RESUMO
A simple to use nuclear magnetic resonance analysis method has been tested on complex 1 H, 19 F, and 13 C multiplets. This open-source line-shape analysis method analysis of total lineshape (ANATOLIA)1 provides some significant advantages over traditional assign-iterate methods of NMR spectral analysis by avoiding false minima and progressing optimisation to the global minimum. The target molecules are 1-perfluorotol-4-yl-2-perfluorotol-4-yl-oxymethyl-1H-benzimidazole (molecule-I) and 1-tetrafluoropyrid-4-yl-2-tetrafluoropyrid-4-yl-thio-1H-benzimidazole (molecule-II) which were produced as part of a family of fluorinated drug scaffolds prepared for anticancer and antiparasitic screening. Spectra display significant second-order effects with 1 H Δδ = 3.68 and 4.67 Hz for the aromatic hydrogen "triplets", with 19 F 4 JAA' , 4 JBB' , 4 JXX' , and 4 JYY' coupling constants range from +4.8 to -14.0 Hz and for 13 C-isotopomers 19 F Δδ of up to 111.56 Hz. A spin-system of six coupling nuclei (Ha Hb Hc Hd FY FY' ) was analysed in 12 s, a spin-system of nine coupling fluorine nuclei (AA'BB'CCC-YY') was analysed within 2 min, and 10 coupling nuclei (XX'YY'ZZZ-BB'-Hd ) was optimised in 6 min using a laptop computer. ANATOLIA was also robust enough to be able to yield accurate spectral values from inaccurate input values. In both compounds, a fluorine-fluorine coupling constant was identified between the two fluoro-aromatic rings (FBB' and FYY' ) of +4.05 and +4.67 Hz and attributed to a through-space interaction. Ab initio structure optimisations and coupling constant calculations provided useful input data for spectral analysis. A modern 19 F nuclear magnetic resonance spectrum of perfluorotoluene (octafluorotoluene) and analysis from 1975 was used as a test data set to assess ANATOLIA.