1-Benzoyl-3,3-diphenylthiourea (1), 1-benzoyl-3,3-dibenzylthiourea (2), 1-benzoyl-3,3-diethylthiourea (3), 1benzoyl-3,3-dibutylthiourea (4), 1-benzoyl-3,3-bis(2-methylpropyl)thiourea ( 5), and 1-benzoyl-3,3-bis(propan-2-yl)thiourea ( 6) were synthesized and investigated as inhibitors for the corrosion of the surface of mild steel in 1.0 M HCl by chemical and electrochemical measurements. The inhibition efficiencies obtained from different methods were in good agreement with each other. Inhibitor 2 showed a higher inhibition efficiency according to all of the methods. The Tafel polarization method revealed the mixed-mode inhibition of inhibitors with predominant control of the anodic reaction. At all studied temperatures, the adsorption of the inhibitor molecules onto the steel surface was found to follow the Langmuir adsorption isotherm. The values of the Gibbs free energy of adsorption strongly supported spontaneous chemical and/or physical adsorption of inhibitor molecules. The adsorption mechanism for inhibition was supported by ultraviolet−visible (UV−vis), Fourier transform infrared (FTIR), Raman, and scanning electron microscopy−energy-dispersive X-ray (SEM−EDS) spectroscopic methods, and adsorption isotherm measurements. The crystalline/amorphous nature of the inhibitors adsorbed onto the mild steel surface was indicated by wide-angle X-ray diffraction (WAXD) analysis.

Self-assembled metallamacrocyclic Cu(II) and Ni(II) complexes of the types [Cu(L1-O,S)]3 (1), [Ni(L1-O,S)]3 (2), [Cu(L2-O,S)]2 (3) and [Ni(L2-O,S)]2 (4) [H2L1 = 3,3,3',3'-tetrabenzyl-1,1'-terephthaloylbis(thiourea) and H2L2 = 3,3,3',3'-tetrabenzyl-1,1'-isophthaloylbis(thiourea)] were synthesized and characterized by analytical, spectroscopic (UV-Vis, FT-IR, mass, (1)H & (13)C NMR and EPR) and single crystal X-ray diffraction techniques. The crystal structures of [Ni(L1-O,S)]3 and [Cu(L2-O,S)(Py)]2 showed the formation of self-assembled 3:3 and 2:2 metallamacrocyclic Cu(II) and Ni(II) complexes respectively. The binding affinity and binding mode of the trinuclear complexes toward CT DNA were determined by UV-Vis spectrophotometric titrations and the fluorescent indicator displacement (FID) assay. The interaction of the ligand (H2L1) and the complexes (1 and 2) with BSA was investigated using UV-Vis and fluorescence spectroscopic methods. Absorption and emission spectral studies indicate that the complexes 1 and 2 interact with CT DNA and BSA protein more strongly than their parent ligand. Both the complexes (1 and 2) cleaved the pBR 322 plasmid DNA in the absence of an external agent. Complex 1 [IC50 = 22.36 (A549) and 10 μM (MCF7)] exhibited higher cytotoxicity than cyclophosphamide against A549 and MCF7 cancer cell lines. The IC50 value of 2 (29.24) is lower in the A549 cell line and slightly higher (18.04) in the MCF7 cell line than that of cyclophosphamide [IC50 = 41.84 (A549) and 11.89 μM (MCF7)].

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Deoxyribonucleic acid (DNA) and a self-doped conjugated polyelectrolyte, poly (4-(2,3-dihydrothieno[3,4-b]- [1,4]dioxin-2-yl-methoxy)-1-butanesulfonic acid (PEDOT-S), are assembled for organic optoelectronics and bioelectronics. The DNA's helix−coil phase transition in water is studied as a function of composition by thermo-optical analysis. DNA and PEDOT-S are functionalized by using a surfactant, cetyltrimethylammonium chloride (CTMA), and DNA:CTMA, PEDOT-S:CTMA, and DNA:CTMA:PEDOT-S:CTMA complexes were characterized regarding thermal, optical, morphological, and structural properties. Finally, DNA and DNA:PEDOT-S mixtures are processed in water for fabricating organized films through brushing. The electrical properties of these films are characterized using an interdigitated electrode. The films show an electronic conductivity of ∼10 −6 −10 −5 S/cm in a range of semiconductors.

Four different copper complexes containing aroylthiourea ligands displayed good interaction with CT DNA and BSA and cytotoxicity.