Ag4L2 Nanocage as a Building Unit toward the Construction of Silver Metal Strings

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• 作者：Jing-Yun Wu ; Yu-Fang Lin ; Chuan-Hung Chuang ; Tien-Wen Tseng ; Yuh-Sheng Wen ; Kuang-Lieh Lu
• 刊名：Inorganic Chemistry
• 出版年：2008
• 出版时间：November 17, 2008
• 年：2008
• 卷：47
• 期：22
• 页码：10349-10356
• 全文大小：431K
• 年卷期：v.47,no.22(November 17, 2008)
• ISSN：1520-510X

文摘

Self-assembly of AgNO₃ with the semirigid tetratopic ligands 1,2,4,5-tetrakis(benzoimidazol-1-ylmethyl)benzene (TBim) and 1,2,4,5-tetrakis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene (TDMBim) afforded compounds [Ag₄(μ₄-TBim)₂(μ₂-η²-NO₃)₂](NO₃)₂·¹/₂CH₂Cl₂·2CH₃OH (1μ¹/₂CH₂Cl₂·2CH₃OH) and [(NO₃⁻)⊂{Ag₄(μ₄-TDMBim)₂}][Ag(NO₃)₂](NO₃)₂·CH₂Cl₂·CH₃OH·4H₂O (2·CH₂Cl₂·CH₃OH·4H₂O), respectively. The structures of 1 and 2 were characterized by single-crystal X-ray diffraction analysis. Both compounds adopt a M₄L₂-type tetragonal metalloprismatic cage structure, [Ag₄(μ₄-L)₂]⁴⁺, with strong intramolecular silver−silver contacts. Compound 1 is a discrete species, while compound 2 is a novel infinite chainlike supramolecular array involving silver metal strings assembled from a [Ag₄(μ₄-L)₂]⁴⁺ nanocage and silver linkages. Thermogravimetric analyses of 1·¹/₂CH₂Cl₂·2CH₃OH and 2·CH₃OH·4H₂O indicate that the Ag₄L₂-cage structures of 1 and 2 both are thermally stable up to 330 °C. Results from an in situ ¹H NMR study of AgNO₃ and TDMBim in different molar ratios unambiguously revealed the successive self-organization process, in which self-organization of the molecular cage takes place initially followed by crystallization of the corresponding supramolecular arrays with silver metal strings.