Two-dimensional transferred-echo double resonance study of molecular motion in a fluorinated polycarbonate.
A two-dimensional version of the transferred-echo double resonance (TEDOR) experiment is introduced to measure strong heteronuclear magnetic dipolar interactions between rare spins. A quantitative description of this 2D-TEDOR experiment is given for an I-S pair of spins undergoing relative motion. 2D-TEDOR calculations are consistent with data for a calibration model: the directly bound 13C-31P pair in [3-13C]glyphosate, HO31(3)P13CH2NHCH2COOH. Analysis shows that the indirect spin-spin interaction and the dipole-dipole interaction have opposite signs in this system. The 2D-TEDOR experiment is then used to measure heteronuclear 13C-19F interactions in a fluorinated polycarbonate in which an aromatic proton is replaced by a fluorine on every fourth ring. Results from the 2D-TEDOR experiment show that the aromatic ring flips that occur in ordinary polycarbonate are blocked for a fluorinated ring.
Goetz
J M
JM
Department of Chemistry, Washington University, St. Louis, MO 63130, USA.
Wu
J H
JH
Yee
A F
AF
Schaefer
J
J
D002247:Carbon Isotopes; D002254:Carbonates / Q000737:chemistry*; D003198:Computer Simulation; D005465:Fluorocarbon Polymers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009038:Motion
D002247:Carbon Isotopes; D002254:Carbonates; D005465:Fluorocarbon Polymers