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Calculation of some N and C nuclear shielding parameters for some ureas and thioureas |
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| Authors: | D J Reynolds G A Webb |
| Institution: | Department of Chemistry, University of Surrey, Guildford Gt. Britain Chimie Organique Physique, Université de Nantes, FRA 315, CNRS, 44072 Nantes France |
| Abstract: | Molecular orbital calculations using CNDO/S parameters are employed to determine bond-orders, charge-densities and the shielding of the 15N and 13C nuclei of a series of ureas and thioureas. For the sterically uncrowded molecules a linear relationship is noticed between the 15N chemical shifts and C---N bond-orders. When steric crowding occurs this simple relationship is no longer applicable. |
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