Correlation of ultraviolet spectra with structure via the integrated molecular and electronic transforms

✍ Scribed by Stephen P. Molnar; James W. King

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 154 KB
• Volume: 65
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1997)65:6<1047::aid-qua3>3.0.co;2-v

✦ Synopsis

The integrated molecular transform FT has been used for the m correlation of the structures of organic molecules with their physicochemical, thermodynamic, and pharmacological properties; it is also an excellent conformation index and functions as a discriminator of classical chemical structure types. In this study, Ž . it is used along with our recently introduced normalized molecular moment M , and n Ž . new structure indices, viz the integrated electronic transform FT , the integrated charge e Ž .

Ž . transform FT , and the electronic moment M , to establish appropriate models for the c e title subject. Initially, the principal absorption maxima in each of several series were regressed against the structural indices to determine which index best represented the structures in the context of the absorption data. The indices were then selectively regressed against the absorption data to generate absorbance estimation equations. In a series of multicyclic hydrocarbons, the FT functioned as a topological structure m discriminator as well as a structure surrogate. In the topological subsets, the FT and FT e c also were selectively useful. For a series of conjugated dienes, the FT and the M were m n statistically appropriate. In a series of substituted benzenes, the discrimination of halobenzenes was apparent and could be represented by either the FT , FT , or M m e e indices. For other variously substituted benzenes, the FT is the extant model and further m work with larger, structurally delineated series is warranted. For a series of monoalkylsubstituted nitrobenzenes, the FT and FT parameters are appropriate variables.

m e

Satisfactory correlation of molar absorptivities was not possible in this study as it would require absorption curve integration in the range where the maxima occurs.