Synthesis, in vitro and theoretical studies on newly synthesized deep blue emitting 4-(p-methylphenylsulfonyl-5-aryl/alkyl)oxazole analogues for biological and optoelectronic applications

Abstract

• Simple, facile and novel methodology for the synthesis of 4-Ts-5(alk/Ar/Het-Ar)-disubstituted oxazoles. • Evaluation of in vitro anti-bacterial and anti-fungal activities (up to 1 µg/mL) and molecular modelling studies. • The ORTEP view of the molecules was obtained with displacement ellipsoids drawn at 50% probability level. • Estimation of ground and excited state dipole moments by solvatochromic shift method. • Computational studies of Global Chemical Reactivity Descriptor (GCRD) Parameters (η, µ, S, χ and ω). • Theoretical estimation of Molecular electrostatic potential (MESP) plots and HOMO-LUMO gap using B3LYP/6-311G(d). In the present study, a series of 4,5-di-substituted oxazole derivatives ( compound s 2a-p ) were synthesized, using a novel methodology for the simultaneous determination of their biological and optoelectronic applications. Among the screened molecules, compounds 2j, 2 l and 2o showed very good antimicrobial potencies with MICs up to 1 µg/mL. Furthermore, the photophysical parameters were estimated using theoretical and experimental techniques for optoelectronic applications. The excited-state dipole moment being higher than that of the ground state, investigated using solvato-chromatic method showed a redistribution of the electron densities in the excited state for the fluorophores. The HOMO-LUMO energies of the fluorophores estimated by using density functional theory (DFT) are found to be in good agreement with the experimental values. The electrophilic and nucleophilic sites were also recognized with the help of molecular electrostatic potential 3D plots using time-dependent-DFT computational analysis. The specific and non-specific interactions between the solute–solvent were analyzed by multiple linear regression analysis using Kamlet-Abound-Taft and Catalan parameters. Further, the global chemical reactivity descriptor parameter was also calculated. The photophysical properties of the fluorophores suggest that these may be considered as potential probes for OLED, solar cell, and chemosensor applications.