Multiphonon Relaxation in Molecular Lanthanoid Luminescence

分子镧系元素发光中的多声子弛豫

• 批准号: 256010690
• 负责人: Professor Dr. Michael Seitz
• 金额: --
• 依托单位: Institut für Anorganische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/256010690?language=en
• 关键词: Multiphonon; Relaxation; Molecular; Lanthanoid; Luminescence

Non-radiative deactivation of excited levels in molecular compounds by the interaction of electronic states and vibrational overtones (= multiphonon relaxation, MR) is one of the most fundamental phenomena in the photophysics of light-emitting systems. One of the most interesting class of luminophores that are severely hampered by MR via anharmonic, high-energy oscillators are molecular lanthanoid complexes that emit in the near-infrared region of the spectrum (ca. 650-2000 nm). A detailed empirical and theoretical understanding of the intricacies determining MR in these species is still in its very infancy despite of the great technological potential of near-IR luminescence in areas like biomedical imaging or optical telecommunication. The current proposal aims at alleviating this situation by developing a comprehensive understanding of MR in molecular lanthanoid luminescence. The key enabling methodology for its realization is the organic synthesis of stereochemically well defined lanthanoid complexes which are systematically labeled with heavier isotopes (e.g. C-D instead of C-H). These tailor-made, isotopologic model systems allow the quantification of critical parameters for MR induced by typical structural motifs in the ligands. In particular, the project entails the determinations of the 3D complex structures in solution (paramagnetic 1H NMR), the non-radiative deactivation rates (time-resolved luminescence spectroscopy) and the vibrational overtone properties (near-IR absorption spectroscopy) of various coupled oscillator fragments, followed by integration of all empirical data under the known theoretical framework of the inductive-resonant mechanism of non-radiative transitions. The desired groundbreaking, unified understanding of MR for high-energy, anharmonic oscillators would go far beyond the current state-of-the-art and complement the well-known energy gap law for harmonic, low-energy oscillators in all areas of molecular photophysics.

通过电子态和振动泛音的相互作用（=多声子弛豫，MR）导致分子化合物中激发能级的非辐射失活是发光系统光物理学中最基本的现象之一。最有趣的一类发光体是在光谱近红外区域（约 650-2000 nm）发射的分子镧系元素复合物，它们通过非谐波高能振荡器严重受到 MR 的阻碍。尽管近红外发光在生物医学成像或光通信等领域具有巨大的技术潜力，但对这些物种中决定 MR 的复杂性的详细经验和理论理解仍处于起步阶段。目前的提案旨在通过全面了解分子镧系元素发光中的MR来缓解这种情况。实现这一目标的关键方法是有机合成立体化学明确的镧系元素络合物，这些络合物系统地用较重同位素标记（例如 C-D 而不是 C-H）。这些定制的同位素模型系统可以量化配体中典型结构基序诱导的 MR 关键参数。特别是，该项目需要确定溶液中的 3D 复杂结构（顺磁 1H NMR）、非辐射失活率（时间分辨发光光谱）和各种耦合振荡器片段的振动泛音特性（近红外吸收光谱），然后在已知的理论框架下整合所有经验数据。 非辐射跃迁的感应谐振机制。对高能非简谐振子的磁流变的理想的突破性、统一的理解将远远超出当前的最先进水平，并补充分子光物理所有领域中谐振低能振荡器的众所周知的能隙定律。

项目成果

Breakdown of the energy gap law in molecular lanthanoid luminescence: the smallest energy gap is not universally relevant for nonradiative deactivation.

• DOI: 10.1021/ic500017a
• 发表时间: 2014-03
• 期刊: Inorganic chemistry
• 影响因子: 4.6
• 作者: Christine Doffek;Jessica Wahsner;Elisabeth Kreidt;Michael Seitz

Deuterated Molecular Ruby with Record Luminescence Quantum Yield.

• DOI: 10.1002/anie.201711350
• 发表时间: 2018-01
• 期刊: Angewandte Chemie
• 作者: Cui Wang;Sven Otto;Matthias Dorn;Elisabeth Kreidt;Jakob Lebon;L. Sršan;Patrick Di Martino‐Fumo;M. Gerhards;U. Resch‐Genger;Michael Seitz;K. Heinze

Nonradiative Deactivation of Lanthanoid Excited States by Inner-Sphere Carboxylates.

内层羧酸盐对镧系元素激发态的非辐射失活

• DOI: 10.1021/acs.inorgchem.5b01920
• 发表时间: 2015
• 期刊: Inorganic chemistry
• 影响因子: 4.6
• 作者: J. Wahsner;M. Seitz
• 通讯作者: M. Seitz