title: A systematic approach for optimizing the robustness of pulse sequence elements with respect to couplings, offsets, and B1-field inhomogeneities (COB).
abstract: Robust experiments that cover a wide range of chemical shift offsets and J-couplings are highly desirable for a multitude of applications in small molecule NMR spectroscopy. Many attempts to improve individual aspects of the robustness of pulse sequence elements based on rational and numerical design have been reported, but a general optimization strategy to cover all necessary aspects for a fully robust sequence is still lacking. In this article, a viable optimization strategy is introduced that covers a defined range of couplings, offsets, and B(1)-field inhomogeneities (COB) in a time-optimal way. Individual components of the optimization strategy can be optimized in any adequate way. As an example for the COB approach, we present the (1)H -(13)C-COB-INEPT with transfer of approximately 99% over the full carbon and proton bandwidth and (1)J(CH) -couplings in the range of 120-250 Hz, which have been optimized using efficient algorithms derived from optimal control theory. The theoretical performance is demonstrated in a number of corresponding COB-HSQC experiments.
authors.affiliation: Institute of Organic Chemistry and Institute for Biological Interfaces, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ehni
authors.forename: Burkhard
authors.initials: B
authors.lastname: Luy
mesh_terms: D000465:Algorithms; D000480:Alkynes / Q000737:chemistry*; D001547:Benzaldehydes / Q000737:chemistry*; D005561:Formates / Q000737:chemistry*; D005563:Formic Acid Esters / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D011422:Propionates / Q000737:chemistry*; D012015:Reference Standards
chemical_list: D000480:Alkynes; D001547:Benzaldehydes; D005561:Formates; D005563:Formic Acid Esters; D011422:Propionates; C510888:ethyl formate; C030544:formic acid; C011537:propiolic acid; C045941:ethyl vanillin