The formation of peroxide degradation products of photochromic triphenylimidazolyl radical-dimers.
The formation of peroxide degradation products of photochromic triphenylimidazolyl radical-dimers.
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DOI：
10.1039/c3cp50757b
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发表时间：
2013-05
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影响因子：
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通讯作者：
Robert M. Edkins;M. Probert;K. Fucke;C. Robertson;J. Howard;A. Beeby
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作者：
Robert M. Edkins;M. Probert;K. Fucke;C. Robertson;J. Howard;A. Beeby
根据Abe及其同事最近的报告（Phys. Chem. Chem. Phys.，2012，14，5855）中，本文报道了这种降解途径是2，4，5-三苯基咪唑基自由基（TPIR）材料的铬二聚体的更普遍的现象，其中非束缚的TPIR形成类似的氧加合物。两种衍生物的过氧化物已通过单晶X-射线衍射（SC-XRD）表征，并确定咪唑环的4-位是易与氧反应的位点。此外，质谱法已被用来表明，对于一系列的五个已知的，非栓系衍生物，过氧化物的形成可以检测到在30分钟内，当样品在氧气气氛下照射，从而提出了一个显着的挑战，长期使用这类材料的颜色切换设备的应用。
Following the recent report of Abe and co-workers (Phys. Chem. Chem. Phys., 2012, 14, 5855) of the isolation of a bridging peroxide of a naphthalene-tethered bisimidazolyl diradical, it is reported herein that this degradation pathway is a more general phenomenon for the chromic dimers of 2,4,5-triphenylimidazolyl radical (TPIR) materials, with non-tethered TPIRs forming similar oxygen adducts. The peroxides of two derivatives have been characterised by single crystal X-ray diffraction (SC-XRD) and it is identified that the 4-position of the imidazolyl ring is the site susceptible to reaction with oxygen. Furthermore, mass spectrometry has been used to show that for a range of five known, non-tethered derivatives, peroxide formation can be detected within 30 minutes when samples are irradiated under an oxygen atmosphere, thus presenting a significant challenge to the long term use of this class of material in colour-switching device applications.