Amido-pyrrole, isophthalamide and calix[4]arene cleft-type receptors fpr anionic guests

This thesis reports the synthesis and study of anion association properties of novel organic anion receptors. A series of four 2,5-diamidopyrrole receptors have been shown to be effective anion receptors, with comparable affinities to simple 2,5-dicarboxamidopyrroles, while possessing a more flexible hydrogen bonding array. Six novel 2- and 2,5-bis(phenyl)hydrazinecarboxamidopyrrole receptors have been synthesised. The mono substituted receptors demonstrated low affinity for anions, while the 2,5-bis(4-nitrophenyl) and 2,5-bis(3,5-dinitrophenyl) derivatives showed a strong affinity for a range of anions in dimethylsulfoxide—d6, although no particular selectivity was observed. Two 2-(phenyl)hydrazinecarbothioamidopyrrole receptors have been shown to undergo deprotonation in the presence of fluoride, acetate, benzoate and dihydrogenphosphate and as a consequence show a strong colour change. Four isophthalamide receptors have been synthesised and found to form extended hydrogen bonded arrays in the solid state. Investigation of the association behaviour towards a range of anions in dimethylsulfoxide-d6 revealed the three fluorine containing derivatives showed an affinity for anions, but that the amide proton resonance disappeared in the presence of fluoride, benzoate and dihydrogenphosphate. A new class of imide linked macrocycle, which forms in a one step reaction in the absence of a template, has been identified and two examples synthesised. Two novel pyrrole appended p-tert-butylcalix[4]arene receptors show good affinity for fluoride and strong affinity for dihydrogenphosphate in dichloromethane-d2 solution. In both cases a 1:2 receptor to anion ratio is formed. The synthesis of two guanidinium appended p-tert-calix[4]arene salts has been achieved.