Synthesis, spectral characterization, molecular modeling, antibacterial and antioxidant activities and stability study of binuclear Pd(II) and Ru(III) complexes with novel bis-[1-(2-[(2-hydroxynaphthalen-1-yl)methylidene]amino}ethyl)-1-ethyl-3-phenylthiourea] ligand: Application to detection of cholesterol

Abstract

A novel bis-[1-(2-[(2-hydroxynaphthalen-1-yl) methylidene]amino}ethyl)-1-ethyl-3-phenylthiourea] Schiff base (L) and its binuclear palladium and ruthenium complexes have been prepared and characterized by ESI-MS, elemental analysis, NMR (H NMR, C NMR, COSY, NEOSY and HSQC), FT-IR, ATR, UV-Visible spectra, TGA measurements, conductivity and cyclic voltammetry. The experimental results and the molecular parameters calculated using DFT method revealed a square planar geometry around Pd and octahedral geometry around ruthenium metal. The antibacterial activity of the ligand L and its complexes was evaluated against different human bacteria. In addition, the formation constants of the synthesized Schiff base-metal complexes and the systems formed with these chelates and cholesterol were estimated using spectrophotometric technique. The detection of cholesterol using novel Pd and Ru Schiff base complexes was studied using fluorometric method, and the measurements showed that the sensitive fluorometric response towards cholesterol analysis was determined using palladium complex. The limit of detection (LOD) of cholesterol calculated using this complex (4.6 μM) is lower (better) than LOD found using ruthenium complex (19.1 μM) and different compounds previously published around linear range of 0-5 mM.

Catalytic and antibacterial properties of 3‐dentate carboxamide Pd/Pt complexes obtained via a benign route

“…Therefore, efforts have recently been made to design novel anticancer drugs based on palladium compounds . In addition, these compounds have attracted renewed interest due to their wide applications in catalytic processes, construction of chemical sensors, and antibacterial and cytotoxicity usage …”

Novel 2‐formylpyridine 4‐allyl‐S‐methylisothiosemicarbazone and Zn(II), Cu(II), Ni(II) and Co(III) complexes: Synthesis, characterization, crystal structure, antioxidant, antimicrobial and antiproliferative activity

“…The intense bands in the spectrum of ligand at 1638 and 1585 cm −1 assigned to ν(C=N) and is shifted with up to 15–27 cm −1 , in all the complexes, suggesting the coordination of the azomethine nitrogen.…”

New “one‐pot” Pd(II) and Zn(II) complexes of Schiff bases, derivatives of 1‐amino‐1‐deoxy‐d‐sorbitol: Spectroscopic studies and biological and catalytic activities

“…Complexes of Schiff bases play an important role in the detection of various ions, exhibit biological properties, and are widely used as catalysts . Recently, several studies focused on Schiff bases and their complexes, derivatives of natural products, for example, amino sugars, amino acids, and chitosan . Identifying new enantiomerically pure systems is one of the major goals of organic chemistry.…”

“…All complexes presented cell viability higher than 50%, and zinc(II) complex was the most soluble species in the series of studied complexes. Palladium(II) complexes, derivatives of substituted salicylaldehydes, showed a remarkable antimicrobial activity against Bacillus subtilis , while palladium complexes that are the derivative of 2‐hydroxynaphthaldehyde showed an important antioxidant activity and can be used as a sensor for detecting cholesterol (limit of detection [LOD] value of 4.6μM) . Such reports were the starting point to our studies.…”

“…To the best of our knowledge, most studies on complexes of amino sugar Schiff bases deal sugars deal with compounds containing moiety other than d ‐glucamine and rather in ring form . Only a few studies deal with compounds containing sugar chain moiety, and therefore d ‐glucamine as a reactant in the synthesis of Schiff bases is an unexplored chiral raw material. Our primary aim was a convenient “one‐pot” synthesis of new optically active zinc(II) and palladium(II) complexes, derivatives of natural products such as d ‐glucamine; their spectroscopic characterization; and preliminary tests for biological and catalytic activities.…”