Chemical shift

{
  "id": "MLC-T-CHM-001963",
  "term": "Chemical shift",
  "field": "Chemistry",
  "definition": "The difference in the resonance frequency of a nucleus in a nuclear magnetic resonance (NMR) spectrum compared to a reference standard, expressed in parts per million (ppm). This variation arises from the shielding or deshielding effects of surrounding electrons, which are influenced by the local chemical environment. It provides information about the molecular structure and functional groups present.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "resonance",
    "dilute solution",
    "nucleus",
    "shielding",
    "spectroscopy"
  ],
  "references": [
    "Green Book, 3rd ed., p. 29 (https://doi.org/10.1039/9781847557889)",
    "PAC, 2001, 73, 1795. 'NMR nomenclature. Nuclear spin properties and conventions for chemical shifts(IUPAC Recommendations 2001)' on page 1807 (https://doi.org/10.1351/pac200173111795)",
    "PAC, 2008, 80, 59. 'Further conventions for NMR shielding and chemical shifts (IUPAC Recommendations 2008)' on page 61 (https://doi.org/10.1351/pac200880010059)",
    "PAC, 1979, 51, 2243. 'General aspects of trace analytical methods - IV. Recommendations for nomenclature, standard procedures and reporting of experimental data for surface analysis techniques' on page 2247 (https://doi.org/10.1351/pac197951112243)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/chemical-shift/"
}