NMR - Nuclear Magnetic Resonance(NMR Spectroscopy Determine...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Chem 341 - NMR & Unknowns 1 • Week 1 - Worksheet on NMR • Week 2 - Use FT-IR and 1 H NMR spectra to solve structure. Nuclear Magnetic Resonance (NMR) Spectroscopy & Determine the Structure of an Unknown Organic Compound Important Concepts • Theory of NMR • De±nitions: up/down±eld, ppm, spins, chemical shift • Spin-Spin splitting and n+1 rule • Unsaturation number • Spectroscopic identi±cation of organic compounds
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Chem 341 - NMR & Unknowns 2 Nuclear Magnetic Resonance (NMR) Spectroscopy Photosource: † wikipidea; ¶ New York Times; ‡ nobelprize.org Uses of NMR: - determine connectivity of atoms - binding constants - diffusion constants - examine intermolecular interactions Chemists quickly realized the importance for structural characterization. Richard Ernst (1933 - ) Born in Winterthur, Switzerland Varian and ETH-Zurich Nobel Prize - 1991 Kurt Wüthrich (1938 - ) Born in Aarberg, Switzerland Scripps and ETH-Zurich Nobel Prize - 2002 Basic research is a great investment! But it takes time. Historical Perspective Felix Bloch (1905 - 1983) Born in Zurich Switzerland Stanford University Nobel Prize - 1952 Edward Purcell (1912 - 1997) Born in Taylorsville, IL USA MIT - 1945 w/Pound & Torrey Nobel Prize - 1952 Two physicists thought of an interesting experiment. Sir Peter Mansfield (1933 - ) Born in London England University of Nottingham Nobel Prize - 2003 Magnetic Resonance Imaging (MRI) is revolutionizing medicine and psychology Paul Lauterbur (1929 - 2007) Born in TifFn, OH USA U. IL-Urbana Champaign Nobel Prize - 2003
Background image of page 2
Chem 341 - NMR & Unknowns 3 Magnetic Field B o Energy 1 2 + 1 2 How Does NMR Work? Light Source Sample Detector Photosource: ‡ www.cem.msu.edu/~reusch; ¶ Varian, Inc.; †www.swimmingholes.org Δ E α B o swimming upstream takes more energy + 1 2 1 2 • Some nuclei have a magnetic spin. • In the absence of an external B o , the spins are equal in energy. • NMR active: 1 H, 13 C, 31 P, 19 F, etc. Superconducting magnet Radio Frequency • Application of a B o causes the energy of spins aligned with the ±eld to decrease, and those aligned against B o will increase. B o
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Chem 341 - NMR & Unknowns 4 Acquisition of an NMR Spectrum + 1 2 1 2 B o R F pulse + 1 2 1 2 Spins are ±ipped B o Detector Fourier Transform (FT) 0 ppm 10 δ δ = chemical shift [Frequency Domain] time Intensity Free Induction Decay (FID) [Time Domain] nucleus is in resonance
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 16

NMR - Nuclear Magnetic Resonance(NMR Spectroscopy Determine...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online