Macrocyclic, dinuclear zine(II)-directed self-assembly with pyridine, 2,2′-bipyridine and 2-methylquinoline:: μ2-OH bridging bi-macrocyclic complexes and hydrogen-bond-supported donor-acceptor complexes

Two macrocyclic dinuclear zinc(ii) complexes (la and 1b) have been self-assembled in the presence of pyridine and 2,2'-bipyridine, respectively, to form mu(2)-OH-bridged bimacrocycles with a Zn4O4 cavity through coordination bonding. The X-ray structural analysis reveals that both compounds {2a: [Zn4L2a(OH)(2)](2)(ClO4)(2); 2b: [Zn4L2b(OH)(2)](2)(ClO4)(2)) have an open-mouthed sandwich-like structure with pi-pi interactions between parts of two phenyl rings to strengthen two hydroxyl groups connecting the metal atoms in the same direction of the macrocycle. Furthermore, nonclassical C-(HCl)-Cl-... intermolecular interactions have been observed in the crystal of 2b. In addition, the reaction of la with quinoline derivatives has yielded novel hydrogen-bond-supported donor-acceptor complexes {3a: [Zn2La(H2O)(2)(C10H9N)(2)](ClO4)(2)} The crystallographic study of the complex containing 2-methylquinoline indicates that two 2-methylquinoline molecules are linked to two coordinating water molecules above and below the macrocyclic framework through O-(HN)-N-... hydrogen bonds. The 2-methylquinoline plane interacts in a face-to-face fashion with the phenyl ring of adjacent macrocyclic frameworks, forming an ordered arrangement where one macrocycle and two 2-methylquinolines are arrayed alternately with almost the same separation. The interplanar distance mentioned before is ca. 3.6 Angstrom. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).