Crystallography, Charge Transfer, and Two-Photon Absorption Relations in Molecular Cocrystals for Two-Photon Excited Fluorescence Imaging.

Small

Key Laboratory of Organic Integrated Circuits, Ministry of Education, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin, 300072, China.

Published: April 2024

Two-photon excited fluorescence imaging requires high-performance two-photon absorption (TPA) active materials, which are commonly intramolecular charge transfer systems prepared by traditional chemical synthesis. However, this typically needs harsh conditions and new methods are becoming crucial. In this work, based on a collaborative intermolecular charge transfer (inter-CT) strategy, three centimeter-sized organic TPA cocrystals are successfully obtained. All three cocrystals exhibit a mixed stacking arrangement, which can effectively generate inter-CT between the donor and acceptor. The ground and excited state characterizations compare their inter-CT ability: 1,2-BTC > 2D-BTC > 1D-BTC. Transient absorption spectroscopy detects TCNB, indicating that the TPA mechanism arises from molecular polarization caused by inter-CT. Meanwhile, 1,2-BTC exhibits the highest excited-state absorption and the longest excited-state lifetime, suggesting a stronger TPA response. First-principles calculations also confirm the presence of inter-CT interactions, and the significant parameter Δµ which can assess the TPA capability indicates that inter-CT enhances the TPA response. Besides, cocrystals also demonstrate excellent water solubility and two-photon excited fluorescence imaging capabilities. This research not only provides an effective method for synthesizing TPA crystal materials and elucidates the connection between inter-CT ability and TPA property but also successfully applies them in the fields of multi-photon fluorescence bioimaging.

Download full-text PDF

Source
http://dx.doi.org/10.1002/smll.202308470DOI Listing

Publication Analysis

Top Keywords

charge transfer
12
two-photon excited
12
excited fluorescence
12
fluorescence imaging
12
two-photon absorption
8
tpa
8
inter-ct ability
8
tpa response
8
inter-ct
7
two-photon
5

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!