title: Suppression of phase and amplitude J(HH) modulations in HSQC experiments.
abstract: The amplitude and the phase of cross peaks in conventional 2D HSQC experiments are modulated by both proton-proton, J(HH), and proton-carbon, (1)J(CH), coupling constants. It is shown by spectral simulation and experimentally that J(HH) interferences are suppressed in a novel perfect-HSQC pulse scheme that incorporates perfect-echo INEPT periods. The improved 2D spectra afford pure in-phase cross peaks with respect to (1)J(CH) and J(HH), irrespective of the experiment delay optimization. In addition, peak volumes are not attenuated by the influence of J(HH), rendering practical issues such as phase correction, multiplet analysis, and signal integration more appropriate.
authors.affiliation: Servei de Ressonància Magnètica Nuclear, Facultat de Ciències, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Catalonia, Spain; Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Catalonia, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Castañar
authors.forename: Eduard
authors.initials: E
authors.lastname: Sistaré
authors.forename: Albert
authors.initials: A
authors.lastname: Virgili
authors.forename: R Thomas
authors.initials: RT
authors.lastname: Williamson
authors.forename: Teodor
authors.initials: T
authors.lastname: Parella
keywords: HSQC; J(HH) modulation; NMR; perfect HSQC; pure in-phase signals