title: Electron-Poor Thiophene 1,1-Dioxides: Synthesis, Characterization, and Application as Electron Relays in Photocatalytic Hydrogen Generation.
abstract: The synthesis and characterization of electron-poor thiophene 1,1-dioxides bearing cyanated phenyl groups are reported. The electron-accepting nature of these compounds was evaluated by cyclic voltammetry, and highly reversible and facile reductions were observed for several derivatives. Moreover, some of the reduced thiophene dioxides form colorful anions, which were investigated spectroelectrochemically. Photoluminescence spectra of the electron-deficient sulfones were measured in CH2 Cl2, and they emit in the blue-green region with significant variation in the quantum yield depending on the aryl substituents. By expanding the degree of substitution on the phenyl rings, quantum yields up to 34 % were obtained. X-ray diffraction data are reported for two of the thiophene 1,1-dioxides, and the electronic structure was probed for all synthesized derivatives through DFT calculations. The dioxides were also examined as electron relays in a photocatalytic water reduction reaction, and they showed potential to boost the efficiency.
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania, 15213 (USA).
authors.forename: Chia-Hua
authors.initials: CH
authors.lastname: Tsai
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania, 15213 (USA).
authors.forename: Danielle N
authors.initials: DN
authors.lastname: Chirdon
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania, 15213 (USA).
authors.forename: Husain N
authors.initials: HN
authors.lastname: Kagalwala
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania, 15213 (USA).
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Maurer
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Avenue, 308 Mellon Hall, Pittsburgh, Pennsylvania, 15282 (USA).
authors.forename: Aman
authors.initials: A
authors.lastname: Kaur
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Avenue, 308 Mellon Hall, Pittsburgh, Pennsylvania, 15282 (USA).
authors.forename: Tomislav
authors.initials: T
authors.lastname: Pintauer
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania, 15213 (USA).
authors.forename: Stefan
authors.initials: S
authors.lastname: Bernhard
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania, 15213 (USA). noonan@andrew.cmu.edu.
authors.forename: Kevin J T
authors.initials: KJ
authors.lastname: Noonan
keywords: cyanides; electrochemistry; electron relays; photocatalysis; sulfur heterocycles