Ru(0)-catalysed cross-dimerisation and -trimeisation of alkynyl with butadienylheteroarenes
Ru(0)-catalysed cross-dimerisation and -trimeisation of alkynyl with butadienylheteroarenes
复制标题
Ru(0)催化的炔基与丁二烯基杂芳烃的交叉二聚和三聚化
DOI：
10.1039/d3ob00207a
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Nobuyuki Komine and Masafumi Hirano
中科院分区：
文献类型：
--
作者：
Sayori Kiyota;Kohei Kamakura;Nobuyuki Komine and Masafumi Hirano
Ru(0)催化的交叉二聚和三聚反应得到一系列由π共轭的三烯基团交联的二芳基和三杂芳基化合物。用紫外-可见吸收光谱、荧光发射光谱和TD-DFT计算研究了它们的光化学行为。以2，5-二烷基噻吩为原料，与2当量反应制得了交叉三聚体。2-丁二烯基吡啶与1-苯基丁二烯制备的交叉三聚体相比，其最大吸收峰有较长的波长漂移。溶剂效应和密度泛函理论计算表明，π共轭体系的平面性比自发极化的贡献更大。也就是说，在5元噻吩环中，共轭的三烯基与噻吩基在同一平面上延伸(二面角：-4.0°)，而在6元苯环中，由于空间位阻(二面角：-24.1°)，平面度降低。因此，由于共轭三烯基团的平面性增加，具有5元杂芳基中心的交叉三聚体有助于更长波长的吸收和荧光发射。
Ru(0)-catalysed cross-dimerisation and -trimerisation give a series of di- and triheteroaryl compounds cross-linked by π-conjugated trienyl groups. Their photochemical behaviour is studied using UV-visible absorption spectra, fluorescence emission spectra, and TD-DFT calculations. The cross-trimer prepared from 2,5-dialkynylthiophene with 2 equiv. of 2-butadienylpyridine shows a longer wavelength shift in the absorption maximum than the cross-trimer prepared from dialkynylbenzene with 1-phenylbutadiene. The solvent effect and the TD-DFT calculations suggest that the planarity of the π-conjugated system contributes more than spontaneous polarization. Namely, in the 5-membered thiophene ring, the conjugated trienyl group extends in the same plane (dihedral angle: –4.0°) as the thienyl group, whereas in the 6-membered benzene ring, the planarity is reduced due to steric hindrance (dihedral angle: –24.1°). Thus, the cross-trimers with a 5-membered heteroaryl centre contribute to longer wavelengths of absorption and fluorescence emission due to the increased planarity of the conjugated trienyl groups.