| 含硼中性自由基二聚体 | |
| Neutral boron-containing radical dimers | |
| 摘要: 双酮化合物与等物质的量的碳化钾(KC8)和二(五氟苯基)氯硼烷一锅法直接合成了一系列含硼中性自由基二聚体1~3。利用核磁共振和单晶X射线衍射表征了该系列化合物的结构。晶体结构解析表明，3种化合物均为三斜晶系 $P \overline{1}$ 空间群。1的晶胞参数为a=0.914 93(3) nm，b=1.292 24(4) nm，c=1.526 46(6) nm，α=108.715(2)°，β=103.002(2)°，γ=102.557(2)°；2的晶胞参数为a=1.197 14(5) nm，b=1.352 20(6) nm，c=1.352 20(6) nm，α=96.108 0(10)°，β=105.189(2)°，γ=102.557(2)°；3的晶胞参数为a=1.190 50(15) nm，b=1.362 4(2) nm，c=1.848 3(3) nm，α=77.376(6)°，β=79.817(5)°，γ=102.557(2)°。3种化合物均形成了四配位的硼中心，且其分子骨架分别以“头碰头”和“肩并肩”的形式发生σ二聚。结合密度泛函理论计算研究了其二聚键长的变化规律和可能的反应机理，晶体数据和理论计算数据显示，分子的二聚键长受骨架的共轭程度和二聚碳取代基的空间位阻效应协同影响。测试了3种分子的紫外可见吸收光谱和荧光发光性质，结果发现三者均在414 nm附近出现明显的吸收峰。荧光测试显示，二聚体2在480 nm处有发光峰，且荧光发射峰随溶液浓度增加发生轻微红移。 | |
| 关键词: 含硼自由基 二聚体 四配位硼中心 | |
| 基金项目: 国家自然科学基金(No.22231005)和中国科学院战略重点研究计划(No.XDB0610000)资助。 | |
| Abstract: A series of neutral boron-containing radical dimers were prepared directly from diketone compounds with KC8 and BCl(C6F5)2 through one pot method under an inert atmosphere. The 1H NMR signal shows the formation of sp3-hybrid carbon atoms while the single crystal X-ray diffraction data demonstrate σ-dimerization structures. A tetra-coordinated boron center was formed on each diketon skeleton. Three compounds crystallize in triclinic space system, space group $P \overline{1}$ with a=0.914 93(3) nm, b=1.292 24(4) nm, c=1.526 46(6) nm for 1, a=1.197 14(5) nm, b= 1.352 20(6) nm, c=1.352 20(6) nm for 2, and a=1.190 50(15) nm, b=1.362 4(2) nm, c=1.848 3(3) nm for 3. The dimerization mechanism was investigated by density functional theory calculation, revealing the effects between steric hindrance, electron effects, and dimerization carbon-carbon length. Three compounds have a similar UV-Vis absorption peak at 414 nm. Dimer 2 has fluorescence luminescence property at 480 nm and the wavelength redshift slightly with increasing concentration. | |
| Keywords: boron-containing radical dimer tetra-coordinated boron center | |
| 投稿时间：2024-10-10 修订日期：2024-11-25 | |
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| 刘敏,阮华棚,冯钟涛,董学,崔海燕,王新平.含硼中性自由基二聚体[J].无机化学学报,2025,41(1):123-130. | |
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