Multiple Quantum Coherence NMR and its Application to Molecular Structure Study.

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We developed the NMR method utilizing the multiple quantum coherence and applied it to the study of molecular structure. The multiple-relay correlation spectroscopy in which the single quantum coherence of a spin is transferred to other spins far apart four bonds was developed. This method was applied to cellooligosaccharides. It was found that this method is quite useful to separate out each single saccharide unit. Double quantum coherence echo correlated spectroscopy(DECSY) was developed. This method of 1H was applied to poly(vinyl alcohol) to determine equivalent methylene protons in the sequence of different stereoregularity. The <^(13)C> version of this method was also applied to the determination of stereoregularity of polypropylene oxide and the identification of cis and trans units of polybutadiene. Multiple quantum filter was utilized to separate out the two-spin system. Pure phase COSY became possible with double quantum filter. COSY with triple quantum filter was applied to poly (vinyl alcohol) to determine equivalent methylene protons.