Calixarenes are macrocyclic molecules, like crown ethers and cyclodextrins.1-7 Calixarenes made up of phenol and methylene units have many conformational isomers because of two possible rotational modes of the phenol unit: the oxygen-through-theannulus rotation and the para-substituent-throughthe-annulus rotation (Figure 1). The conformational isomers thus yielded afford a great number of unique cavities with the different size and the different shape. Recently, a number of strategies have been exploited by which not only the conformation of calix[4]arenes, but also those of calix[6]arenes and calix[8]arenes, can be immobilized. This means that our group can now design various calixarene-based receptors that show high selectivity for guest molecules and metal cations. In this review article, our group describe novel strategies for cavity design using calix[n]arene skeletons, strategies that are intended to allow complexation of specific molecular targets or metal ions.

Novel Cavity Design Using Calix[n]arene Skeletons: Toward Molecular Recognition and Metal Binding.

The challenge of cyclic and acyclic schiff bases and related derivatives

The affinities of hosts-ranging from small synthetic cavitands to large proteins-for organic molecules are well documented. The average association constants for the binding of organic molecules by cyclodextrins, synthetic hosts, and albumins in water, as well as of catalytic antibodies or enzymes for substrates are 10(3.5+/-2.5) M(-1). Binding affinities are elevated to 10(8+/-2) M(-1) for the complexation of transition states and biological antigens by antibodies or inhibitors by enzymes, and to 10(16+/-4) M(-1) for transition states with enzymes. The origins of the distributions of association constants observed for the broad range of host-guest systems are explored in this Review, and typical approaches to compute and analyze host-guest binding in solution are discussed. In many classes of complexes a rough correlation is found between the binding affinity and the surface area that is buried upon complexation. Enzymes transcend this effect and achieve transition-state binding much greater than is expected from the surface areas.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/anie.200200565

Binding Affinities of Host–Guest, Protein–Ligand, and Protein–Transition‐State Complexes

Calixarenes - the third generation of supramolecules

A diverse array of semiconductor-based composite materials have been prepared, characterized, and utilized in many applications ranging from photocatalysis, photovoltaic cells, photoelectrochromic displays, and light-emitting devices to sensors. The composite architectures (nanoarchitectures in many cases) are equally diverse. In this review, we highlight the advances that have been made and identify some of the gaps in our current knowledge of these materials. Size quantization effects and semiconductor quantum dots are also discussed.

https://www.uta.edu/cos/raj/pub/Chem.Mater.Review-1.pdf

Semiconductor-Based Composite Materials: Preparation, Properties, and Performance

Calixarenes. 23. the complexation and catalytic properties of water soluble calixarenes

Several facets of calixarene chemistry have been investigated including the mechanism of their formation by the base-induced condensation of phenols and formaldehyde, procedures for introducing functional groups onto the ‘upper rim’ and ‘lower rim’ of calixarenes, the conformational behavior of calixarene oxyanions, the formation of complexes in aqueous and nonaqueous systems, and the application of calixarenes as catalysts.

Topics in Calixarene Chemistry

First-principles Calculations to Investigate Structural, Electronics, Optical and Elastic Properties of Sn-based Inorganic Halide-perovskites CsSnX3 (X = I, Br, Cl) for Solar Cell Applications

Clusters of quantum-confined cadmium sulfide were prepared in acetonitrile employing p-[(dialkylamino)methyl]calix[n]arene (n=4, 5, 6, 7; alkyl=CH 3 , C 4 H 9 , C 6 H 13 ) macrocycles as molecular stabilizers. A systematic variation of the CdS to aminocalixarene ratio leads to three distinct regimes of average particle size and photophysical properties. The monitoring of the cluster properties with time reveals a dynamic Q-CdS surface approaching a common structure (as reflected in its emission spectrum) regardless of cluster size or initial photophysical characteristics

Iftikhar Alam

Papers

Calixarenes. 23. the complexation and catalytic properties of water soluble calixarenes

Topics in Calixarene Chemistry

First-principles Calculations to Investigate Structural, Electronics, Optical and Elastic Properties of Sn-based Inorganic Halide-perovskites CsSnX3 (X = I, Br, Cl) for Solar Cell Applications

An examination of the interfacial interactions between quantum-confined cadmium sulfide clusters and aminocalixarene stabilizer molecules