Low temperature photoluminescence and solvatochromic studies of organic hybrid 4-methoxybenzylammonium chloride (4-MBACl)

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2021-05, Vol.253, p.119575, Article 119575
• Main Authors: Anu Ranjani, E., Sangeetha, K., Joseph Daniel, D., Karthick, T.
• Format: Article
• Language: English
• Subjects: Exciton-phonon coupling; J-aggregates; Optical band gap; Solvatochromism; π electron delocalization
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2021.119575

[Display omitted] •4-MBACl crystal is an UV emitter (300 nm) from temperature 10–290 K.•Exciton-phonon coupling in 4-MBACl is realized by temperature dependent photoluminescence studies.•Significant factors that alter the optical band gap of 4-MBACl are solvent polarity, proticity and solution concentration.•Inter-molecular interactions (OH—O and OH—π) between solvent and 4-MBACl lead to hypsochromic shifts in absorption.•Absorption bathochromic shift is caused by π-π stacking between adjacent parallel-displaced 4-MBACl molecules. We report temperature dependent photoluminescence (PL) and solvatochromic studies of 4-methoxybenzylammonium chloride (4-MBACl). The single crystals of 4-MBACl has been grown using slow solvent evaporation method under ambient conditions and have been confirmed using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic studies. Thermal stability of the material has been analyzed by thermogravimetric (TG) and differential thermal analyzes (DTA). 4-MBACl crystal is photoluminescent with emission wavelength maximum at 300 nm. Exciton-phonon coupling in 4-MBACl is realized from temperature dependent PL studies. Changes in full width at half maximum (FWHM) of PL emission peak, intensity maximum (Imax) and wavelength maximum (λmax) have been analyzed systematically between temperatures 290–10 K in order to understand the photophysical phenomenon behind the emission. Optical band gap (Eg) of 4-MBACl has been varied using solvent polarity, proticity and solution concentration. Interactions like OH---O, OH---π and π-π stacking are explained to reason the notable shifts.