Noncomplexed Cucurbituril-Mediated Structural Evolution of Layered Uranyl Terephthalate Compounds

Abstract

Template synthesis is one of the most feasible ways to explore new uranyl compounds with intriguing structures and properties.Here we demonstrate the preparation of six novel "sandwichlike" uranyl coordination polymers (UCPs) based on two-dimensional uranylterephthalate acid (H 2 TP) networks using CBn (n = 5, 6, 8) as template ligands in the presence of different cations (Na + , K + , Cs + , orof layered uranyl-TP networks with the complex of CB5 and s o d i u m c a t i o n s a s t e m p l a t e l i g a n d s . I n c o m p o u n d 2 ([(UO 2 ) 2 (TP) 3 ] 2 (CB6)(H 2 O) 10 ), CB6 located between uranyl-TP networks contacts them by π−π interactions and hydrogen bonds. Compound 3 ([(UO 2 ) 2 (TP) 3 ] 2 [Na 2 (H 2 O) 10 (CB6)]) is the same as compound 2 except for sodium cations bonding with CB6. Similarly in compound 4 ([(UO 2 ) 2 (TP) 3 ][Cs(H 2 O) 3 (CB6)]), CB6 is a capsulelike structure capped with two cesium cations and interacts with uranyl-TP networks through π−π and C−H•••π interactions. Compound 5 ([(UO 2 ) 2 (TP) 3 (HCOO) consists of both templates of CB6 and CB5 in which each CB5 is capped with one potassium cation while the H 2 N(CH 3 ) 2 + cation is held at CB6 portals. In compound 6), CB8 ligands are connected by cesium cations to form a triangle motif and are further located between the uranyl-TP networks as template agents. All of the 2D layered structures with free CBn or cation-anchored CBn intercalate into the laminates of uranyl-terephthalate and shows a cucurbituril-mediated structural evolution. The regulating role of CBn as structure-directing template agents for the construction of layered UCPs through outer-surface interactions with layers of uranyl terephthalate is demonstrated, especially for the case of CB6 with contractive interlayer spacing.

Unveiling the new function of uranyl molecular clusters as fluorometric sensors for UV and X-ray dosimetry

“…Although HCOOH was not added as a reactant during the synthesis of 2 , hydrolyzation of DMF generated HCOO − anions, which were subsequently incorporated into the structure of 2 . 34,35 The structure of 1 has been reported by Cahill et al and Brown et al , while 2 is new and obtained in this work. 36,37 Single crystal X-ray diffraction analyses revealed that 1 and 2 crystallize in the P 2 1 / n and P 1̄ space groups, respectively (Table S1†).…”

Emergence of Thorium-Based Polyoxo Clusters as a Platform for Selective X-ray Dosimetry

“…In situ hydrolysis of DMF was involved in both reactions, and the different pH values gave rise to different amounts of formate groups incorporated in Th-bppCOO-1 and Th-bppCOO-2. 23,24 The phase purities of bulk samples of Th-bppCOO-1 and Th-bppCOO-2 were confirmed by powder X-ray diffraction (PXRD; Figure S1). Thermogravimetric analysis (TGA) demonstrated that Th-bppCOO-1 and Th-bppCOO-2 were thermally stable up to approximately 100 and 140 °C, respectively (Figure S2).…”

“…Th-bppCOO-1 and Th-bppCOO-2 were prepared via solvothermal reactions between Th­(NO 3 ) 4 and bppCOOH with the addition of concentrated HCl and CH 3 COOH, respectively, in mixed DMF/H 2 O (1:1) solutions at 100 °C for 24 h. The yields of Th-bppCOO-1 and Th-bppCOO-2 were calculated to be 51.9% and 55.9%, respectively, based on thorium. In situ hydrolysis of DMF was involved in both reactions, and the different pH values gave rise to different amounts of formate groups incorporated in Th-bppCOO-1 and Th-bppCOO-2 . , The phase purities of bulk samples of Th-bppCOO-1 and Th-bppCOO-2 were confirmed by powder X-ray diffraction (PXRD; Figure S1). Thermogravimetric analysis (TGA) demonstrated that Th-bppCOO-1 and Th-bppCOO-2 were thermally stable up to approximately 100 and 140 °C, respectively (Figure S2).…”