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oe1(光电查) - 科学论文

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  • Fine-Tuning Aromatic Stacking and Single-Crystal Photoluminescence through Coordination Chemistry

    摘要： Organic aromatics usually show a decrease in fluorescence efficiency in the solid state on account of well-known aggregation induced quenching. We have found that single crystals of coordination polymers consisting of γ-aminobutyric acid functionalized naphthalenediimide ligand (H2GABA-NDI) can give rise to highly emissive, broad, and red-shifted photoluminescence (PL) in the solid state. To better understand the origin of the bandwidth broadening with the π–π stacking distances, we performed time-resolved PL studies in a series of polymers with a variety of metal centers. We conclude that the broad steady-state PL signals is originated from a superposition of two emissive states with differing energy and lifetimes, with the lower energy one produced by the interchromophoric interactions mediated by π–π stacking of neighboring NDI units. Our work demonstrates that coordination chemistry is an effective tool to modulate interchromophoric couplings and that simple PL analysis can be used as a measure of the degree of π-stacking.

    关键词： crystal engineering,luminescence,photochemistry,stacking interactions,coordination modes

    更新于2025-09-23 15:22:29

  • Effect of Coordination Modes on the Tunable Luminescence of 1,10-Phenanthroline-Based Complexes

    摘要： Two luminescent compounds [Zn(L)2](ClO4)2 (1) and [Na(L)(MeOH)(μ-ClO4)]n (2) are obtained from the reactions of 2,9-bis(carbomethoxy)-1,10-phenanthroline (L) with corresponding hydrated perchlorate salts in MeOH. Their crystal structures are determined by X-ray crystallography. 1 is a mononuclear 8-coordinate Zn2+ compound and 2 is a ?-bridged 1D polymer, where the ligand L exhibits di?erent coordination modes (carbonyl O vs methoxyl O coordination). Although the luminescence of these two compounds originates similarly from the ligand-centered π→π* transitions, it is interesting to note that their emissions are signi?cantly in?uenced by the di?erent coordination modes of L. The relationship between their structures and emission properties has been investigated in detail. The stability and energy di?erence between these two coordination modes in these two compounds are analyzed by Time-dependent density functional theory (TD-DFT) calculations.

    关键词： sensor,luminescence,2,9-bis(carbomethoxy)-1,10-phenanthroline,different coordination modes

    更新于2025-09-09 09:28:46