Self-assembly of four supramolecular architectures: From 0-D to 2-D frameworks based on an unsymmetrical N-heterocyclic ligand
作者:Xiangru Meng、Sizeng Jin、Hongwei Hou、Chenxia Du、Seik Weng Ng
DOI:10.1016/j.ica.2008.07.027
日期:2009.4
The computed results of the free bmt ligand reveal that the Mulliken charges of N18 and N23 are -0.391 and -0.275, respectively, and both of them have higher distributions in the highest occupied molecular orbital (HOMO) of the free ligand bmt. Based on the above results, four new complexes, [Cu(bmt)(4)] center dot (Cl)(2) center dot 4H(2)O (1), [Cu(bmt)(2)(NCS)(2)] (2), [Cu(bmt)Cl](n) (3), and [Ag(bmt)(NO3)](n) (4) [bmt = 1-((benzotriazol-1-yl)methyl)-1-H-1,2,4-triazole], have been synthesized and characterized by single-crystal X-ray diffraction. Complex 1 reveals a 0-D structure and further forms a 1-D supramolecular structure by intermolecular pi-pi interactions. Complex 2 also displays a 0-D structure, but it extends to 2-D supramolecular networks through weak Cu center dot center dot center dot S interactions. However, complex 3 features a 1-D wavy chain structure bearing weak Cu center dot center dot center dot Cl interactions to form 2-D networks. Complex 4 exhibits a 2-D netlike structure. The experimental results display that the coordination modes of the ligand bmt are corresponded with the computed results. Furthermore, the. fluorescence emissions of complexes 3 and 4 in a solid state at room temperature may be assigned to ligand-to-metal charge-transfer (LMCT). (C) 2008 Published by Elsevier B. V.