Correlating electronic structure with corrosion inhibition potentiality of some bis-benzimidazole derivatives for mild steel in hydrochloric acid: Combined experimental and theoretical studies

•Bis-benzimidazole derivatives as good corrosion inhibitors for mild steel in acid.•Simultaneous both way electron-transfer is expected to occur during adsorption.•Role of molecular conformation on inhibition efficiency is demonstrated.•Good correlation between inhibition efficiency and molecular parameters established.•MD simulation results support experimental observations.