Structural elucidation (automatic determination of the structure of amolecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemblethe identified substructures. We devised a new m...Structural elucidation (automatic determination of the structure of amolecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemblethe identified substructures. We devised a new method which can avoid this pitfall by a systematicexamination of allowed ^(13)C chemical shifts ranges for all substructures chemically possible andcombined with a progressive pruning thanks to neighbouring relationships appearing from 2D NMR. Thismethod is explained by a detailed example.展开更多
The quantitative relationship between relative electrophoretic mobility in capillary electrophoresis for a series of 31 closely related alkylpyridines and their molecular structures was studied by using CODESSA. Acco...The quantitative relationship between relative electrophoretic mobility in capillary electrophoresis for a series of 31 closely related alkylpyridines and their molecular structures was studied by using CODESSA. According to the t test on the results, we found that the three most important descriptors affecting the mobility are the relative number of rings ( NR ), Min e n attraction for a C—N bond ( MEN ) and average complementary information index (ACIC) . With these structure descriptors a good three parameter linear model was developed to correlate the mobility of these compounds with their structures. This model can not only correctly predict the migration behavior of these compounds, but also find the structural factors which are responsible for the migration behavior of these compounds, thus can help to explain the separation mechanism of these compounds. The method used in this work can also be extended to the mobility structure relationship research of other compounds.展开更多
文摘Structural elucidation (automatic determination of the structure of amolecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemblethe identified substructures. We devised a new method which can avoid this pitfall by a systematicexamination of allowed ^(13)C chemical shifts ranges for all substructures chemically possible andcombined with a progressive pruning thanks to neighbouring relationships appearing from 2D NMR. Thismethod is explained by a detailed example.
文摘The quantitative relationship between relative electrophoretic mobility in capillary electrophoresis for a series of 31 closely related alkylpyridines and their molecular structures was studied by using CODESSA. According to the t test on the results, we found that the three most important descriptors affecting the mobility are the relative number of rings ( NR ), Min e n attraction for a C—N bond ( MEN ) and average complementary information index (ACIC) . With these structure descriptors a good three parameter linear model was developed to correlate the mobility of these compounds with their structures. This model can not only correctly predict the migration behavior of these compounds, but also find the structural factors which are responsible for the migration behavior of these compounds, thus can help to explain the separation mechanism of these compounds. The method used in this work can also be extended to the mobility structure relationship research of other compounds.
