Residual dipolar couplings of soft solids by accordion magic sandwich

• Published in: Chemical physics letters Vol. 375; no. 3; pp. 406 - 412
• Main Authors: Demco, D.E., Fechete, R., Blümich, B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 03.07.2003; Elsevier Science
• Subjects: Applied sciences; Atomic and molecular physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrical, magnetic and optical properties; Exact sciences and technology; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Molecular properties and interactions with photons; Nuclear magnetic resonance and relaxation; Nuclear resonance and relaxation; Organic polymers; Physicochemistry of polymers; Physics; Properties and characterization; Spin echoes; Van Vleck moments; Adamantane; Polymer networks; Theoretical study; Natural rubber; Spin echo; Solid phase; Experimental study; NMR spectroscopy; Dipole interactions; Organic compounds; Pulse sequence
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/S0009-2614(03)00874-1

Residual dipolar coupling are important source of information about structure and molecular motions of soft solids. A new method, accordion magic sandwich is introduced, to measure these couplings in terms of residual van Vleck moments. A magic sandwich of variable duration leads to a Hahn echo which samples the shape of the magic echo. In this way residual dipolar couplings can be determined model free without contribution of inhomogeneous spin interactions and transverse magnetization relaxation. The method was tested on adamantane and on series of samples from cross-linked natural rubber.