A new ternary ruthenium(III) complex with 1,3-bis(salicylideneamino) propan-2-ol and 3-picolylamine: Synthesis, characterization, density functional theory and preparation of electrochemical sensor for nitrite analysis

•Ternary Ru(III) complex with 1,3-bis(salicylideneamino)propan-2-ol (BSAP) and 3-picolylamine (PLA) was prepared.•The complex was characterized and studied by DFT calculations.•Graphite-Ru(III)-BSAP-PLA material was prepared and characterized by SEM-EDS techniques.•Cavity microelectrode (CME) was modified with graphite-Ru(III)-BSAP-PLA material.•Substential electro catalytic effect of Ru(III)-BSAP-PLA on oxidation of NO2− was observed.

A novel electrochemical sensor based on graphite (G) functionalised with a new ternary ruthenium(III) complex was developed and applied to detect nitrite in aqueous solution. The Ru(III) complex was synthesized using 1,3-bis(salicylideneamino) propan-2-ol polydentate Schiff base (BSAP) and 3-Picolylamine (PLA), and was characterized by elemental analysis, Fourier transform infrared spectroscopy (FT-IR), Ultraviolet–visible spectrophotometry (UV–Visible), gradient-assisted hetero nuclear single quantum coherence spectroscopy (gHSQC) and cyclic voltammetry technique. In addition, the structure of the synthesized complex was optimized using density functional theory (DFT). The results showed that the ternary Ru(III)–BSAP–PLA complex was formed and the adapted structure was an tetrahedral geometry.The electrochemical behavior of nitrite at the sensor prepared using G/Ru(III)–BSAP–PLA composite shows that the evaluated electron transfer coefficient (α = 0.83) indicates a very significant electrocatalytic mechanism for oxidation of nitrite in the presence of the Ru(III)–BSAP–PLA complex.Comparing to other published works, the sensor developed using G/Ru(III)–BSAP–PLA exhibited low limit of detection (LOD = 1.81 μM) around pH = 7.

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