Generation of Aromatic (Dehydro)benzoannulene Dications Stabilized by Platinum Catecholate Complexes

Abstract

Ad ehydrobenzo [12]annulene attached by three platinum catecholate units is oxidized chemically or electrochemically to generate mono-, di-, and trications. Similarly,ap latinum catecholate complex with ad ibenzo [8]annulene framework also generates mono-and dications upon oxidation. On the basis of theoretical and spectroscopic studies with respectt oe nergetic, structural, and magnetic criteria, these dications are deduced to be aromatic, thus demonstrating an ew methodf or stabilizing aromatic dications.Aromaticity has been asubjectofinterest over many decades [1]

Oxidation of a Dithieno[3,4‐b:3′,4′‐d]thiophene Cyclic Dimer Containing a Planar Cyclooctatetraene Ring: Retention of High Antiaromaticity During Reactions

“…Thus far, only one study has been reported on the NMR observation of planar COT dication, which was made possible by the direct two‐electron oxidation of di‐ and tetra‐substituted COTs with SbF 5 in SO 2 ClF at low temperatures . The other NMR observations of COT dication were attained using COT tetra‐annelated with bicyclo[2.2.2]octane units or platinum catecholate complex of dibenzo‐COT . For the bicyclo[2.2.2]octane‐annelated COT, the COT dication with tub‐structure could be generated by one‐electron oxidation of the corresponding COT radical cation salt with SbF 5 in CD 2 Cl 2 at low temperatures.…”

“…[42] The other NMR observations of COT dication were attained using COT tetra-annelated with bicyclo[2.2.2]octane units [43] or platinum catecholate complex of dibenzo-COT. [44] For the bicyclo[2.2.2] octane-annelated COT, the COT dication with tub-structure could be generated by one-electron oxidation of the corresponding COT radical cation salt with SbF 5 in CD 2 Cl 2 at low temperatures. Thus, in the present study, we attempted to generate dication 2 Mes by both direct two-electron oxidation of 2 Mes and one-electron oxidation of 2 Mes * + SbCl 6 À with SbF 5 in CD 2 Cl 2 at low temperatures.…”

Theoretical Study on the Structures, Electronic Properties, and Aromaticity of Thiophene Analogues of Anti-Kekulene

“…Polycyclic compounds consisting of aromatic and anti-aromatic rings are a subject of interest because of their unique optical and electronic properties that originate from modulated (anti-)aromaticity [1][2][3][4][5][6][7][8]. Examples of these compounds include biphenylene (Figure 1a), which consists of two benzene rings and a four-membered ring (4MR) [9,10].…”

“…Moreover, it modulates optoelectronic properties and intermolecular interaction modes [35][36][37][38][39][40][41]. For instance, octathia [8]circulene (sulflower) [42], in which eight benzene rings of a saddle-shaped [8]circulene [43,44] are fully replaced with thiophene rings, has a planar structure [45]. Its one-dimensional π-stacking column with short intermolecular sulfur-sulfur contacts in the crystalline state exhibits a reasonable field-effect transistor property [46,47].…”