Synthesis and properties of star-like nitroxide radicals

Journal Information

J. Hefei Univ. Tech. (Nat. Sci.), Apr.2026, Vol.49 No.4: 516-522

DOI: 10.3969/j.issn.1003-5060.2026.04.012

Authors

YU Huabing $ ^{1} $, WANG Wenping $ ^{1} $, WANG Di $ ^{2} $, SHI Chengfang $ ^{1} $, HUANG Zhulin $ ^{3} $

(1. School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China; 2. School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China; 3. Sinopec Anqing Petrochemical Company, Anqing 246002, China)

Abstract and Keywords

Abstract: In this paper, the required star-like nitroxide radicals were synthesized from 1,3,5-tribromobenzene, bis(pinacolato)diboron, p-bromobenzaldehyde, and 2,3-dimethyl-2,3-di(hydroxylamine)-butane by Miyaura reaction, Suzuki coupling reaction, aldimine condensation reaction and oxidation reaction. The structure and properties of the synthesized radicals were characterized by ultraviolet-visible spectrophotometer (UV-Vis), electron spin resonance spectroscopy (ESR) and vibration magnetometer. UV-Vis measurements show that the $ \pi-\pi^{} $ and $ n-\pi^{} $ absorption peaks of the radicals are offset in the range of 500-700 nm in toluene, dichloromethane and acetonitrile solvents, and the optical band gaps are deduced to be 2.68 eV, 2.54 eV, and 2.45 eV. The EPR analysis shows that the decrease of temperature will lead to the splitting of the characteristic peaks of radicals, the increase of width and the decrease of number; when the temperature is 210 K, the distance between dipoles (r) of 1.19 nm is derived from electron spin resonance spectrum of allowed transitions of radicals. The vibration magnetometer measurements show that the critical temperature ( $ T_{c} $) of the synthesized nitroxide radicals is 15 K, which is higher than that of the early nitroxide radicals.

Keywords: Miyaura reaction; Suzuki coupling reaction; aldimine condensation reaction; nitroxide radicals; critical temperature

作者信息

余华兵 $ ^{1} $，王文平 $ ^{1} $，王帝 $ ^{2} $，史诚芳 $ ^{1} $，黄竹林 $ ^{3} $

（1. 合肥工业大学化学与化工学院，安徽合肥 230009；2. 安徽建筑大学材料与化学工程学院，安徽合肥 230601；3. 中国石化安庆石化公司，安徽安庆 246002）

摘要和关键词

摘要: 文章以1,3,5-三溴苯、频哪醇二硼、对溴苯甲醛、2,3-二甲基-2,3-二（羟胺）-丁烷为原料，经过Miyaura反应、Suzuki偶联反应、醛胺缩合反应和氧化反应合成所需星状结构氮氧自由基化合物。合成的自由基化合物分别用紫外-可见分光光度计、电子自旋共振波谱仪（electron spin resonance spectroscopy，ESR）和振动磁强计进行结构表征和性能测试。在甲苯、二氯甲烷、乙腈溶剂中的紫外测试结果表明，自由基化合物 $ \pi\pi^{} $和 $ n\pi^{} $吸收峰在500~700 nm范围内会有所偏移，并推导出间带光学能隙为2.68、2.54、2.45 eV。ESR表征结果表明：温度降低会导致自由基化合物特征峰的分裂、宽度增大和数量减少；温度为210 K时，通过自由基发生允许跃迁的电子自旋谱图推导出偶极间距离r=1.19 nm。通过振动磁强计测得合成的氮氧自由基化合物临界温度 $ T_{c} $为15 K，相较于早期的氮氧自由基化合物有更高的临界温度。

关键词: Miyaura 反应；Suzuki 偶联反应；醛胺缩合反应；氮氧自由基；临界温度

Funding

国家自然科学基金青年科学基金资助项目（52003004）

合肥工业大学学报(自然科学版)

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