Spin dynamics in Adamantane and Liquid Crystal 5CB Charaterized by Multiple Quantum Dipolar Evolution.

A.K. CHATTAH; C. SÁNCHEZ; P.R. LEVSTEIN; R.H. ACOSTA

Pacific Grove, California, USA

Conferencia; 49th ENC - Experimental Nuclear Magnetic Resonance Conference; 2008

In this work we present multiple quantum solid state NMR experiments to study the many-body dynamics of spin systems.  A new pulse sequence is designed to characterize the dipolar evolution encoded in different coherence orders in the Zeeman basis. Experiments were performed in polycrystalline Adamantane (infinite 1H  system)  and in the liquid crystal 5CB in the nematic mesophase (closed cluster). The difference in the proton-proton interactions in both systems is correlated with the behavior of the coherence order buildups. Spin counting measurements give information on the geometrical arrangement of spins and cluster formation. The experiment also provides insight on the sources of  decoherence during the evolution. A comparison between the evolution under dipolar and double quantum Hamiltonian is discussed. POSTER PRESENTADO POR AK CHATTAH