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Tritium nuclear magnetic resonance spectroscopy. Part 11. Further consideration of referencing, isotope effects and coupling constants: Preparation of [ 3 H]tetramethylsilane
Author(s) -
Bloxsidge James P.,
Elvidge John A.,
Jones John R.,
Mane Ramachandra B.,
Saljoughian Manouchehr
Publication year - 1979
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270121006
Subject(s) - tetramethylsilane , geminal , coupling constant , chemistry , kinetic isotope effect , chemical shift , carbon 13 , methylene , isotope , nuclear magnetic resonance spectroscopy , analytical chemistry (journal) , tritium , deuterium , nuclear magnetic resonance , spectroscopy , radiochemistry , atomic physics , stereochemistry , organic chemistry , nuclear physics , physics , particle physics , quantum mechanics
Abstract Small discrepancies between 3 H and 1 H chemical shifts in organic compounds led to the finding that the ratio of Larmor frequencies ω T /ω H depends on the carbon‐hydrogen bond hybridisation. The ‘best’ ratio for ghost referencing of 3 H NMR spectra was then determined from measurements on purified partially tritiated TMS as 1.066639738±2 × 10 −9 . Some 3 H isotope effects on chemical shifts are listed and the 3 H isotope effect on the methylene geminal coupling constant in benzyl methyl sulphoxide is measured. Use of 2 H in the measurement of 2 J (HH) coupling constants has inherent disadvantages, overcome by use of 3 H substitution.