Synthesis, characterisation and quantum chemical studies of a new series of iron chelatable fluorescent sensors

ABSTRACT

A series of iron chelatable fluorescent probes based on 3-hydroxypyridin-4-ones or 3-hydroxypyran-4-ones have been designed and synthesised. The fluorescence of the probes are sensitive to the presence of Fe³⁺ with a metal-to-ligand ratio of 1:3. Fluorescence quenching of hydroxypyranone-based probes was found to be inferior to that of hydroxypyridones. Based on density functional theory calculations at the B3YP/6–31G+(d,p) level of theory, geometry optimisations of ligands and ligand-Fe³⁺ complex were obtained. Quantum mechanical calculations were also carried out with the Gaussian 09W program to obtain the properties of these molecules, such as binding energy (E_bind), HOMO–LUMO energy gap (ΔE_gap), hardness (η), softness (S), electronegativity (χ), chemical potential (μ), electrophilicity (ω) and nucleophilicity (ϵ), which have significant influence for pFe³⁺ because of high correlation coefficients.

GRAPHICAL ABSTRACT

KEYWORDS:

• 3-Hydroxypyridin-4-one
• fluorescent probe
• iron chelator
• density functional theory calculations
• binding energy

Disclosure statement

The authors declare no competing financial interest.

Additional information

Funding

Financial support from Zhejiang Provincial Natural Science Foundation of China [LY17H300005] is gratefully acknowledged.