Photoluminescent 3D Lanthanide鈥揙rganic Frameworks Based on 2,5-Dioxo-1,4-piperazinylbis(methylphosphonic) Acid Formed via in Situ Cyclodehydration of Glyphosates

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• 作者：Yunshan Zhou ; Yan Guo ; Sheng Xu ; Lijuan Zhang ; Waqar Ahmad ; Zonghai Shi
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：June 3, 2013
• 年：2013
• 卷：52
• 期：11
• 页码：6338-6345
• 全文大小：411K
• 年卷期：v.52,no.11(June 3, 2013)
• ISSN：1520-510X

文摘

Hydrothermal reactions of lanthanide nitrates with glyphosate have resulted three new isostructural 3D lanthanide鈥搊rganic frameworks, Ln(NO₃)(H₂L) [Ln = Eu (1), Tb (2), Gd (3); H₄L = 2,5-dioxo-1,4-piperazinylbis(methylphosphonic) acid], with good yields, where H₄L as a new ligand was formed via in situ cyclodehydration of original ligand glyphosates during the hydrothermal reaction. The compounds were thoroughly characterized by IR, UV鈥搗is, elemental analysis, single-crystal X-ray diffraction analysis, powder X-ray diffraction analysis, and thermogravimetric/differential thermal analysis (TG-DTA). Three compounds display 3D 6,6-connected open frameworks with 4¹³路6² topology possessing 1D channels in which NO₃^{鈥?/sup> anions act as troglodytes by chelating Ln3+ centers. The TG-DTA study of the compounds showed remarkable thermal stability up to 380 掳C. Under room temperature UV-light irradiation, the Eu3+ and Tb3+ compounds showed the corresponding characteristic Ln3+ intra 4fn emission peaks. The triplet energy level (21882 cm鈥?) of the ligand (H₄L) was determined from the emission spectrum of its Gd3+ compound at 77 K. The emission lifetimes (1.54 ms of 5D₀ for compound 1 and 1.98 ms of 5D₄ for compound 2) and absolute emission quantum yields (10.1% for compound 1 and 5.9% for compound 2) were also determined.}