Uranyl−Organic Frameworks with 1,2,3,4-Butanetetracarboxylate and 1,2,3,4-Cyclobutanetetracarboxylate Ligands
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- 作者：Pierre Thué ; ry ; Bernardo Masci
- 刊名：Crystal Growth & Design
- 出版年：2008
- 出版时间：September 3, 2008
- 年：2008
- 卷：8
- 期：9
- 页码：3430-3436
- 全文大小：403K
- 年卷期：v.8,no.9(September 3, 2008)
- ISSN：1528-7505
文摘
The reaction of uranyl nitrate with 1,2,3,4-butanetetracarboxylic acid (H4BTC) and 1,2,3,4-cyclobutanetetracarboxylic acid (H4CBTC) under hydrothermal conditions gives various two- and three-dimensional frameworks. The complex [(UO2)2(BTC)(H2O)4]·4H2O (1) is a (4,4) grid in which the BTC4− ligands act as rectangular nodes and the uranyl ions as divergent, side-defining nodes. Complexes [(UO2)2(CBTC)(H2O)2]·2H2O (2) and [(UO2)2(CBTC)(H2O)2]·H2O (3), with the ligand in the cis,trans,cis form, present two types of three-dimensional architectures, with narrow channels formed in complex 2 only. In complex 4, [H3O]2[(UO2)5(CBTC)3(H2O)6], the ligand is in the noncentrosymmetric trans,trans,trans form, which assumes a saddle shape. This peculiar geometry of the ligand results in the formation of two types of subunits: 4:4 (metal/ligand) metallacycles and 8:12 cubic boxes, which are connected to one another to form a cubic lattice containing large channels. This latter result shows that the same geometric considerations which have permitted the synthesis of uranyl-based molecular metallamacrocycles and boxes can be used for the design of porous three-dimensional frameworks based on analogous motifs.