Synthesis, characterization and micellization behaviour of some surface active mixed-ligand complexes of cobalt(III)

Metallosurfactant aggregates: Structures, properties, and potentials for multifarious applications

Metallosurfactants offer important scientific and technological advances due to their novel interfacial properties. As a special class of structures formed by the integration of metal ions into amphiphilic surfactant molecules, these metal-based amphiphilic molecules possess both organometallic and surface chemistries. This review critically examines the structural transitions of metallosurfactants from micelle to vesicle upon metal coordination. The properties of a metallosurfactant can be changed by tuning the coordination between the metal ions and surfactants. The self-assembled behavior of surfactants can be controlled by selecting transition-metal ions that enhance their catalytic efficiency in environmental applications by applying a hydrogen evolution reaction or oxygen evolution reaction. We present the different scattering techniques available to examine the properties of metallosurfactants (e.g., size, shape, structure, and aggregation behavior). The utility of metallosurfactants in catalysis, the synthesis of nanoparticles, and biomedical applications (involving diagnostics and therapeutics) is also explored.

Assessment of the aggregation and adsorption behavior of newly synthesized tetradecylpyridinium-based metallosurfactants and their interaction with bovine serum albumin

Tetradecylpyridinium (TP) based metallosurfactants, TP₂[MCl₄] (M = Mn, Co, Ni, Cu, Zn): synthesis, aggregation behavior and interaction with bovine serum albumin.

Electrochemical co-deposition synthesis of Au-ZrO2-graphene nanocomposite for a nonenzymatic methyl parathion sensor

For the first time, a simple electrochemical co-deposition was utilized to synthesis the gold and zirconia nanocomposites modified graphene nanosheets on glassy carbon electrode (Au-ZrO₂-GNs/GCE) for electrocatalytic analysis of methyl parathion (MP). According to Field-Emission Scanning Electron Microscopy (FE-SEM), Transmission Electronic Microscopy (TEM) and X-Ray Diffraction (XRD), the gold nanoparticles were uniformly distributed on the surface of graphene-based nanocomposite. The Au-ZrO₂-GNs/GCE based sensor exhibited superior capacity for MP detection, ascribed to the strong affinity of zirconia towards the phosphoric group, as well as the high catalytic activity and good conductivity of Au-GNs. The best fabrication and work conditions were then obtained by systematically optimization of the electrodeposition process, pH value and enrichment time. Compared to the gold nanoparticles, zirconia or graphene modified electrodes, AuZrO₂-GNs/GCE sensor displayed superior electro-catalytic response toward MP oxidation. The sensor response current of square wave voltammetry was highly linearly correlated with the MP concentrations range of 1-100 ng mL^-1 and 100-2400 ng mL^-1 with the detection limit of 1 ng mL^-1. The Au-ZrO₂-GNs/GCE nanocomposite sensor showed excellent accuracy and reproducibility for detection of MP in Chinese cabbage samples, providing a new method for efficient pesticide detection in practical applications.

Synthesis, characterisation and self-assembly behaviour of emissive surfactant–ruthenium(ii) complexes

Bipyridine/phenanthroline based dodecylamine/hexadecylamine containing surfactant–ruthenium(ii) complexes form green fluorescent vesicles with an excellent stability in the aqueous medium.

A comparative study on the binding of single and double chain surfactant-cobalt(III) complexes with bovine serum albumin

The comparative binding effect of single and double aliphatic chain containing surfactant-cobalt(III) complexes cis-[Co(bpy)2(DA)2](ClO4)3·2H2O (1), cis-[Co(bpy)2(DA)Cl](ClO4)2·2H2O (2), cis-[Co(phen)2(CA)2](ClO4)3·2H2O (3), and cis-[Co(phen)2(CA)Cl](ClO4)2·2H2O (4) with bovine serum albumin (BSA) under physiological condition was analyzed by steady state, time resolved fluorescence, synchronous, three-dimensional fluorescence, UV-Visible absorption and circular dichroism spectroscopic techniques. The results show that these complexes cause the fluorescence quenching of BSA through a static mechanism. The binding constants (Kb) and the number of binding sites were calculated and binding constant values are found in the range of 10(4)-10(5) M(-1). The results indicate that compared to single chain complex, double chain surfactant-cobalt(III) complex interacts strongly with BSA. Also the sign of thermodynamic parameters (ΔG°, ΔH°, and ΔS°) indicate that all the complexes interact with BSA through hydrophobic force. The binding distance (r) between complexes and BSA was calculated using Förster non-radiation energy transfer theory and found to be less than 7 nm. The results of synchronous, three dimensional fluorescence and circular dichroism spectroscopic methods indicate that the double chain surfactant-cobalt(III) complexes changed the conformation of the protein considerably than the respective single chain surfactant-cobalt(III) complexes. Antimicrobial studies of the complexes showed good activities against pathogenic microorganisms.

Synthesis, Spectroscopy, and Magnetic Characterization of Copper(II) and Cobalt(II) Complexes with 2-Amino-5-bromopyridine as Ligand

The synthesis, spectroscopic, and magnetic characterization of two new copper(II) and cobalt(II) complexes are described. Both two compounds have the general formula [M(L)2(Cl)2], in which L= 2-amino-5-bromopyridine. These complexes were prepared in one-step synthesis and characterized by elemental analysis, FTIR, UV-Vis, and EPR spectroscopy. Moreover, the single crystal structure of complex (1) was studied by the X-ray diffraction method. This compound consists of mononuclear units consisting of two ligands linked to metal via the nitrogen of pyridine ring. The UV-Vis spectra of copper(II) and cobalt(II) complexes show three and five absorption bands, respectively, attributed to the d-d transition of the metal ion, ligand → metal charge transfer, and π→π∗ or n→π∗ transitions of the ligand. The FTIR spectra show MN2Cl2 vibrations at 500–300 cm−1. The complexes show room temperature magnetic moments of 1.78 BM and 4.12 BM for Cu(II) and Co(II), respectively. The X-band electron spin resonance (ESR) spectra of Cu(II) complex in DMF or DMSO frozen at liquid nitrogen temperature show the typical ΔMS=±1 transition.

Determination of iron(III) by room temperature ionic liquids/surfactant sensitized fluorescence quenching method

A new method for the determination of iron (III) has been described. The analytical procedure was based on the fluorescence quenching of salicylfluorone (SAF) by iron (III) and the fluorescence quenching value (ΔF) could be increased in the medium of room temperature ionic liquids (RTILs) (1-ethyl-3-methylimidazolium ethyl sulfate)/SDS (sodium dodecyl sulfate). The main factors influencing the fluorescence quenching (ΔF) were investigated in detail. Under the optimal conditions, the linear equation was [Formula: see text](c:μg·mL(-1), r = 0.9936). The linear range of calibration curve was 0.2-1.1 μg·mL(-1) and the detection limit was 8.3 ng·mL(-1). The preliminary sensitized mechanism was discussed with distribution coefficient and fluorescence quantum yield in different media. The method has been applied to the determination of Fe (III) in water samples with satisfactory results.