Theoretical Study on Spectrum and Luminescence Mechanism of Cy5.5 and Cy7.5 Dye Based on Density Functional Theory (DFT)

Zhao Liu; Xv Meng; Zhengze Zhang; Runzhang Liu; Shutao Wang; Jun-Qiang Lei

doi:10.1007/s10895-023-03525-4

Theoretical Study on Spectrum and Luminescence Mechanism of Cy5.5 and Cy7.5 Dye Based on Density Functional Theory (DFT)

J Fluoresc. 2023 Dec 5. doi: 10.1007/s10895-023-03525-4. Online ahead of print.

Authors

Zhao Liu^#¹, Xv Meng^#¹, Zhengze Zhang², Runzhang Liu¹, Shutao Wang³, Jun-Qiang Lei⁴

Affiliations

¹ First Hospital of Lanzhou University, Lanzhou University, 222 South Tianshui Road, Lanzhou, 730000, P. R. China.
² Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
³ College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou, 730000, P. R. China.
⁴ First Hospital of Lanzhou University, Lanzhou University, 222 South Tianshui Road, Lanzhou, 730000, P. R. China. leijq2011@126.com.

^# Contributed equally.

PMID: 38051402
DOI: 10.1007/s10895-023-03525-4

Abstract

Cy5.5 and 7.5 are the most commonly used NIR 2-region fluoresceins, which have good luminescence properties and important biomedical tracer applications. In this paper, their molecular non-covalent interactions, UV-Vis absorption spectra, main bond lengths, electrostatic potential distributions, frontier molecular orbitals (HOMO and LUMO) and energy gaps were calculated by density functional theory (DFT). We found that the differences in the luminescence properties and energy gaps of Cy5.5 and Cy7.5 molecules may be caused by the length of the conjugated chains between the two aromatic rings in the molecule. By calculating the relevant molecular characteristics, this paper can provide ideas and theoretical basis for the relevant modification and application, as well as the development of new fluorescent dyes.

Keywords: Cy5.5 and Cy7.5; Density Functional Theory (DFT); Pre-design of Fluorescent dye; Theoretical Spectral Calculation.

Abstract

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