P.E.HSQMBC: Simultaneous measurement of proton–proton and proton–carbon coupling constants

Measurement of long‐range heteronuclear coupling constants using the peak intensity in classical 1D HMBC spectra

“…Basically, there are two main NMR approaches for measuring long‐range 1 H– 13 C coupling constants efficiently: (a) 13 C‐edited 2D TOCSY‐based experiments and (b) long‐range 1 H– 13 C 2D correlation (HMBC/HSQMBC) experiments . Other type of experiments such as the excitation‐sculptured indirect‐detection experiment (EXSIDE), HEteronuclear Couplings from aSSCI Domain with Exclusive correlation spectroscopy (E.COSY)‐type cross‐peaks (HECADE), and ECOSY experiments have also been applied.…”

Broadband excitation pulses with variable RF amplitude‐dependent flip angle (RADFA)

“…Depending on the pulse sequence, the β ‐pulse is either used as a mixing pulse in correlation experiments or as an excitation pulse for effective usage of polarization. Typical experiments involving β ‐pulse mixing are the β ‐COSY, zz‐spectroscopy, the z‐COSY, the P.E.COSY, or the P.E.HSQC and variants thereof; the classical example for a β ‐pulse application, however, is the Ernst angle excitation that is used today in practically every 13 C‐1D experiment worldwide and which relies on a relaxation‐matched flip angle, which is also used in two‐dimensional correlation experiments like the SOFAST‐HMQC. …”

Broadband RF‐amplitude‐dependent flip angle pulses with linear phase slope

“…While most modern NMR experiments involve only effective flip angles of 90° and 180°, a number of applications also have the need of different flip angles. Examples are 60° and 120° pulses for effective transfer into double quantum coherences like in ADEQUATE experiments, or the application of so‐called β ‐pulses in one‐dimensional experiments, zz‐spectroscopy, various COSY experiments, and heteronuclear correlation experiments …”