Prospects and limits of NMR Click to edit Master title style spectroscopy Riina Aav Associate Professor Department of Chemistry Faculty of Science Tallinn University of Technology Historic insight Otto Stern The Nobel Prize in Physics 1943 (1944) was awarded to Otto Stern "for his contribution to the development of the molecular ray method and his discovery of the magnetic moment of the proton“. Isidor Isaac Rabi The Nobel Prize in Physics 1944 was awarded to Isidor Isaac Rabi "for his resonance method for recording the magnetic properties of atomic nuclei". Felix Bloch The Nobel Prize in Physics 1952 was awarded jointly to Felix Bloch and Edward Mills Purcell "for their development of new methods for nuclear magnetic precision measurements and discoveries in connection therewith" Edward Mills Purcell Aav, POKE Workshop, 12.12.2013 2 Historic insight Richard R. Ernst The Nobel Prize in Chemistry 1991 was awarded to Richard R. Ernst "for his contributions to the development of the methodology of high resolution nuclear magnetic resonance (NMR) spectroscopy". Kurt Wüthrich, John B. Fenn, Koichi Tanaka The Nobel Prize in Chemistry 2002 was awarded "for the development of methods for identification and structure analyses of biological macromolecules" with one half jointly to John B. Fenn and Koichi Tanaka "for their development of soft desorption ionisation methods for mass spectrometric analyses of biological macromolecules" and the other half to Kurt Wüthrich "for his development of nuclear magnetic resonance spectroscopy for determining the three-dimensional structure of biological macromolecules in solution". Aav, POKE Workshop, 12.12.2013 3 NMR active nuclei 2010 Saaremaa http://www.chem.wisc.edu/areas/reich/chem605/ 4 Aav, POKE Workshop, 12.12.2013 Strucutre detemination Kitahara We 1991 Riina Aav,* Tõnis Pehk, Sven Tamp,Toomas Tamm, Marina Kudrjašova, Omar Parve and Margus Lopp Magn. Reson. Chem. 2011, 49, 76–82 Aav, POKE Workshop, 12.12.2013 5 The Nobel Prize in Chemistry 2013 Martin Karplus, Michael Levitt, Arieh Warshel The Nobel Prize in Chemistry 2013 was awarded jointly to Martin Karplus, Michael Levitt and Arieh Warshel "for the development of multiscale models for complex chemical systems". Karplus equation M. Karplus JACS 1963 M. Karplus, J. Chem. Phys., 1959, 30, 11–15. 6 Aav, POKE Workshop, 12.12.2013 1 H-NMR (JHH)– for assignment of stereoisomers H3 H1 H6, H7 H5 H4, H8 7 5 + 6 4 3 Aav, POKE Workshop, 12.12.2013 1 7+ 2 Prediction of NMR parameters Correlation of full quantum chemical (B3LYP/6-31(d) calculation of JHH and JCH with experiment 6 isomers 3 isomers 64 JHH constants 88 JCH constants 3 isomers 3 isomers 3 2 55 JCH constants 33 JCH constants 10,0 10,0 R² = 0,9407 8,0 8,0 R² = 0,9097 , Hz , ) 6,0 Hz , 6,0 (C,H (C,H) J 4,0 4,0 J 3 2 2,0 2,0 Exp 0,0 Exp 0,0 compounds 1, 2, 3, 5, 6, 7 0,0 5,0 10,0 0,0 5,0 10,0 3 2 Aav et al. Magn. Reson. Chem. 2011 Calc J(C,H), Hz Calc J(C,H), Hz compounds 1, 2, 3 Aav, POKE Workshop, 12.12.2013 8 JC,P coupling constant as indicator of C-atom geometry <1 eq NaH JPC = 132.2 Hz JPC ~215 Hz 5 eq NaH 31P d = 41.4, 42.3, 43.0 ppm 13 C three peaks d ~ 46 ppm JPC ~215 Hz R. Aav, T. Kanger, T. Pehk, M. Lopp, Phosphorus, Sulfur, and Silicon, 2005, 180,1739–1748 Aav, POKE Workshop, 12.12.2013 9 Hexacyclinol story – year 2002 4 years later 37 steps, 3.6 g of product Received: November 14, 2005 Published online: February 9, 2006 10 1H-spectra published by La Clair 11 The same year- 2006 The structure of the natural product hexacyclinol was reassigned from endoperoxide 1 to the diepoxide 7 on the basis of calculated 13C chemical shift data using HF/3-21G geometries and mPW1PW91/6-31G(d,p) GIAO NMR predictions. These predictions correlate very well with experimental data for three other highly oxygenated natural products, elisapterosin B, maoecrystal V, and elisabethin A. Hexacyclinol is proposed to arise from acid-catalyzed rearrangement of panepophenanthrin in the presence of methanol. 12 ... jätkub Arvutuslike ja eksperimentaalsete 13C NMR nihete vahe 13 The same year- 2006 6 steps, 60.2 mg of product 14 ... continues 15 15 The same year - 2006 ... ... ... 16 2 years later 17 1 year later - 2009 An in-depth DFT computational investigation (B97- 2/cc-pVTZ level) of the 1H and 13C NMR spectra of the recently disputed natural substance hexacyclinol, including J(1H,1H) couplings, is presented. 18 Endgame for La Clair – year 2012 R.Aav - Spektroskoopia erikursus 19 P-derivatization Aav, POKE Workshop, 12.12.2013 20 Aav, POKE Workshop, 12.12.2013 21 8 years later Aav, POKE Workshop, 12.12.2013 22 1 year later in University of Illinois UC - 2008 - N N Bn H Cl + P Bn N P N N 1.KOtBu THF N N NBn N 2. H exane N N 3. BnN 3 31 P NMR δ 37.88 (202 MHz, CDCl3) N N N N P + N N P N N N N H - Br 31P NMR δ 16.46 31P NMR δ 36.87 (202 MHz, Benzene) (202 MHz, CD3CN) Aav, POKE Workshop, 12.12.2013 23 Aav, POKE Workshop, 12.12.2013 24 Quantitative analysis Aav, POKE Workshop, 12.12.2013 25 Complexation with molecular containers Chiral Cyclohexylhemicucurbit[6]uril (cycHC) Riina Aav, Elena Shmatova, Indrek Reile, Maria Borissova, Filip Topic, Kari Rissanen, Org. Lett. 2013, 3786-3789 Aav, POKE Workshop, 12.12.2013 26 Diffusion ordered spectroscopy (DOSY) (all-R)-cycHC O + (all-R)-cycHC H O H O CDCl3 Diffusion constant Diffusion H O H 1H chemical shift Aav, POKE Workshop, 12.12.2013 27 -1 Association constants Ka (M ) determined by DOSY RCOOH - Cl CDCl3 cycHC cycHC + HCOOH -1 Ka(rel) 97 ± 1 M -1 Ka(rel) 73.2 ± 0.5 M (R+S)-10 + cycHC -1 Ka(rel) 8.0 ± 0.5 M 10 13 -1 (all-R)-cycHC + C-NMR Ka(rel) 0.6 ± 0.5 M -1 S-10 Ka(rel) 20.1 ± 0.2 M -1 R-10 Ka(rel) 27.2 ± 0.8 M Aav, POKE Workshop, 12.12.2013 28 Examples of DOSY spectra: Analysis of biological samples Morris, G.A. and Barjat, H. (1997) in Methods for Structure Elucidation by High-Resolution NMR 29 (eds G.Y. Batta, K.E. Köve and C.S. Szantay Jr.), Elsevier, Amsterdam, pp. 209–226. Aav, POKE Workshop, 12.12.2013 30 Summary • With NMR variety of physical properties of organic compounds can be determined Fine structure assignment Quantitative content Interaction/reaction studies • Only NMR active nuclei give a signal • Data can be difficult to interpret Aav, POKE Workshop, 12.12.2013 31 Acknowledgement Tõnis Pehk Silver Suun Jüri Jarvet Sven Tamp Toomas Tamm Marina Kudrjašova Scott Eric Denmark Elena Shmatova Indrek Reile Maria Kuhtinskaja (end. Borissova) Filip Topić Kari Rissanen Estonian Science Foundation Tõnis Kanger Estonian Ministry of Education and Research Margus Lopp TUT basefinancing Marek Kõllo Academy of Finland National Doctoral Programme in Maria Kulp Nanoscience, Finland Anna-Liisa Peikolainen Mihkel Koel Aav, POKE Workshop, 12.12.2013 32 Aav, POKE Workshop, 12.12.2013 33 .