Uranyl-Lanthanide Heterometallic Complexes with Cucurbit[6]uril and Perrhenate Ligands

Abstract

The reaction of uranyl and lanthanide nitrates with cucurbit[6]uril (CB6) in the presence of perrhenic acid and under hydrothermal conditions yields the novel heterometallic uranyl-lanthanide molecular complexes [UO2Ln(CB6)(ReO4)2(NO3)(H2O)7](ReO4)2 (Ln = Sm, Eu, Gd, Lu). Both metal cations are bound to carbonyl groups of the same CB6 portal, one for UO2(2+) and two for Ln3+. The uranium atom is also bound to one monodentate perrhenate ion and three aquo ligands, while the lanthanide is bound to one monodentate perrhenate and one nitrate ions, and four aquo ligands. Not only are these complexes rare examples of ReO4(-) bonding to f element ions, but the perrhenate bound to Ln is included in the CB6 cavity, thus providing the first case of inclusion of a tetrahedral oxoanion in this macrocycle.

Simple Coordination Complexes of Cucurbit[n]urils with Metal Ions

“…These reactions have been carried out in the presence of various species, which could behave as structural inducers: examples include sebacic acid, L-(+)-tartaric acid, citric acid, and [55], Ho [55], Er [55,56], Yb [56]; c Ln = Dy [57], Ho [57], Er [57]; d Ln = La [57]; e Ln = Pr [56,57], Nd [56]; and f Ln = La [57], Pr [57], Dy [57]; the tetrahedral Ag + centers are shown above and below the top and bottom portals of the Q[6] sandwich structure second metal salts. For example, Thuéry characterized a series of Q [6]/Ln 3+ -based molecular capsules (Ln = Ce 3+ , Pr 3+ ) and molecular bowls (Ln = Yb 3+ , Lu 3+ ) including a perrhenate anion in perrhenic acid (Fig.…”

“…Each U1 atom is bound to two carbonyl atoms from two Q [6] Fig. 2.22c) [57]. Initial attempts by Thuéry to prepare heteronuclear uranyl-lanthanide Q [6] complexes were unsuccessful [27] [58].…”

One-Dimensional Coordination Polymers of Lanthanide Cations to Cucurbit[7]uril Built Using a Range of Tetrachloride Transition-Metal Dianion Structure Inducers

“…Cucurbit[n]urils(Q[n]s) [9][10][11][12][13][14] consist of a rigid hydrophobic cavity of low polarity, accessible through two open polar portals rimmed with carbonyl groups, which can interact with various metal ions [15][16][17][18][19][20][21][22][23][24][25][26], or their complexes [27][28][29][30][31][32][33][34][35][36][37][38][39][40] or clusters [41][42][43][44][45][46][47][48][49][50] [53]. In recent years, there has been a trend towards introducing an organic or inorganic species into the metal-Q[n] systems as a "structure inducer" or trigger, since the properties, structural novelties, and functionalities of the resulting coordination polymers have often exceeded those observed in the absence of such agents.…”

“…In recent years, there has been a trend towards introducing an organic or inorganic species into the metal-Q[n] systems as a "structure inducer" or trigger, since the properties, structural novelties, and functionalities of the resulting coordination polymers have often exceeded those observed in the absence of such agents. Following on from Fedin's work [30,32], Thuéry focused on the Q[n] complexation of lanthanides and actinides and demonstrated the formation of a series of lanthanide-Q[n] and uranyl-Q[n] supramolecular assemblies in the presence of added organic ligands [34][35][36][37]. Since a novel potassium-Q [5] supramolecular network was first prepared in the presence of p-hydroxybenzoic acid [60], coordination of metal ions to Q[n]s in the presence of various organic molecules has been extensively studied in our laboratory, and a strategy for inorganic or organic molecule-induced coordination polymers of metal ions to Q[n]s has gradually been established.…”

Direct coordination of metal ions to cucurbit[n]urils

“…Cucurbit[n]urils (Q[n]) readily include different organic molecules to form various hostguest inclusion complexes, pseudorotaxanes, catenanes, and molecular knots [25][26][27][28][29][30][31][32][33][34]. In addition, they also readily coordinate to metal ions, such as alkali and alkaline earth metal ions [35][36][37][38][39][40], transition metal ions [41][42][43], lanthanide metal ions, uranyl ions and their complexes [44][45][46][47][48][49][50][51] or clusters [52][53][54][55][56][57][58][59][60][61]. These interactions result in the formation of various exclusion complexes, one-dimensional (1D) or poly-dimensional architectures and frameworks.…”