Optical parameters of thin calixarene films and their response to benzene, toluene and chloroform adsorption

Coordination-Driven Monolayer-to-Bilayer Transition in Two-Dimensional Metal-Organic Networks

We report on monolayer-to-bilayer transitions in 2D metal-organic networks (MONs) from amphiphiles supported at the water-air interface. Functionalized calix[4]arenes are assembled through the coordination of selected transition metal ions to yield monomolecular 2D crystalline layers. In the presence of Ni(II) ions, interfacial self-assembly and coordination yields stable monolayers. Cu(II) promotes 2D coordination of a monolayer which is then diffusively reorganizing, nucleates, and grows a progressive amount of second layer islands. Atomic force microscopic data of these layers after transfer onto solid substrates reveal crystalline packing geometries with submolecular resolution as they are varying in function of the building blocks and the kinetics of the assembly. We assign this monolayer-to-bilayer transition to a diffusive reorganization of the initial monolayers owing to chemical vacancies of the predominant coordination motif formed by Cu²⁺ ions. Our results introduce a new dimension into the controlled monolayer-to-multilayer architecturing of 2D metal-organic networks.

Calixarene–polymer hybrid film for selective detection of hydrocarbons in water

Designing calixarene–polymer composites for enhanced molecular detection of neutral and low molecular weight hydrocarbons in aquatic environments.

Analytical evaluation of Cu2+ selective behavior of calix[4]arene derivative

The present article describes the solvatochromic effect including solvent system selection, time study and a detailed complexation study along with exploration of extraction properties of 5,11,17,23-tetrakis[(diethylamino)methyl]-25,26,27,28-tetrahydroxycalix[4]arene (4) that bears nitrogen atom as a donor group available for chelating metal ions. Complexation properties of 4 toward selected transition metal ions have been investigated by UV-visible and fluorescence spectroscopies. The% efficiency of 4 toward selected transition metal ions was found in order Cu(2+)>Ni(2+)>Hg(2+)>Zn(2+)>Co(2+)>Cd(2+)>Pb(2+). It has been noticed that 4 is not only proved to be an efficient Cu(2+) selective chromoionophore but also possesses an effective extraction property for transferring Cu(2+) ions from an aqueous to dichloromethane layer. The FT-IR spectroscopic method has also been applied for further confirmation of the complexation phenomenon of 4 with Cu(2+) ion and found adequate.