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首页> 外文期刊>Chemistry: A European journal >Oligotriarylamines with a Pyrene Core: A Multicenter Strategy for Enhancing Radical Cation and Dication Stability and Tuning Spin Distribution
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Oligotriarylamines with a Pyrene Core: A Multicenter Strategy for Enhancing Radical Cation and Dication Stability and Tuning Spin Distribution

机译：具有igo核的寡三芳基胺：增强自由基阳离子和阳离子稳定性和调节自旋分布的多中心策略

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摘要

Monoamine 1, diamines 2-4, triamine 5, and tetraamine 6 have been synthesized by substituting dianisylamino groups at the 1-, 3-, 6-, and/or 8-positions of pyrene. Diamines 2-4 differ in the positions of the amine substituents. No pyrene-pyrene interactions are evident in the single-crystal packing of 3, 4, and 6. With increasing numbers of amine substituents, the first oxidation potential decreases progressively from the mono-to the tetraamine. These compounds show intense charge-transfer (CT) emission in CH2Cl2 at around 530 nm with quantum yields of 48-68 %. Upon step-wise oxidation by electrolysis or chemical oxidation, these compounds were transformed into radical cations 1(+)-6(+) and dications 2(2+)-6(2+), which feature strong visible and near-infrared absorptions. Time-dependent density functional theory studies suggested the presence of localized transitions from the pyrene radical cation and aminium radical cation, intervalence CT, and CT between the pyrene and amine moieties. Spectroscopic studies indicated that these radical cations and dications have good stability. Triamine 5 and tetraamine 6 formed efficient CT complexes with tetracyanoquinodimethane in solution. The results of EPR spectroscopy and density functional theory calculations suggested that the dications 2(2+)-4(2+) have a triplet ground state, whereas 5(2+) and 6(2+) have a singlet ground state. The dication of 1,3-disubstituted diamine 4 exhibits a strong EPR signal.
机译：单胺1，二胺2-4，三胺5和四胺6已经通过在dian的1-，3-，6-和/或8-位取代二苯胺基氨基而合成。二胺2-4的胺取代基的位置不同。在3、4和6的单晶堆积中没有pyr- pyr相互作用。随着胺取代基数量的增加，第一氧化电位从单胺到四胺逐渐降低。这些化合物在CH2Cl2中约530 nm处显示出强烈的电荷转移（CT）发射，量子产率为48-68％。通过电解或化学氧化逐步氧化后，这些化合物被转化为自由基阳离子1（+）-6（+）和阳离子2（2 +）-6（2+），具有较强的可见光和近红外吸收特性。随时间变化的密度泛函理论研究表明，from和胺基团之间存在from离子和a离子的局部跃迁，间隔CT和CT。光谱研究表明这些自由基阳离子和阳离子具有良好的稳定性。三胺5和四胺6与四氰基喹二甲烷在溶液中形成有效的CT络合物。 EPR光谱和密度泛函理论计算的结果表明，指示2（2 +）-4（2+）具有三重态基态，而5（2+）和6（2+）具有单重态基态。 1,3-二取代的二胺4的显示出很强的EPR信号。

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