Synthesis, Electrochemical Reduction and Radical Anions of 2‐[Bis(4‐amino(nitro)phenyl)aminomethyl]‐9H‐thioxanthene‐9‐one Derivatives

Abstract

2‐[Bis(4‐amino(nitro)phenyl)aminomethyl]‐9H‐thioxanthene‐9‐ones and their S‐oxide derivatives have been synthesized, and their electrochemical reduction (ECR) in N,N‐dimethylformamide (DMF) and MeCN has been studied by cyclic voltammetry (CV). The thioxanthene‐9‐one group [Th(O)S] and thioxanthene‐9‐one S‐dioxide group [Th(O)SO2] determine the first one‐electron peak potentials of 2‐[bis(4‐aminophenyl)aminomethyl]‐9H‐Th(O)S/Th(O)SO2. The first peak potentials of the corresponding dinitro compounds are determined by the ratio of reduction potentials of bis(4‐nitrophenyl)amino and 9H‐thioxanthene‐9‐ones moieties. Radical anions (RA) of the synthesized compounds have been obtained by ECR in DMF and MeCN and characterized by EPR spectroscopy together with DFT calculations at the (U)B3LYP/6‐31 + G/PCM level of theory. Th(O)S and Th(O)SO2 groups are thermally stable up to 270 °C. The synthesized 2‐[bis(4‐aminophenyl)aminomethyl]‐9H‐Th(O)S/Th(O)SO2 are electrochemically active monomers for subsequent synthesis of the corresponding electroactive polyimides with thioxanthene‐9‐one based pendant groups for their applications in the design of nonvolatile memory storage devices. The pendant groups are characterized by low redox potentials and reversibility towards electron transfer.

Electrochemical Reduction of 1H‐Thioxanthene‐1,4,9‐trione and 3‐Methyl‐1H‐thioxanthene‐1,4,9‐trione – Representatives of a New Class of Heterocycles Related to Thioxanthenone

“…[7] Lately, compounds based on thioxanthen-9-one are being used in organic electronics as building blocks of novel thermally-activated polymers with delayed fluorescence for OLEDs production [8] and also as pendant groups of electro-active ambipolar polyimides, which are promising materials for applications in the polymer-based resistive memory technologies. [9][10][11][12] It was shown [13] that CÀ H fragments in 1,4-positions of the thioxanthen-9-one ring can be replaced with carbonyl groups by cyclization of arylsulfanylbenzoic acids obtained by the reaction of thiosalicylic acid with benzoquinone, 1,4-naphtho-and anthraquinones. This leads to the corresponding thioxanthene triones, in particular, to 1Hthioxanthene-1,4,9-trione (1 a, Figure 1).…”

“…Since 1H-thioxanthene-1,4,9-triones have rather low electrochemical reduction potentials, they can be potentially used as precursors of pendant groups in special electro-active polymers for practical application in polymer-based resistive memory technologies, as has been shown for 9H-thioxanthen-9-ones [9][10][11][12] . For this purpose, we synthesized compound 1 b.…”

“…Its methyl group can be used as a linker similar to 2-methyl-9H-thioxanthene-9-ones. [11] However, the presence of two functional OH-groups in the structures of compounds 2 a,b can be used to synthesize electro-active polymers containing thioxanthone-like structures as in-chain blocks. These potential practical applications of thioxanthene triones and their 1,4-dihydroxy derivatives motivated us to conduct an in-depth comparative ECR study of compounds 1 a,b and 2 a,b using a combination of electrochemical, optical, and EPR methods.…”

“…Thioxanthone (9 H ‐thioxanthen‐9‐one) and its derivatives found a number of practical applications in pharmacology [1–4] , biotechnology [5,6] and polymer science as initiators of photoinduced polymerization [7] . Lately, compounds based on thioxanthen‐9‐one are being used in organic electronics as building blocks of novel thermally‐activated polymers with delayed fluorescence for OLEDs production [8] and also as pendant groups of electro‐active ambipolar polyimides, which are promising materials for applications in the polymer‐based resistive memory technologies [9–12] . It was shown [13] that C−H fragments in 1,4‐positions of the thioxanthen‐9‐one ring can be replaced with carbonyl groups by cyclization of arylsulfanylbenzoic acids obtained by the reaction of thiosalicylic acid with benzoquinone, 1,4‐naphtho‐ and anthraquinones.…”

“…For this purpose, we synthesized compound 1 b . Its methyl group can be used as a linker similar to 2‐methyl‐9 H ‐thioxanthene‐9‐ones [11] . However, the presence of two functional OH‐groups in the structures of compounds 2 a,b can be used to synthesize electro‐active polymers containing thioxanthone‐like structures as in‐chain blocks.…”