Origin of the Correlation Time Dependence of Coherence Transfer Distortions in Rotating Frame Cross-Relaxation Spectra

✍ Scribed by Ranajeet Ghose; C.Anderson Evans; James H. Prestegard

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 203 KB
• Volume: 128
• Category: Article
• ISSN: 1090-7807
• DOI: 10.1006/jmre.1997.1221

✦ Synopsis

HOHAHA distortions in conventional (CW) ROESY experidition of maximum HOHAHA transfer. Thus, choosing a ments are known to be prominent when the frequency of the spintransmitter position where there are no crosspeaks perpenlock field is near the midpoint between the resonance frequencies dicular to the diagonal minimizes HOHAHA distortions in of a pair of coupled spins. That the disappearance of these distorconventional ROESY spectra. In this same publication Chan tions with offset from the midpoint is more rapid for large moleet al. report the observation of a molecular weight depencules than smaller ones is less widely known, and less well underdence of the range of transmitter positions over which the stood. We provide a quantitative explanation of the latter phenom-HOHAHA distortions occur. The effects drop off more rapenon using a combination of theory and numerical simulations.

idly for large molecules than for small molecules. This de-

The cause of this effect can be found in the differential relaxation pendency is of some practical utility, since avoiding the of the various magnetization modes which are involved in HO-HOHAHA distortions becomes easier for larger molecules.

HAHA transfer. These modes experience enhanced relaxation far from a Hartmann-Hahn match. This enhancement is larger for Only a qualitative explanation for this molecular weight demolecules which have long correlation times. ᭧ 1997 Academic Press pendence could be given at that time. Here we make that Key Words: ROESY; HOHAHA; correlation time; magnetization explanation more quantitative using a combination of theory modes; average relaxation time.

and numerical results utilizing the magnetic resonance simulation library GAMMA (8).