title: Computational design of two-photon fluorescent probes for a zinc ion based on a Salen ligand.
abstract: A two-photon fluorescent probe has become a critical tool in biology and medicine owing to its capability of imaging intact tissue for a long period of time, such as in two-photon fluorescence microscopy (TPM). In this context, a series of Salen-based zinc-ion bioimaging reagents that were designed based on an intramolecular charge-transfer mechanism were studied through the quantum-chemical method. The increase of one-photon absorption and fluorescence emission wavelength and the reduction of the oscillator strength upon coordination with a zinc ion reveal that they are fluorescent bioimaging reagents used for ratiometric detection. When the Salen ligand is incorporated with Zn(2+), the value of the two-photon absorption (TPA) cross-section (δmax) will decrease, and most of the ligands and complexes exhibit a TPA peak in the near-infrared spectral region. That is, a substituent at the end of the ligand can influence the luminescence property, besides increasing solubility. In addition, the effect of an end-substituted position on the TPA property was considered, such as ortho and meta substitution. The detailed investigations will provide a theoretical basis to synthesize zinc-ion-responsive two-photon fluorescent bioimaging reagents as powerful tools for TPM and biological detection in vivo.
authors: State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China.
authors: Shuang
authors: S
authors: Huang
authors: Lu-Yi
authors: LY
authors: Zou
authors: Ai-Min
authors: AM
authors: Ren
authors: Jing-Fu
authors: JF
authors: Guo
authors: Xiao-Ting
authors: XT
authors: Liu
authors: Ji-Kang
authors: JK
authors: Feng
authors: Bao-Zhu
authors: BZ
authors: Yang
mesh_terms: D005029:Ethylenediamines / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008024:Ligands; D008856:Microscopy, Fluorescence; D017785:Photons; D011789:Quantum Theory; D015032:Zinc / Q000737:chemistry*
chemical_list: D005029:Ethylenediamines; D005456:Fluorescent Dyes; D007477:Ions; D008024:Ligands; C011452:disalicylaldehyde ethylenediamine; D015032:Zinc