Supporting information Table S1. Analytical and physical data of the HL ligand and its complexes

Supporting information Scheme S1. Mass fragmentation patterns of the HL ligand.

Supporting information Figure S1. Mass spectrum of [Ni(L)(H2O)]NO3.0.5CH3OH 1

Supporting information Figure S2. Mass spectrum of [Co(L)(NO3)2(H2O)] 2

Supporting information Figure S3. Mass spectrum of [Fe(L)(NO3)2(H2O)].0.5CH3OH 3

Supporting information Table S2. Distinctive IR spectral data of HL ligand and its complexes

Supporting information Scheme S2. Tautomeric forms of the HL ligand

Supporting information Table S3. Electronic spectra, magnetic moments and molar conductivity data of HL ligand and its complexes

Supporting information Figure S4. Electronic spectrum of the Ni (II) complex 1

Supporting information Figure S5. Electronic spectrum of the Co (II) complex 2

Supporting information Figure S6. Electronic spectrum of the Fe (III) complex 3

Supporting information Figure S7. 1H-NMR spectrum of Ni (II) complex 1 in (DMSO-d6)

Supporting information Figure S8. 1H-NMR spectrum of Co (III) complex 2 in (DMSO-d6)

Supporting information Figure S9. The relation between νC=O versus δ H-5chromone/ppm

Supporting information Figure S10. The relation between νC=N cm−1 versus δ HC=N/ppm

Supporting information Figure S11. 13C-NMR spectrum of HL ligand in (DMSO-d6)

Supporting information Table S5. Solvatochromic data of metal complexes

Supporting information Figure S12. The fluorescence spectra for Ni (II) 1 in different solvents

Supporting information Figure S13. The fluorescence spectra for Co (III) 2 in different solvents

Supporting information Table S6. Calculated values of solvent parameters (n, ε), microscopic solvent polarity (ETN) and solvent polarity functions (F1, F2, F3), solvents are listed in the order of increasing dielectric constants.

Supporting information Figure S14. The relation between Stock Shift/cm−1 vs F1

Supporting information Figure S15. The relation between Stock Shift/cm−1 vs Fk-c-v

Supporting information Table S7. Calculated values of solvent parameters (n, ε), microscopic solvent polarity (ETN) and solvent polarity functions (F1, F2, F3), solvents are listed in the order of increasing dielectric constants.

Supporting infrmation Table S8. Intercept (C), the slope (S), correlation coefficient (r) and number of data points (n) corresponding to statistical treatment of spectral shifts of metal complexes

Supporting information Figure S16. The relation between Stock Shift/cm−1 vs ET