ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The symmetric part of the 31P NMR chemical shielding tensor was determined in a single crystal of 2-aminoethylphosphonic acid (AEP). The principal values, relative to 85% H3PO4, are σ11=87.1, σ22=15.6, and σ33=−47.5 ppm. Four orientations of the chemical shielding tensor on the molecule are possible, but only one of them shows correlation with the bond directions. The two most shielded components of the tensor lie almost in the plane containing the two P=O bonds, with σ22 approximately bisecting the O–P–O angle and σ33 roughly along the O–O connecting vector, leaving the phosphorus relatively deshielded in the perpendicular σ11 direction. The results can be correlated with the electron density distribution around the phosphorus atom, as determined by the bonding pattern of the phosphonate. A comparison is made with 31P NMR chemical shielding tensors in analogous phosphorus-containing compounds.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.452564
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