Correlating sideband patterns with powder patterns for accurate determination of chemical shift parameters in solid‐state NMR

Abstract

Powder patterns and sideband patterns have different strengths when it comes to using them to determine chemical shift parameters. Here, we show that chemical shift parameters can be determined with high accuracy by analysing the correlation pattern from a 2D experiment which correlates a powder pattern in the indirect dimension with a sideband pattern in the direct dimension. The chemical shift parameters so determined have greater accuracy than those obtained by analysing a sideband or powder pattern alone, for the same signal-to-noise ratio. This method can be applied for both resolved correlation patterns and to cases where two components share similar isotropic chemical shifts. The methodology is demonstrated in this paper, both theoretically and experimentally, on the (31)P signals of the bis-phosphonate drug, pamidronate.

Solid State NMR Spectroscopy

“…A method using correlation between the chemical-shift anisotropy (CSA) pattern and sidebands for accurate measurement of shift parameters has been reported (33). 1 H CSA measurements of hydrogen-bonded functional group using fast MAS have also been presented (34).…”

“…The disordered binding of Mg 2+ to the DNA-repair protein, apurinic/apyrimidic endonuclease 1, was discovered and characterized using lowtemperature 25 Mg NMR (79). With the use of the widebanduniform-rate-smooth-truncation (WURST) sequence, population transfer from the satellite transitions to the central transition made it possible to measure the 33 S spectrum of the natural-abundance complex, (CH 3 NH 3 ) 2 WS 4 , to obtain the parameters of all three overlapped resonances (80). The availability of ultrahigh magnetic fields allows one to dramatically improve the resolution of 35 Cl resonances, as is shown by recently reported spectra of organic hydrochloride salts at 18.8 T (81) and halide ionic liquids at 21.1 T (82).…”