Supramolecular chemistry

Abstract

The following review describes significant advances in the field of supramolecular chemistry for the year 2006. As for previous articles in this series, it is not a comprehensive treatment of the literature. The review is split into three sections covering (i) molecular recognition, (ii) structure and assembly and (iii) functional systems. View Online entire system, self-sorting must necessarily occur. Interestingly the authors also observed an extremely slow dissociation rate (8.5 Â 10 À10 s À1 ) for disassembly of 3.6, which, married with its relatively low affinity, would make it an ideal motif for applications such as affinity chromatography.Anion recognition also remains a key goal in supramolecular chemistry. Gale and co-workers have reported on the different anion binding modes observed for the binding interactions of macrocyclic amidourea 7. 7 They found that carboxylates bound with high-affinity in 0.5% water in DMSO as observed by 1 H NMR titration, but that phosphates and chloride bound less well. The behaviour was attributed to the different binding geometry that each anion class could adopt. For carboxylates, downfield changes in chemical shift were observed for the urea protons and the dicarboxamidopyridine, whereas only the latter underwent changes for phosphate. For chloride, downfield shifts were observed for the urea protons but upfield shifts for the dicarboxamidopyridine, suggesting solvent reorganization presumably due to a lack of shape complementarity for this anion.Anthony Davis and co-workers devised a synthesis of the triamino derivative of methyl allocholate which could be functionalized with isocyanates to form a receptor 8 for various anions (AcO À , EtSO 3 À , Cl À , Br À , NO 3 À , I À , ClO 4 À ). 8 The derivative 8 was found to bind these anions with affinities almost double that observed for the more established tris-urea derivative of cholic acid 9. This was rationalized by the fact that in the original cholapod 9, free rotation about the amine at position 3 results in formation of intramolecular hydrogen-bonds, whereas unfavourable diaxial interactions prevent this in the new derivative 9.

Quinazoline–benzimidazole hybrid as dual optical sensor for cyanide and Pb2+ ions and Aurora kinase inhibitor

“…Compounds constructed for sensing of cations [1][2][3][4][5][6][7][8] and anions based on UV-Vis and fluorescence techniques are extensively being investigated. The use of optical sensor for detection of low levels of heavy and transistion metal ion contamination has been a significant issue due to their toxicity to living organisms [9][10][11][12].…”

Supramolecular chemistry

“…The goal of supramolecular chemistry 1,2 i.e. the chemistry of non-covalent bonding is the design, synthesis and characterisation of host-guest complexes or assemblies under a defined set of conditions.…”