Tailor-Made Zinc Uranyl Diphosphonates from Layered to Framework Structures
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- 作者：Hong-Yue Wu ; Weiting Yang ; Zhong-Ming Sun
- 刊名：Crystal Growth & Design
- 出版年：2012
- 出版时间：September 5, 2012
- 年：2012
- 卷：12
- 期：9
- 页码：4669-4675
- 全文大小：451K
- 年卷期：v.12,no.9(September 5, 2012)
- ISSN：1528-7505
文摘
Hydrothermal reactions of zinc uranyl acetate and 1-hydroxyethylidenediphosphonic acid (H4L) with 1,10-phenanthroline (phen), 2,2鈥?bipyridine (bipy), 1H-benzo[d]imidazole (bi), or 1-phenyl-1H-imidazole (pi) resulted in the formation of four new zinc uranyl compounds, namely, [Zn2(phen)2(UO2)2(L)2(H2O)3]路3H2O (ZnUP-1), Zn2(bipy)2(UO2)2(L)2(H2O)2 (ZnUP-2), (Hbi)[Zn0.5(UO2)2(L)(H2L)(H2O)3]路3H2O (ZnUP-3), and (Hpi)[Zn(UO2)2(H2O)4(L)(HL)]路H2O (ZnUP-4). These four structures all comprise uranyl diphosphonate layers formed by UO7 pentagonal bipyramids and PO3C tetrahedra. Such layers are further connected by Zn-centered polyhedra by sharing oxygens from phosphonate groups. For ZnUP-1 and ZnUP-2, the zinc atoms are terminally coordinated by phen and bipy molecules, respectively, resulting in two-dimensional (2-D) hybrid materials. In ZnUP-3 and ZnUP-4, the uranyl phosphonate layers are joined together by Zn鈥揙 polyhedra forming three-dimensional (3-D) frameworks. The structures of ZnUP-3 and ZnUP-4 contain large channels along the a-axis with apertures around 3.4 脳 13.3 and 4.4 脳 12.2 脜2, respectively. Protonated templates exist in the channels, filling the space and compensating the negative charge of the anionic frameworks. Photoluminescent studies reveal that ZnUP-1 and ZnUP-2 exhibit the characteristic vibronically coupled charge-transfer based UO22+ emission.