Experimental and theoretical study of two Salen-type Schiff bases: green synthesis, characterization, corrosion inhibition efficiency, and biological activity

As eco-friendly corrosion inhibitors, antioxidants, and antibacterial agents, this study assesses 1,3-bis(2-hydroxybenzylidene) thiourea (B1) and 1,3-bis(2-hydroxybenzylidene) urea (B2), two new Schiff bases, on their performance in these areas. We successfully synthesized these Schiff bases in just 15 minutes using an environmentally friendly approach, and the yield was rather good, ranging from 69.8% to 87.53%. When compared to B2, B1 showed more effective corrosion inhibition and better antioxidant activity. Both chemicals were highly effective against microbes, while B1 was particularly effective against Aspergillus. B. We measured the weight loss to examine the corrosion inhibition impact of XC48 carbon steel in 1M HCl. The findings revealed that at the ideal concentration of 5.10–4 M, the estimated IE% of the Schiff bases was 63.8% for B2 and 87.28% for B1. This study employed the Langmuir isotherm model to determine a number of thermodynamic and kinetic characteristics, all of which pointed to a physical adsorbed state. Promising electrical characteristics and robust adsorption on metal surfaces for B1 were corroborated by theoretical investigations employing density functional theory (DFT) and molecular dynamics (MD) simulations. Both the theoretical and practical aspects align with one another.