25796-72-9Relevant academic research and scientific papers
Rethinking Uncaging: A New Antiaromatic Photocage Driven by a Gain of Resonance Energy
Hermanns, Volker,Scheurer, Maximilian,Kersten, Nils Frederik,Abdellaoui, Chahinez,Wachtveitl, Josef,Dreuw, Andreas,Heckel, Alexander
, p. 14121 - 14127 (2021/09/03)
Photoactivatable compounds for example photoswitches or photolabile protecting groups (PPGs, photocages) for spatiotemporal light control, play a crucial role in different areas of research. For each application, parameters such as the absorption spectrum, solubility in the respective media and/or photochemical quantum yields for several competing processes need to be optimized. The design of new photochemical tools therefore remains an important task. In this study, we exploited the concept of excited-state-aromaticity, first described by N. Colin Baird in 1971, to investigate a new class of photocages, based on cyclic, ground-state-antiaromatic systems. Several thio- and nitrogen-functionalized compounds were synthesized, photochemically characterized and further optimized, supported by quantum chemical calculations. After choosing the optimal scaffold, which shows an excellent uncaging quantum yield of 28 %, we achieved a bathochromic shift of over 100 nm, resulting in a robust, well accessible, visible light absorbing, compact new photocage with a clean photoreaction and a high quantum product (??Φ) of 893 M?1 cm?1 at 405 nm.
The effect of heteroatom conformation on optoelectronic properties of cyclopentadithiophene derivatives
Wanwong, Sompit,Poe, Ambata,Balaji, Ganapathy,Thayumanavan
, p. 2474 - 2478 (2014/04/03)
Cyclopentadithiophene (CPDT) derivatives with different heteroatom conformations have been synthesized. The optical, electrochemical and charge transport properties of these molecules are reported. The CPDT-anti-ketone not only exhibits the lowest optical and electronic bandgaps, but also exhibits reasonable hole mobility, 3 × 10-3 cm2 (V s) -1. Changing the carbonyl conformation to the syn position or incorporating the imine functionality results in a blue-shift in the lower energy band of the absorption spectrum indicative of the increased bandgaps. the Partner Organisations 2014.
New syntheses of tricyclic thiophenes and cyclic tetrathiophenes using transition-metal-catalyzed cyclization
Kabir, S. M. Humayun,Miura, Mami,Sasaki, Shigeru,Harada, Genta,Kuwatani, Yoshiyuki,Yoshida, Masato,Iyoda, Masahiko
, p. 761 - 774 (2007/10/03)
New synthetic methods for polycyclic thiophenes were developed. Thus, dithienothiophenes, cyclopentadithiophene, silacyclopentadithiophenes, and cyclooctatetrathiophenes were synthesized in moderate to good yields by using the CuCl2-mediated cyclization of organocopper(I) and organozinc intermediates prepared from dilithio-derivatives with CuCN or ZnCl2, respectively. A direct cyclization of bromothiophene derivatives with hexamethylditin in the presence of tetrakis(triphenylphosphine)palladium(0) also gave dithienothiophenes, cyclopenta-dithiophenes, and silacyclopentadithiophenes in good yields.
