Syntheses and Structures of Uranyl Ethylenediphosphonates: From Layers to Elliptical Nanochannels
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- 作者：Tao Tian ; Weiting Yang ; Hao Wang ; Song Dang ; Qing-Jiang Pan ; Zhong-Ming Sun
- 刊名：Inorganic Chemistry
- 出版年：2013
- 出版时间：June 17, 2013
- 年：2013
- 卷：52
- 期：12
- 页码：7100-7106
- 全文大小：439K
- 年卷期：v.52,no.12(June 17, 2013)
- ISSN：1520-510X
文摘
A family of uranium diphosphonates have been hydrothermally synthesized through the reaction of ethylenediphosphonic acid (EDP, H4L) and uranyl nitrate/zinc uranyl acetate in the presence of organic templates, such as tetraethyl ammonium (NEt4+), 4,4鈥?bipyridine (bipy), and 1,10-phenanthroline (phen). The UO22+ in UO2(H2O)(H2L)(EDP-U1) is equatorially five-coordinated by four phosphonate groups and one aqua ligand, forming a pentagonal bipyramid. Each EDP ligand is doubly protonated and chelates three UO22+, resulting in a layered structure. Compounds (NEt4)2(UO2)3(HL)2(H2L)路4H2O (EDP-U2) and (H2bipy)UO2L (EDP-U3) have the same layered structure in which NEt4+ and protonated bipy fill in the uranyl鈥損hosphonate interlayers, respectively, and play a role to balance the negative charges. Different from that in EDP-U1, the UO22+ exists in the form of a UO6 tetragonal bipyramid and is surrounded by four different EDP ligands in EDP-U2 and EDP-U3. (Hphen)2(UO2)2(H2L)3 (EDP-U4) features a three-dimensional framework structure with large elliptical channels along the c axis (1.3 脳 1.1 nm2). Monoprotonated phen molecules fill in these channels and hold together through strong 蟺路路路蟺 interactions. All of the four compounds have been characterized by IR and photoluminescent spectroscopy. Their characteristic emissions have been attributed as transition properties of uranyl cations. The ion-exchange study indicates that [Co(en)3]3+ could partially replace the protonated phen molecules.