Rigorous Deduction Theory for Assignment of Multidimensional NMR Spectra Using the Independent Spin Coupling Network Approach

The concept of an ISNet (independent spin network), used to process various molecular connectivities which can be observed from multidimensional NMR spectra, is proposed. The conventional one-dimensional spectrabased computer-assisted structural elucidation (CASE) methods are based upon the correlation of subspectra substructure which is often ambiguous. However, modern multidimensional NMR experiments offer us abundant molecular spin coupling connectivity information. This information can be directly or indirectly mapped to real chemical structure or substructure. This fact is known as “the correlation of spectra patterns and structures”, where pattern implies connectivity. ISNets are the general graph theoretical representation for these patterns. By means of systematic graph theory and fuzzy mathematical analysis, a rigorous deduction theory for general purpose structural elucidation from multiple-dimensional NMR spectra is presented.