Recent Developments in Absolute Shielding Scales for NMR Spectroscopy

Calculating nuclear magnetic resonance chemical shifts in solvated systems

“…If the absolute shielding of the nucleus in question (the shielding of the bare nucleus) is known, this absolute shielding scale can be used to convert magnetic shielding to chemical shift. Absolute shielding scales can be determined from molecular beam experiments, and absolute shielding scales have been reported for several nuclei . However, many of these shielding scales were determined in the nonrelativistic limit before it was determined how important relativistic corrections to shielding of even light nuclei are, and will need to be revised…”

Quantum chemical calculations of77Se and125Te nuclear magnetic resonance spectral parameters and their structural applications

“…More comprehensive description of the theoretical and physical aspects of nuclear shielding, including the problem of MKB, is presented in the book chapter by Jameson and Dios. [256] Among the most popular four-component methods are the relativistic random phase approximation (RRPA), [71,[257][258][259] which is equivalent to the timedependent Dirac-Hartee-Fock (DHF) method, and the four-component DFT (4c-DFT) or Dirac-Kohn-Sham (DKS) method. [260,261] For the critical assessment of different relativistic four-component approaches to SCs, we refer to the review by Xiao et al, [66] where both formal and numerical analyses have been carried out on various exact and approximate variants of the fourcomponent relativistic theory for nuclear magnetic shielding constants.…”

“…High-quality theoretical reviews on NMR nonrelativistic computational basics repeatedly emerge throughout the literature. [39][40][41][42][43][44][45][46][47][48][49][50][51] Theoretical consideration of the NMR parameters within the framework of the relativistic theory has been initiated by Pyper, [52] Pyper and Zhang, [53] Zhang and Webb, [54] Pyykkö, [55] and Pyykkö et al [56] in the 1980s and proceeded by Nakatsuji et al, [57][58][59][60][61][62] Fukui et al, [63,64] Liu et al, [65][66][67][68][69][70] Aucar et al, [71][72][73][74][75][76][77][78] Vaara et al, [79][80][81][82] Autschbach et al, [83][84][85][86]…”

Investigating solvent effects on the magnetic properties of molybdate ions () with relativistic embedding

“…In most cases, what is measured in experiments is not σ K but rather a signal relative to a chosen reference species, the chemical shift δ K , although in recent years, experimental advances have revived interest in determining absolute shielding scales. [1][2][3] NMR spectra can be quite difficult to interpret. The difficulties may come from the complexity due to the size of the composition of the system (species in solution, disordered materials, etc.…”