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Application of DPFGSE‐ROE to calixarene derivatives under conditions near NOE zero‐crossing †
Author(s) -
Bauer Walter,
Soi Antonio,
Hirsch Andreas
Publication year - 2000
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/1097-458x(200007)38:7<500::aid-mrc685>3.0.co;2-0
Subject(s) - chemistry , calixarene , zero (linguistics) , zero crossing , computational chemistry , stereochemistry , organic chemistry , thermodynamics , molecule , physics , linguistics , philosophy , power (physics)
In a modification of the well‐established DPFGSE‐NOE method, the mixing period is replaced by a spin‐lock sequence (DPFGSE‐ROE). Similar to conventional one‐and two‐dimensional ROE applications, the NOE is positive throughout, irrespective of the molecular correlation time. For the two calixarene derivatives 1 and 2 conventional difference NOE spectroscopy and DPFGSE‐NOE yield negative NOEs, indicating ωτ c > 1.12. By contrast, DPFGSE‐ROE leads to strong positive enhancements. Indirect (transferred) NOEs may be identified by their negative sign under these conditions. Copyright © 2000 John Wiley & Sons, Ltd.