5279-32-3Relevant articles and documents
Photochemistry and photophysical properties of novel, unsymmetrically substituted metallophthalocyanines
Lawrence, David S.,Whitten, David G.
, p. 923 - 935 (1996)
A series of novel, unsymmetrically substituted metallophthalocyanines was synthesized, along with their symmetrically substituted analogs, and the effects of structure and metal substitution on their photophysical and photoredox properties were investigated. The macrocycles were synthesized using a mixed-condensation method followed by chromatographic separation of the resulting soluble products. They possess a catechol 'active site' and three tert-butyl groups for enhanced solubility. The ground- and excited- state photophysical properties of the free-base, Zn(II) and Pd(II) macrocycles were measured and compared with their symmetrically substituted (tetra[tert-butyl]) analogs. The efficiency with which these macrocycles sensitize the formation of singlet oxygen was determined and discussed in the context of the excited-state photophysical properties. Several examples of photoinduced electron transfer reactions with one- and two-electron acceptors are demonstrated and discussed. These soluble molecules can be tuned to optimize their photochemical and redox properties by varying the central metal, axial ligands and other substituents, thereby providing a series of molecules for the investigation of photodynamic therapy and photoinduced electron transfer mechanisms.
Design of twisted conjugated molecular systems towards stable multi-colored electrochromic polymers
Gu, Hua,Hu, Faqi,Jian, Nannan,Lin, Kaiwen,Liu, Ximei,Lu, Baoyang,Wu, Tao,Xu, Jingkun,Xue, Yu
, (2020/08/13)
Promising advancement of conjugated polymers in electrochromic devices require to design high-performance electrochromic polymers with rich color conversion and long-term stability under cyclic electrical loads. Here we report a new strategy in developing multi-colored electrochromic polymers with good stability via twisted conjugated molecular engineering. A series of twisted hybrid precursors are synthesized by coupling ortho-alkylenedioxybenzenes with EDOT units, and their corresponding polymers are facilely electrosynthesized at relatively low polymerization potentials. The structure-property relationships of such ortho-alkylenedioxybenzene-EDOT hybrid precursors and polymers are systematically elucidated via DFT calculations, spectral, morphological, electrochemical and spectroelectrochemical analysis, etc. We demonstrate that the dihedral angle between ortho-alkylenedioxybenzenes and EDOT moieties can substantially affect the electrochemical and electrochromic properties of polymers. As the dihedral angle and electron cloud density increases, these hybrid polymers display distinct multiple color switching nature and good overall performance including high coloration efficiency (>200 cm2 C?1), decent optical contrast (>45percent), fast switching (1 s), and excellent switching stability (96percent of optical contrast after 3500 cycling) under cyclic electrical loads. With these findings, this work will provide novel insights for rational design of stable and highly efficient multi-colored electrochromic polymers.
Access to Atropisomerically En-riched Biaryls by the Coupling of Aryllithiums with Arynes under Control by Homochiral Oxazolines
Yalcouye, Boubacar,Berthelot-Bréhier, Ana?s,Augros, David,Panossian, Armen,Choppin, Sabine,Chessé, Matthieu,Colobert, Fran?oise,Leroux, Frédéric R.
supporting information, p. 725 - 732 (2017/01/18)
We report the preparation of axially stereoenriched biphenyls by the coupling of in situ generated aryllithiums and arynes using chiral oxazoline auxiliaries. The design of the aryne precursors, the choice of oxazoline and the reaction conditions were key to accessing the desired, highly substituted, atropisomerically enriched biarylic products. In one case, the two atropo-diastereomers could be obtained in isomerically pure form by column chromatographic separation and their absolute configurations established by X-ray crystallography. The stereoselectivity of the reaction seems to be governed by subtle parameters.
