American Chemical Society
cg060076s_si_003.cif (12.43 kB)

Anion-Directed Assembly of Macrocycle and Helix

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posted on 2006-06-07, 00:00 authored by Xuanjun Zhang, Xiao-Ping Zhou, Dan Li
Self-assembly of the flexible ligand N,N‘-bis(3-pyridylmethyl)thiourea (bpt) with ZnCl2 and CdCl2 in the absence and presence of KSCN yielded a short series of novel complexes (14) with macrocyclic, helical, double-helical, and 1D polymeric structures. Different metal ions, hydrogen bonds, and counteranions play significant roles in the final crystal structures. The NCS- anion was found to favor the formation of helical structures, whereas the Cl- anion favored macrocycle formation in the present system. Photoluminescence (PL) measurement results revealed that complex 2 (Zn(bpt)(SCN)2) with a helical structure exhibits enhanced emissions compared to those of the ligand and other complexes. The anion-directed assembly as well as the interesting emissions may provide useful information for further design of metal−organic compounds with novel structures and properties.