Multiquantum NMR of quadrupole nuclei with strong pulses

✍ Scribed by Ago Samoson

• Book ID: 103032069
• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 211 KB
• Volume: 247
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)01293-0

✦ Synopsis

A three-pulse sequence readily generates detectable 3 quantum coherences in 1 = 3/2, and 3 and 5 quantum coherences in I = 5/2 spin systems.

The energy differences between the levels ]m) and I -m) of half-integer spin I = 3/2, 5/2,... quadrupole nuclei in a strong magnetic field are shifted by electric quadrupole interactions only to second order . In many practical cases the second-order modulations are relatively small and can be averaged by various mechanical sample reorientation methods . The averaged energy levels (in rotating coordinates), however, still depend on two unrelated interactions: on the isotropic value of chemical shielding o-(with carder offset o-o) Em ---( o" + trreference)m = tro m, (1) and on the isotropic second-order quadrupole shift 3 e2Qq/h (l+½n 2) Em= "~ 11(21-1)2vL ×[3mH-l(l+ l)]m