EXPERT-SYSTEMS AS A TOOL FOR THE MOLECULAR-STRUCTURE ELUCIDATION BY SPECTRAL METHODS - STRATEGIES OF SOLUTION TO THE PROBLEMS

A great number of spectral tasks were solved to elaborate strategies o f molecular structure elucidation by expert systems based on the spect rum-structure correlations. The X-PERT system was used for this purpos e. The main assumptions of the structural-group spectral analysis and the main consequences of their violation are considered. The typical d ifficult situations met with, while problem solving, are investigated. A method for quality estimation of solutions to spectrum-structure pr oblems is suggested, The capacity of C-13 NMR chemical shift predictio n by the additivity rules for selection the true structure was verifie d, Strategies of the solution to a problem are suggested. The main fea ture of the offered approach is in a series of reiterations accompanie d by gradual growth of severity of the constraints which are imposed o n the answer structural file, It is concluded that X-PERT can be succe ssfully used for the structure elucidation of medium-sized molecules a s well as for teaching spectral methods to students.