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The effects of intramolecular and intermolecular coordination on 31 P nuclear shielding: phosphorylated azoles
Author(s) -
Chernyshev Kirill A.,
Larina Ludmila I.,
Chirkina Elena A.,
Krivdin Leonid B.
Publication year - 2012
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.2854
Subject(s) - intramolecular force , intermolecular force , chemistry , electromagnetic shielding , computational chemistry , crystallography , molecule , stereochemistry , organic chemistry , quantum mechanics , physics
The effects of intramolecular and intermolecular coordination on 31 P nuclear shielding have been investigated in the series of tetracoordinated, pentacoordinated and hexacoordinated N ‐vinylpyrazoles and intermolecular complexes of N ‐vinylimidazole and 1‐allyl‐3,5‐dimethylpyrazole with phosphorous pentachloride both experimentally and theoretically. It was shown that either intramolecular or intermolecular coordination involving phosphorous results in a dramatic 31 P nuclear shielding amounting to approximately 150 ppm on changing the phosphorous coordination number by one. A major importance of solvent effects on 31 P nuclear shielding of intramolecular and intermolecular complexes involving N → P coordination bond has been demonstrated. It was found that the zeroth‐order regular approximation–gauge‐including atomic orbital–B1PW91/DZP method was sufficiently accurate for the calculation of 31 P NMR chemical shifts, provided relativistic corrections are taken into account, the latter being of crucial importance in the description of 31 P nuclear shielding. Copyright © 2012 John Wiley & Sons, Ltd.