Computational design of zinc-ion-responsive two-photon fluorescent probes with conjugated multi-structures

• Published in: Journal of molecular modeling 2016, Vol.22 (1), p.34-34, Article 34
• Main Authors: Huang, Shuang, Yang, Bao-Zhu, Jiang, Xing-Fang, Ren, Ai-Min
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Molecular Medicine; Original Paper; Theoretical and Computational Chemistry
• ISSN: 1610-2940; 0948-5023
• DOI: 10.1007/s00894-015-2887-7

A series of conjugated multi-structured fluorescent probe molecules based on a salen ligand were designed and investigated in dimethyl sulfoxide solvent using a quantum-chemical method. The results indicate that the one-photon absorption and fluorescence emission spectra ( λ O and λ EM ) of these molecules generally show redshifts (of 23.1–74.5 and 22.7–116.6 nm, respectively) upon the coordination of the molecules to Zn 2+ . Large Stokes shifts (1511.2–11744.1 cm −1 ) were found for the molecules, meaning that interference between λ O and λ EM can be avoided for these molecules. The two-photon absorption spectra of the molecules usually present blueshifts, but the two-photon absorption cross-section ( δ ) greatly increases (by 221.5–868.0 GM) upon the coordination of the molecules with Zn 2+ . Most of the molecules show strong two-photon absorption peaks in the range 678.2–824.4 nm, i.e., in the near-infrared region. In a word, the expanded π-conjugated frameworks of these molecules lead to redshifted λ O and λ EM and enhanced δ values. Moreover, (L-phenyl)​ 2 and (L-phenyl-ethynyl) 2 are the most suitable of the multi-structured molecules examined in this work for use as two-photon fluorescent probes for zinc ion detection in vivo. Graphical Abstract Scheme of the calculated transition energies (E 0k and E 0n ) and the transition dipole moments (M 0k and M kn ). NTO 109, NTO 197 and NTO 228 of Zn(L-phenyl-ethynyl), Zn 2 (L-phenyl-ethynyl) 2 and Zn 3 (L-phenyl) 3 for one-photon  absorption, respectively.