Akademik Veri Yönetim Sistemi
Inorganica Chimica Acta, cilt.592, 2026 (SCI-Expanded, Scopus)
Although the field of inorganic photophysics and photochemistry has traditionally been dominated by complexes of precious and rare metals, increasing concerns regarding their scarcity and cost have led to a growing interest in earth-abundant metal-based compounds as more sustainable and economically viable alternatives. In this study, we investigated the photophysical properties of two water-soluble compounds: the di-Schiff base N,N′-bis(3-methoxy-5-sulfonatosalicylidene)-1,2-ethylenediamine disodium salt (MSS) and its corresponding Al(III) complex. To better understand the enol-imine (O-H···N) vs. keto-enamine (O···H-N) tautomeric behavior of MSS, we also considered its non-methoxy analogue (SS) as a reference compound. Using UV–vis absorption and diffuse reflectance spectroscopy, we examined the tautomeric preferences of MSS and SS in both the solid state and various solvents. The spectral features of MSS exhibited a noticeable bathochromic shift relative to SS in all media. In protic solvents (H2O, MeOH) and in the solid state, MSS is found predominantly in the keto-enamine form, while in aprotic polar solvents (DMSO, DMF), a mixture of keto and enol forms coexist. In contrast, SS shows a dynamic coexistence of both tautomeric forms in protic solvents, while the SS enol form becomes dominant in DMSO and DMF; in the solid-state SS predominantly adopts the keto-enamine form. These differences were rationalized in terms of electronic effects. The direct band gap energies were determined to be 2.75 eV for SS, 2.61 eV for MSS and 3.03 eV for the Al(III)/MSS complex, revealing their wide-band-gap-semiconductor character. These values were supported by DFT calculations, which were found to be able to reproduce the experimental trends and were also used to provide insight into the electronic structure of the studied compounds. Photoluminescence analysis revealed that MSS emits in the green region, while the Al(III)/MSS complex exhibits a blue-white emission, making both compounds promising candidates for application in single-layer white OLEDs. Additionally, the Al(III)/MSS complex displayed photocatalytic activity toward the degradation of methylene blue (MB), with a rate constant of 0.032 min−1, indicating its potential as a multifunctional material for both optoelectronic and environmental applications.