Synthesis, Characterization And Theoretical Study Of The Chemical Reactivity Of New Cyclic Sulfamides Linked To Tetrathiafulvalene

Résumé: The synthesis of title compounds has been carried out by condensation via Wittig-type reaction of the hexafluorophosphate salt with the phosphonate ester to gives the desired nitro-tetrathiafulvalene 1, then the nitro group was reduced into an amino group 2. Linear sulfamide 3 was prepared in two-step reaction sequence starting from chlorosulfonyl isocyanate and absolute tert-butyl alcohol. Cyclic sulfonamide-TTF 4 was obtained under basic conditions, and then selective cleavage of the protective group gives compound 5. Finally, alkylated cyclic sulfamide linked to tetrathiafulvalene 6-7 were obtained by alkylation methods. All compounds were characterized by 1HNMR and mass spectroscopy. The electron donor ability has been measured by cyclic voltammetry technique. A detailed DFT study based on B3LYP/6-31G (d,p) of electronic properties was also presented. In molecular electrostatic potential, the negative charge covers the nitro and sulfamide function, while the positive region is over the hydrogen atoms of the amine and sulfonamide rings. The calculated HOMO and LUMO energy reveals that the charge transfers occurring within the molecule. The chemical reactivity parameters reveal that tetrathiafulvalene 1 is highly reactive which facilitated the desired formation of cyclic sulfonamide. First hyperpolarizability (βtot) shows that compounds 1 and 5 are good candidates as a NLO material.

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