The role of solvent in molecular recognition systems is under-researched and often ignored, especially when the solvent is considered "non-interacting". This study concerns the role of toluene solvent in cesium(i) recognition by calix[4]pyrrole. We show that π-donor interactions bind toluene molecules onto the open face of the cation-receptor complex, thus "capping the calix." By characterizing this unusual aromatically-saturated complex, we show how "non-interacting" aromatic solvents can directly coordinate receptor-bound cations and thus influence recognition.
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http://dx.doi.org/10.1039/c7cc02347b | DOI Listing |
Food Chem
August 2024
HEJ Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, 75270, Pakistan. Electronic address:
In this report, we firstly synthesized nitro calix [4] resorcinarene compound (referred as KA30) and characterized it though proton (H) nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and Fourier Transform Infra-red (FTIR) spectroscopy. KA30 was applied as functionalizing agent for the formation of silver nanoparticles (KA30-AgNPs). These NPs were confirmed as highly selective and extremely sensitive colorimetric sensor for ultra-low level detection of emamectin (EMA) as a novel report.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
May 2024
Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
The highly strained, phenylene-derived organic cages are typically regarded as very rigid entities, yet their deformation potential and supramolecular properties remain underexplored. Herein, we report a pliable conjugated phenylene nanocage by synergistically merging rigid and flexible building blocks. The anisotropic cage molecule contains branched phenylene chains capped by a calix[6]arene moiety, the delicate conformational changes of which endow the cage with a remarkably deformable cavity.
View Article and Find Full Text PDFAnal Sci
December 2023
International Center for Chemical and Biological Science, HEJ Research Institute of Chemistry, University of Karachi, Karachi, 75270, Pakistan.
In the current study, one of the outstanding facile and simple protocols is proposed for the synthesis of copper nanoparticles (CuNPs) using NaBH as a reducing agent and p-tetranitrocalix[4]arene (p-TNC4) as a capping agent. According to our knowledge, no such technique is available in the literature for colorimetric detection of cyclophosphamide (CPA) using CuNPs at the trace level. The well-organized synthesis was confirmed via advanced spectroscopic techniques.
View Article and Find Full Text PDFDalton Trans
July 2023
EastCHEM School of Chemistry, The University of Edinburgh, David Brewster Road, Edinburgh, Scotland, EH9 3FJ, UK.
Reaction of 2,2'-bis--Bu-calix[4]arene (HL) with Cu(NO)·3HO and -methyldiethanolamine (Me-deaH) in a basic dmf/MeOH mixture affords [CuII16(L)(Me-dea)(μ-NO)(μ-OH)(dmf)(MeOH)(HO)](HL)·16dmf·4HO (4), following slow evaporation of the mother liquor. The central core of the metallic skeleton describes a tetracapped square prism, [Cu], in which the four capping metal ions are the Cu ions housed in the calix[4]arene polyphenolic pockets. The [CuII8] square prism is held together "internally" by a combination of hydroxide and nitrate anions, with the -methyldiethanolamine co-ligands forming dimeric [CuII2] units which edge-cap above and below the upper and lower square faces of the prism.
View Article and Find Full Text PDFJ Org Chem
September 2021
Laboratoire de Chimie Organique, Université libre de Bruxelles (ULB), Avenue F.D. Roosevelt 50, CP160/06, B-1050 Brussels, Belgium.
A molecular capsule based on a calix[6]arene core closed at the small rim by a three-point coordinated metal ion and at the large rim by a three-point covalent capping is described. It is derived from a trisimidazole funnel complex capped by a trenamide unit that prevents in/out exchange of guest molecules through the large rim. A detailed comparative study with three different calixarenes provides a unique opportunity for (i) comparing the binding ability of two different coordination sites in well three-dimensional (3D)-structured macrocyclic receptors and (ii) evaluating the impact of a covalent closing of one rim of a funnel receptor while the other rim is closed by weaker coordination bonds.
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