A Modular Approach for the Synthesis of Nanometer-Sized Polynitroxide Multi-Spin Systems

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• 作者：Silvia Valera ; James E. Taylor ; David S. B. Daniels ; Daniel M. Dawson ; Kasun S. Athukorala Arachchige ; Sharon E. Ashbrook ; Alexandra M. Z. Slawin ; Bela E. Bode
• 刊名：Journal of Organic Chemistry
• 出版年：2014
• 出版时间：September 5, 2014
• 年：2014
• 卷：79
• 期：17
• 页码：8313-8323
• 全文大小：563K
• ISSN：1520-6904

文摘

The synthesis of rigid symmetric polyradical model systems with inter-spin distances between 1.4 and 4 nm and their room temperature continuous wave (CW) EPR spectra are reported. Conditions for attachment of the spin-label via esterification have been optimized on the direct synthesis of polyradicals from commercially available polyphenols and the carboxylic acid functionalized nitroxide TPC. A common synthetic protocol utilizing 4-hydroxy-4鈥?iodobiphenyl as a key building block has been used to synthesize an equilateral biradical and a triradical in only two steps from commercially available starting materials. The first synthesis of a tetraradical based upon an adamantane core bearing six equivalent nitroxide鈥搉itroxide distances is also reported. These systems are very promising candidates for studying multi-spin effects in pulsed EPR distance measurements.