Spectroscopic, Theoretical, and Electrochemical Studies of 1,2-Dithiins

Abstract

The lowest oxidation potentials for 1,2-dithiins are in the range of 0.67-0.96 V in acetonitrile and 0.81-1.04 V in dichloromethane. These oxidation potentials are less anodic than expected based on the ionization potentials of 1,2-dithiin determined by photoelectron spectroscopy. Theoretical calculations suggest that the reason for this difference is a change in optimized geometry between 1,2-dithiin and its oxidized species.

Diacenaphtho[1,2-c:1′,2′-e]-1,2-dithiin: synthesis, structure and reactivity

“…These distances are similar to those found in the compounds Pt(COD)(C 6 H 4 S 2 ) (Pt-S ¼ 2.264 (5) A A) [17] and Mn 2 (CO) 7 Pt(PPh 3 ) 2 (l 3 -S) 2 …”

“…Compound 1 consists of a thiophene with each double bond annulated by an acenaphthylene molecule. The three carbon-carbon bond distances in the thiophene ring are not significantly different (C(1)-C(2) ¼ 1.404 (5) A A, C(2)-C(3) ¼ 1.404(5) A A, and C(3)-C(4) ¼ 1.392 (5) A A), which suggests that the 6p electrons are fully delocalized. Compound 3 is a 2,3-dihydro-1,4-dithiin also annulated by two acenaphthylene molecules and the two hydrogen atoms are cis to each other.…”

“…1,2-Dithiins such as the thiarubrines can be found in plants and show extensive biological activity [4]. These compounds are also of interest to theoretical chemists because they adopt a non-planar twisted geometry and are antiaromatic [5][6][7]. Their high reactivity and structural instability have limited the synthesis and characterization of derivatives of these naturally occurring molecules [8,9].…”