Molecular structure, magnetic and optical properties of endometallonitridofullerene Sc3N@Ih-C80 in neutral, radical anion and dimeric anionic forms.
Molecular structure, magnetic and optical properties of endometallonitridofullerene Sc3N@Ih-C80 in neutral, radical anion and dimeric anionic forms.
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DOI：
10.1002/chem.201902782
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发表时间：
2019-11
期刊：
影响因子：
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通讯作者：
D. Konarev;A. Popov;L. Zorina;S. Khasanov;R. Lyubovskaya
中科院分区：
文献类型：
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作者：
D. Konarev;A. Popov;L. Zorina;S. Khasanov;R. Lyubovskaya
以晶体形式获得了一系列具有中性、单体和二聚阴离子状态的Sc 3 N @Ih-C80的化合物，从而可以研究它们的分子结构、光学和磁性。中性的Sc_3 N @ Ih-C_80. 3C_6H_4Cl_2（1）和（Sc_3 N @ Ih-C_80）_3（TPC）_2.5C_6H_4Cl_2（2，TPC为三蝶烯）化合物均为高对称性的三角晶系结构。Sc 3 N @Ih-C80还原为自由基阴离子导致它们的二聚化形成抗磁性单键（Sc 3 N @Ih-C80（-））2二聚体。我们合成了新的二聚体相，其中只发现一个主要的占据二聚体取向。通过EPR技术研究了二聚体的热稳定性，表明它们在400-460 K范围内解离，产生单体Sc 3 N @Ih-C80（.-）自由基阴离子。该信号显示出由于与钪原子的自旋的hfi而具有5.8mT的平均分离的超精细分裂。笼间C-C键的能量估计为234 ± 7 kJ/mol，是带负电荷的富勒烯二聚体中的最高值。结晶（Bu 3 MeP+）3（Sc 3 N @Ih-C80（.-））的EPR谱3.C_6H_4Cl_2（6）。在180 K以上，由于三个钪原子自旋的hfi效应，出现了超精细分裂（220 K时共观察到22条谱线，平均分裂为5.32mT）。除此之外，22条线中的每条线还被分成平均间隔为0.82 mT的6条线。大的分裂表明从富勒烯笼到Sc 3 N @Ih-C80（.-）内的Sc 3 N簇的基本电荷和自旋密度转移。
Series of compounds with Sc3N@Ih-C80 in neutral, monomeric and dimeric anion states was obtained in a crystalline form allowing one to study their molecular structure, optical and magnetic properties. Neutral Sc3N@Ih-C80.3C6H4Cl2 (1) and (Sc3N@Ih-C80)3(TPC)2.5C6H4Cl2 (2, TPC is triptycene) compounds are crystallized in high-symmetry trigonal structure. Reduction of Sc3N@Ih-C80 to the radical anions results in their dimerization forming diamagnetic singly-bonded (Sc3N@Ih-C80(-))2 dimers. We synthesized new dimeric phases in which only one major occupied dimer orientation was found. Thermal stability of the dimers was studied by EPR technique to show their dissociation in the 400-460 K range producing monomeric Sc3N@Ih-C80(.-) radical anions. This signal showed hyperfine splitting with average separation of 5.8 mT due to hfi of spin with scandium atoms. The energy of intercage C-C bond was estimated to be 234 ± 7 kJ/mol, the highest value among negatively charged fullerene dimers. EPR spectra of crystalline (Bu3MeP+)3(Sc3N@Ih-C80(.-))3.C6H4Cl2 (6) were presented. Hyperfine splitting is manifested above 180 K due to hfi of spin with three scandium atoms (totally 22 lines with average splitting of 5.32 mT are observed at 220 K). Besides this each of 22 lines is additionally split into six lines with average 0.82 mT separation. Large splitting indicates essential charge and spin density transfer from the fullerene cage to the Sc3N cluster inside Sc3N@Ih-C80(.-).