Structural study of sulfamic acid at 4.2 K by ENDORhyphen;detected NMR

摘要

The electronndash;nuclear double resonance method (ENDOR) is used to obtain greatly enhanced NMR signals from the distant deuterium nuclei of perdeuterated sulfamic acid (ND3SO3) in single crystals at 4.2 K. The structural information is obtained by measuring the quadrupole coupling tensors of the deuterium atoms and their direction cosines. There is very good agreement between the Nndash;D bond angles derived from these ENDORhyphen;detected NMR (EDNMR) results and bond angles from neutron diffraction data at 78 K. Relationships between the deuterium quadrupole constants and Nndash;D and Dsdot;sdot;sdot;O bond lengths are derived and discussed.