Synthesis, Characterization And Anion Recognition Properties Of Side-armed Benzo-15-crown-5 Derivatives

4 ' -acetylbenzo-15-crown-5 is a very important intermediate in organic synthesis.We make it react with hydrazide and thiosemicarbazide, respectively, to get crowned acetylhydrazone and thiosemicarbazone. A single crystal of crowned acetylhydrazone obtained and the structure was resolved, at the same time the anion recognition property of crowned thiosemicarbazone was studied.1 Review on the crowned imine derivativesAccording to the different substituents of nitrogen atom of imine, the crowned imine derivatives were devided into crowned Schiffbase, crowned hydrazone and acylhydrazone (including thiosemicarbazone), and their researches were reviewed.2 The synthesis characterization and single crystal structure of 4 ' -acetylbenzo-15-crown-5 2-aryloxyacetylhydrazoneThe 4' - acetylbenzo-15 -crown -5 reacted with hydrazide under reflux condition to give eight new target products,and the single crystal of 4 ' -acetylbenzo-15-crown-5 2-naphthyloxy-acetylhydrazone obtained and the structure was resolved by X-ray diffraction method.The structure of all the products were characterized by IR, 'H NMR, and element analysis.The synthesis and crystal structure show the following result: (a) Introducing strong electron-withdrawing group to the benzene ring of hydrazidemade the reaction can't take place.(b) The yields of target compounds with electron-withdrawing group on the benzene ring of hydrazide are lower.(c) In the crystal structure of 4 ' -acetylbenzo-15-crown-5 2-naphthyloxy-acetylhydrazone, the naphthalene ring system is almost perpendicular to the crown ether ring. The substituents of the acylhydrazone group adopt a syn-anti conformation withrespect to the acylhydrazone moiety. In the packing diagram, every two molecules were connected into dimmers by centrosymmetrical intermolecular hydrogen bonds.3 Review on the anion recognition property of thioureaAccording to the number of thiourea group in a receptor, we classified the receptors and make a review on their anion recognition properties.4 The synthesis, characterization and anion recognition propertyThe 4' -acetylbenzo-15-crown-5 reacted with thiosemicarbazide at room temperature using concentrated hydrochloride (HCl)as catalyst to gave ten crowned thiosemicarbazone derivatives, nine of which are new compounds. The anion recognition property between receptors3b 3i 3j and F- Cl- Br- I- CH3COO- C3H7COO- were studied by UV-vis in CH3CN and 'HMR inThe result show:1:1 complexes formed between receptors 3b 3i 3j and F- CH3COO-C3H7COO-,the substituents on benzene ring of thiosemicarbazide moiety have a greateffect on their recognition ability.The stability constants of 3j with a strong electron-donoring para-OC2H5 on the benzene ring of thiosemicarbazide moiety are smaller than 3b without substituent and para-F substitued 3i. 3b 3iand 3j recognize anions in the similar selectivity order that F- C3H7COO- CH3COO-,however,they show no obvious recognition for Cl-, Br- and I-.