Arenes In Cone Conformation Research Articles

Sulfobetaine derivatives of thiacalix[4]arene: synthesis and supramolecular self-assembly of submicron aggregates with AgI cations

Sulfobetaine derivatives of p-tert-butylthiacalix[4]arene in cone conformation have been synthesized for the first time. It has been shown by dynamic light scattering that the compounds form submicron-sized particles with silver cation in water, and the particle size depends on the length of a linker in the sulfobetaine moiety.

New Amphiphilic Bowl-Shaped Receptors on the Basis of Calix[4]arenes in Cone Conformation: Synthesis, Self-Aggregation and Eosin Y Dye Binding

New Amphiphilic Bowl-Shaped Receptors on the Basis of Calix[4]arenes in Cone Conformation: Synthesis, Self-Aggregation and Eosin Y Dye Binding

Microwave‐Assisted Synthesis of a Nitro‐m‐xylylenedioxycalix[6]arene Building Block Functionalized at the Upper Rim

AbstractMicrowave‐assisted synthesis represents a new methodology to obtain calix[6]arene building blocks. The synthesis of compounds 1 and 2 is described. These compounds are A,D‐m‐xylylenedioxy‐bridged calix[6]arenes in cone conformation, functionalized with potential amino groups in the lower rim spacer (5‐position) and amino groups or their precursors in A,D‐para positions at the upper rim. A conformational study has been performed for all newly synthesized compounds.

A New Class of Potassium-selective Calix[4]arenes in Cone Conformation

Benzoate modified calix[4]arenes 3–8 were synthesized from (o-bromomethyl)benzoate. EA, IR, 1H and 13C NMR characterizations showed that compounds 3, 4, 5, 7 and 8 were in cone conformation, while 6 was in a 1,3-alternate conformation. The solvent extraction experiments found that the cone-conformers 3 and 8 have high selectivity for K+ as compared to Na+. Compound 3 has an extractability of 69.8% for K+ and 7.1% for Na+. Compound 8 has an extractability of 80.9% for K+ and 19.1% for Na+. In order to elucidate the results, the complex behavior of compounds 3, 6 and 8 for K+ were studied by 1H NMR and the crystal structures of compounds 3 and 6 were determined.

Tetra(diethyl)amide-p-tert-butyl-thiacalix[4]arene in Cone Conformation: Synthesis and Binding Properties with Alkali, Alkaline Earth, Heavy and Transition Metal Ions

Tetra(diethyl)amide-p-tert-butylthiacalix[4]arene 1a in the cone conformation was synthesized and its binding properties towards a large variety of metal ions were established on the basis of liquid–liquid and solid–liquid extraction as well as complexation experiments. This compound is a less efficient and selective compound than the “classical” tetra(diethyl)amide-p-tert-butylcalix[4]arene 3 in the cone conformation for alkali and alkaline earth metal ions. However, Pb2+ is selectively extracted and complexed within heavy and transition metal ions.

Synthesis of Doubly Azacrowned Thiacalixarenes.

Under selected conditions, 1,2:3,4-doubly crowned p-tert-butyl-thiacalix[4]arene in cone conformation and 1,3:2, 4-doubly crowned p-tent-butyl-thiacalix[4]arene in 1,3-alternate conformation were obtained through aminolysis in high to good yield, respectively.

Synthesis of Doubly Azacrowned Thiacalixarenes

Under selected conditions, 1,2:3,4-doubly crowned p-tert-butyl-thiacalix[4]arene in cone conformation and 1,3:2, 4-doubly crowned p-tert-butyl-thiacalix[4]arene in 1,3-alternate conformation were obtained through aminolysis in high to good yield, respectively.

Molecular tectonics: design and structural analysis of 1-D and 2-D self-inclusion molecular networks in the crystalline state

The synthesis of the new symmetrical koiland 2 based on the double fusion of two p-ethylcalix〚4〛arene in cone conformation by two silicon atoms was achieved and its structure confirmed by X-ray diffraction on a single crystal. Koiland 2, a concave building block possessing two calix-type pre-organised cavities disposed in a divergent fashion as well as ethyl groups as potential connector moieties, affords either a discrete exo-binuclear inclusion complex in the solid state in the presence of p-xylene acting as a stopper or infinite 1-D or 2-D self-inclusion networks or koilates, mainly based on van der Waals interactions and resulting from the inclusion processes taking place between concave and convex moieties of consecutive koilands.

Molecular tectonics: design, synthesis and structural analysis of a molecular network based on inclusion processes using a doubly fused p-isopropylcalix[4]arene

The synthesis of a hollow molecular module (koiland) possessing two divergent cavities was achieved by double fusion of two p-isopropylcalix[4]arenes in cone conformation by two silicon atoms. The formation of either a discrete binuclear inclusion complex in the presence of CH 2 Cl 2 acting as stopper or of an infinite 1-D inclusion network (koilate) in the presence of hexadiyne acting as connector was demonstrated in the solid state by single-crystal diffraction studies. The inclusion network was based on the interconnection of consecutive koilands by connector molecules.

Calix[4]Arenes in the partial cone conformation as ionophores in silver ion‐selective electrodes

AbstractTwo calix[4]arene derivatives, in the partial cone conformation, with sulfur‐containing functionalities, were tested as neutral carrier ionophores in potentiometric silver‐selective electrodes of conventional membrane and membrane‐coated glassy carbon electrode types. Comparison with a calix[4]arene in the cone conformation was made. The membranes were prepared using either 2‐nitrophenyl octyl ether or bis(ethylhexyl)sebacate as plasticizers and potassium tetrakis(p‐chlorophenyl)borate as the lipophilic salt in a poly(vinyl chloride) matrix. Both calix[4]arenes yielded electrodes of good sensitivity (approx. 47 mV dec−1) in the range 10−4–10−1 M and excellent selectivity [log KAg,MH+ < −1.5] of transition, alkali and heavy metal cations, including sodium, mercury(II) and lead(II) cations. Temperature effects and reproducibility of response were determined and the interfering effects of mercury(II) and lead (II) ions on the membranes were noted. The partial cone conformation allows improved selectivity over certain cations relative to calix[4]arenes in the cone conformation.