Luminescent, Redox-Active Diphenothiazine Dumbbells Expanded by Conjugated Arenes and Heteroarenes

• Published in: Journal of organic chemistry Vol. 75; no. 24; pp. 8591 - 8603
• Main Authors: Hauck, Martina, Turdean, Raluca, Memminger, Karin, Schönhaber, Jan, Rominger, Frank, Müller, T. J. J
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 17.12.2010; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Condensed benzenic and aromatic compounds; Electrochemistry; Exact sciences and technology; General and physical chemistry; Heterocyclic compounds; Heterocyclic compounds with n hetero atom and also o and/or s, se, te hetero atoms; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; ELECTRONIC-PROPERTIES; CROSS-COUPLING REACTIONS; 1ST SYNTHESIS; FLUORESCENCE; CATION-RADICALS; OLIGOPHENOTHIAZINES; ARYL; DERIVATIVES; PHENOTHIAZINE; OLIGOMERS; Nitrogen heterocycle; Phenothiazine derivatives; Luminescent material; Perylene derivatives; Thiophene derivatives; Suzuki-Miyaura cross-coupling; Pi electron; Aromatic compound; Redox system; Electron transmission; Chemical synthesis; Photoexcitation; Sulfur nitrogen heterocycle; Arene; Frontier orbital; Pyrazine derivatives; Anthracene derivatives; Suzuki coupling; Sulfur heterocycle; Electronic structure; Oxidation potential; Electrochemistry; Density functional method; Conjugated compound; Conformation; Excited state
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo101997t

Dumbbell-shaped diphenothiazines bridged by conjugatively linked (hetero)aromatic moieties were synthesized in a modular fashion by Suzuki−Miyaura coupling in good yields. The electronic structure was studied by DFT computations, determining the geometry optimized lowest energy conformers and scrutinizing the Kohn−Sham FMOs. The torsional deviation from coplanarity is predominantly influencing the electronic structure, i.e., by deviation from ideal overlap and maximal electron transmission. The reversible oxidation potentials assigned to the phenothiazinyl electrophores in most cases can thereby be qualitatively rationalized. All dumbbell-shaped diphenothiazines are strongly luminescent, which can be attributed to extended π-electron conjugation with considerable excited state electronic coupling as a consequence of large structural and electronic distributional changes upon photoexcitation.