Enhanced circularly polarized luminescence of chiral Eu(iii) coordination polymers with structural strain
Enhanced circularly polarized luminescence of chiral Eu(iii) coordination polymers with structural strain
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具有结构应变的手性Eu(iii)配位聚合物的增强圆偏振发光
DOI：
10.1039/d2dt03422k
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发表时间：
2023
影响因子：
4
通讯作者：
Hasegawa Yasuchika
中科院分区：
文献类型：
--
作者：
Tsurui Makoto;Kitagawa Yuichi;Shoji Sunao;Fushimi Koji;Hasegawa Yasuchika
研究了三种不同畸变手性配体的Eu（III）配位聚合物[Eu（+tfc）3（p-dpeb）]n、[Eu（+pfc）3（p-dpeb）]n和[Eu（+hfc）3（p-dpeb）]n（+tfc：（+）-3-（三氟乙酰基）戊酸盐，+PFC：（+）-3-（五氟丙酰）丙酸盐+hfc：（+）-3-（七氟丁酰基）戊酸盐，p-dpeb：1，4-二（二苯基磷酰基乙炔基）苯），以阐明它们的结构畸变，配体-金属电荷转移（LMCT），和圆偏振发光（CPL）性质。它们在配体中的应变因子进行了评估，使用单晶X-射线结构分析获得的晶体学数据。从理论计算中估计了LMCT激发态的特性。在手性配体中引入大体积取代基后，β-二酮的结构发生了畸变，并改变了跃迁电偶极矩的方向，这与CPL强度的大小有关。具有大畸变结构的[Eu（+hfc）3（p-dpeb）]n的CPL不对称因子（gCPL）为−0.22，而具有小畸变结构的[Eu（+tfc）3（p-dpeb）]n和[Eu（+pfc）3（p-dpeb）]n的CPL不对称因子（gCPL）分别为−0.05和−0.10。Eu（III）配位聚合物中手性配体的可控空间位阻是提高其CPL性能的应变因素之一。
Three types of Eu(III) coordination polymers with different distorted chiral ligands, [Eu(+tfc)3(p-dpeb)]n, [Eu(+pfc)3(p-dpeb)]n, and [Eu(+hfc)3(p-dpeb)]n (+tfc: (+)-3-(trifluoroacetyl)camphorate, +pfc: (+)-3-(pentafluoropropionyl)camphorate, +hfc: (+)-3-(heptafluorobutyryl)camphorate, p-dpeb: 1,4-bis(diphenylphosphorylethynyl)benzene), were prepared for elucidating the relationship between their structural distortions, ligand-to-metal charge transfer (LMCT), and circularly polarized luminescence (CPL) properties. Their strain factors in the ligands were evaluated using crystallographic data obtained by single-crystal X-ray structural analyses. The characteristics of the LMCT excited states were estimated from theoretical calculations. The introduction of a bulky substituent into the chiral ligand afforded a distorted structure of β-diketonates and changed the direction of the transition electric dipole moments, which are related to the magnitude of the CPL intensity. The CPL dissymmetry factor (gCPL) of [Eu(+hfc)3(p-dpeb)]n, with a large distorted structure, was −0.22, while those of [Eu(+tfc)3(p-dpeb)]n and [Eu(+pfc)3(p-dpeb)]n, with small distorted structures, were −0.05 and −0.10, respectively. The controlled steric hindrance of the chiral ligands in Eu(III) coordination polymers is one of the strain factors enhancing their CPL properties.