Organosulfur Materials with High Photo- and Photo-Oxidation Stability: 10-Anthryl Sulfoxides and Sulfones and Their Photophysical Properties Dependent on the Sulfur Oxidation State

Abstract

While few studies show only symmetrical and poorly mono-SOn (n = 0–2) substituted acenes, in this study, we present a synthesis of a new group of unsymmetrical, significantly substituted derivatives, which revealed unique photophysical properties. Both sulfides (S), sulfoxides (SO) and sulfones (SO2) showed very high photochemical stabilities, unusual for these groups, during UV-irradiation at 254/365 nm (air O2 and Ar), which was higher than any found in the literature. For the (S)/(SO) series (254 nm), the stabilities of 80–519 min. (air O2 and Ar) were found. At 365 nm, stabilities of 124—812 min./(air O2) for (S)/(SO) and higher for (SO2) were observed. Photoluminescence lifetimes of (SOn) of the lower anthryl symmetry remained in the following order: (SO2) < (S) < (SO); those with full symmetry were in the following order: (S) < (SO) < (SO2). The enhanced photostability was explained with DFT/MS/Hammett’s constants, which showed the leading role of the SOn groups in stabilization of HOMO/LUMO frontier orbitals. The SOn (n = 0–2) substituted acenes turned out to be tunable violet/blue/green emitters by oxidation of S atoms and the introduction of rich substitution.

The First Example of the Friedel–Crafts Cyclization Leading to (10-Hydroxy-9,10-dihydroanthr-9-yl)phosphonium Salts without the Expected Bradsher Dehydration

“…The mixture of alcohol and phosphine in the presence of acid HA spontaneously cyclized to give products 11A-16A (A = anion) due to the presence of the ortho-acetal function, which, under acidic conditions, enabled the Friedel-Crafts (F-C) cyclization. The products were not the expected anthracenes III, as was the case during the previously described intramolecular hetero-Friedel-Crafts-Bradsher reactions [15][16][17], but 9,10-dihydroanthrols with a non-aromatic middle ring containing both 9-hydroxyl and 10-phosphonium groups. The subsequent Bradsher dehydration is usually the next step after the F-C reaction leading to the aromatic system, but not in this case [24].…”

“…Earlier, we elaborated a new approach to mono-hetero (Z = OR, SR)-substituted acenes IV via the hetero-Friedel-Crafts-Bradsher (F-C-B) cyclization of ortho-O,O-acetals, S,S-dithioacetals and O,S-thioacetals II obtained from diarylmethanols I [14][15][16][17]. In this reaction, a new benzene ring, fused to two other (hetero)aromatic moieties, ArI and ArII, is formed to give acenes IV (Scheme 1, path a).…”

Comprehensive Review on Synthesis, Properties, and Applications of Phosphorus (PIII, PIV, PV) Substituted Acenes with More Than Two Fused Benzene Rings

“…Apart from our preliminary work [ 70 , 71 ], this review showed, practically, a lack of works devoted to the highly substituted acene systems. It is noteworthy that highly substituted acenes containing thioorganic substituents showed extremely high thermal and photochemical stabilities, properties that would be interesting to verify for acenes with organophosphorus substituents [ 101 , 102 ]. Furthermore, the absence of hetero(S, Se)-analogs of phosphonates and phosphates was recorded during the reviewed period, which additionally opens the way for further research in this area.…”

O,S-Acetals in a New Modification of oxo-Friedel–Crafts–Bradsher Cyclization—Synthesis of Fluorescent (Hetero)acenes and Mechanistic Considerations

“…Anthracene and its derivatives are particularly attractive due to high thermal stability [ 3 ], relatively good solubility, low price, blue photoluminescent [ 4 ] and electroluminescent properties [ 5 ]. Many blue-light-emitting materials with an anthracene core structure [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ] have been developed; however, deep blue is still in demand due to the lack of electrically and photochemically stable light-emitting materials [ 19 , 20 ].…”