The solvatochromic behavior and degree of ionicity of a synthesized pentacyano (N-substituted-4,4′-bipyridinium) ferrate(II) complex in different media. Tuning the solvatochromic intensity in aqueous glucose solutions

- A solvatochromic pentacyanoferrate(II) complex was synthesized and characterized.
- Its solvatochromic behavior was studied in neat solvents and their binary mixtures.
- The behavior of the complex is altered in aqueous glucose solutions.
- The impact of specific and non-specific solute-solvent interactions was investigated.
- A tunable solvatochromic behavior of weak intensity was revealed in aqueous glucose.

A new solvatochromic pentacyanoferrate(II) complex with a 4,4′-bipyridine based dicationic ligand was synthesized and characterized. Its chromotropic behavior markedly affected by solvent polarity was examined in different media i.e. neat solvents, binary solvent mixtures, and aqueous glucose solutions, and quantified using suitable solvent polarity parameters. The metal to ligand charge transfer (MLCT) energy shows a linear correlation with the Reichardt solvent polarity parameter as well as the Kirkwood dipolarity function and suitable functions expressing polarizability. Using suitable Linear Solvation Energy Relationships (LSERs) it was concluded that mainly specific solute-solvent interactions contribute to the solvatochromic phenomenon. The investigation of the solvatochromic behavior of the title compound in aqueous glucose solutions revealed a different response to medium polarity. Tuning of the solvatochromic intensity of the title compound by changing the type of medium was further studied focusing on aqueous glucose solutions.