16
Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of Fundamental Research Homi Bhabha Road, Mumbai

Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

  • Upload
    others

  • View
    6

  • Download
    0

Embed Size (px)

Citation preview

Page 1: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Pulsed NMR Spectroscopy

R. V. Hosur

Department of Chemical SciencesTata Institute of Fundamental Research

Homi Bhabha Road, Mumbai

Page 2: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Fourier Transform (FT) NMR

z Bo

Field

Vector Summation

y

x

z

y

x

Page 3: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Fourier transform NMR

Br

B1

Beff

Mo

Bri = Bi – ωRF / γ

If B1 >> Bri, then Beff ~ B1 for all i.

ωeff = γ Beff

Rotating frame ωri = ωi – ωRF

Page 4: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Beff ~ B1

Pulse width (τ) = time for which B1 is applied

Flip angle (θ) = γ B1 τ

Page 5: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

y

x

z

y

x

B1

Application of RF rotates the magnetisation

M

M

90o pulse

Page 6: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Fourier Transform NMR

f(t)FT F(ω)

Page 7: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Fourier Transform NMR

R. R. Ernst and W. A. AndersonRev. Scientific Instrum. 37, 93 (1966)

Page 8: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

1 mM Lysozyme

Resolution

Page 9: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Water suppression

H2O : 110 M in protons

Protein : 1 mM

Dynamic range problem

PresaturationJump and returnFlipbackWatergate….Excitation sculpting

Page 10: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of
Page 11: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of
Page 12: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of
Page 13: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Excitation Sculpting

π/2 – G1 − R – G1 – G2 – R – G2 - acquire

R = (πsel – π)

Page 14: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of
Page 15: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Spin EchoRefocuses chemical shift evolution

Method for T2 measurements: SE amplitude is dictated by T2 relaxation

Page 16: Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical ...iupab/WS_2009_pulsed NMR.pdf · Pulsed NMR Spectroscopy R. V. Hosur Department of Chemical Sciences Tata Institute of

Inversion recovery T1 measurement