| The nitrogen atoms in azacrown ethers have a specific role in coordination with metalions. The structures of these macrocyclic ligands and their complexes are similar with someimportant bioenzymes in body, which have their potential application in the biologicalmedicine, biomimetic chemistry, cell membrane transmission, the metal enzyme simulationand self-assembly of supramolecular and so on. In order to investigate the coordinationproperties of different macrocyclic ligands with metal ions, crown ether L1 and three novelnitrogen-pivot benzo-aza-lariat crown ethers (HL2, H2L3, L4) prepared by us for the first timewere used for study. Five metal complexes [CdL1(NO3)2] (1), [Cd(HL2)(NO3)]·NO3 (2),[Cu(HL2) (NO3)]·NO3·EtOH (3), [CuL3]·CHCl3 (4) and [ZnL4]·(NO3)2·H2O (5) which all havenever been reported previously were synthesized.L1 = 1,4,11,14-tetraoxa-5,6:19,20-dibenzo-8,17-diazacycloeicosane;HL2 = 8-(5-nitro-2-hydroxybenzyl)-1,4,11,14-tetraoxa-5,6:19,20-dibenzo-8,17-diazacycloeicosane;H2L3 = 8,17-bis(5-nitro-2-hydroxybenzyl)-1,4,11,14-tetraoxa-5,6:19,20-dibenzo-8,17-diazacycloeicosan;L4 = 8,17-bis(methylene-2-pyridyl)-1,4,11,14-tetraoxa-5,6:19,20-dibenzo-8,17-diazacycloeicosane.The crystal structures have been determined by single-crystal X-ray diffraction.Cadmium atoms in compounds 1 and 2 show an eight-coordinated distorted square-antiprismatic geometry and a seven-coordinated distorted pentagonal bipyramidal geometryrespectively. Copper atoms in compounds 3 and 4 show a six-coordinated distorted threeprismatic geometry and a four-coordinated distorted tetrahedral geometry respectively. Zincatom in compound 5 shows a six-coordinated distorted octahedral geometry.
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