra
- 180 DEPT spectra
- 21 COSY spectra
- 4 NOESY spectra
- 36 31P spectra
- 108 19F spectra
208 applications were carried out which jointly took 1831 hours of measurements.