Effects of Cocrystalline Subunits on the Supramolecular Chemistry of Me₁₀Q[5]: From Simple Inorganic Anions to Cluster Anions

Five supramolecular assemblies, formulated as {K2(H2O)3·[(Me10Q[5])@(H2O)0.5]}·Cl2 1, [K2(H2O)2·(Me10Q[5]@H2O)](ClO4)2·H2O 2, {K(H2O)·K(H2O)(SCN)Me10Q[5]}·(SCN)·H2O 3, [Na2(H2O)2K2(H2O)4(Me10Q[5])]·[Mo8O26] 4 and [Na2(H2O)2Rb2(H2O)4(Me10Q[5])]·[Mo8O26] 5, have been successfully isolated. Compounds 1−5 exhibit various structures based on the coordination of Me10Q[5] with alkali metals controlled by a series of anions, in which the anions play multiple roles of coordination, space-filling, charge-compensating etc. In the structure of compound 1, Me10Q[5] is capped by two [K(H2O)2]+ moieties through the carbonyl O atoms on the portals to form a bicapped unit. The bicapped Me10Q[5] units are interconnected to form a covalent bonded chain structure. Uncoordinated Cl− anions fill in the crystal lattice behaving as both counterions and space-filling agents. Compound 2 possesses isolated bicapped units comprised by Me10Q[5] and [K(H2O)]+ moieties, which are further linked via extensive hydrogen bonding interactions between the coordinated and uncoordinated water molecules into a supramolecular chain structure. The ClO4− anions are involved in the formation of hydrogen bonds with the coordinated aqua ligands located on the supramolecular chains. Compound 3 features an asymmetric bicapped Me10Q[5] unit due to the coordination of a [K(H2O)]+ or [K(H2O)(SCN)]+ on each portal of Me10Q[5]. The bicapped units in 3 are further extended into a supramolecular chain structure by hydrogen bonds between the coordinated water and carbonyl O atoms of Me10Q[5]. Moreover, uncoordinated SCN− anions are also observed in the crystal lattice. Compounds 4 and 5 are isomorphous and display interesting 3D network structures built by the interconnections of Me10Q[5], mixed alkali metal cations (Na+/K+ for 4 and Na+/Rb+ for 5), and [α-Mo8O26]4− cluster anions. In this study, the supramolecular assemblies of Me10Q[5] based solids show an anion dependent feature, which is systematically explored

Effects of Cocrystalline Subunits on the Supramolecular Chemistry of Me₁₀Q[5]: From Simple Inorganic Anions to Cluster Anions

Five supramolecular assemblies, formulated as {K2(H2O)3·[(Me10Q[5])@(H2O)0.5]}·Cl2 1, [K2(H2O)2·(Me10Q[5]@H2O)](ClO4)2·H2O 2, {K(H2O)·K(H2O)(SCN)Me10Q[5]}·(SCN)·H2O 3, [Na2(H2O)2K2(H2O)4(Me10Q[5])]·[Mo8O26] 4 and [Na2(H2O)2Rb2(H2O)4(Me10Q[5])]·[Mo8O26] 5, have been successfully isolated. Compounds 1−5 exhibit various structures based on the coordination of Me10Q[5] with alkali metals controlled by a series of anions, in which the anions play multiple roles of coordination, space-filling, charge-compensating etc. In the structure of compound 1, Me10Q[5] is capped by two [K(H2O)2]+ moieties through the carbonyl O atoms on the portals to form a bicapped unit. The bicapped Me10Q[5] units are interconnected to form a covalent bonded chain structure. Uncoordinated Cl− anions fill in the crystal lattice behaving as both counterions and space-filling agents. Compound 2 possesses isolated bicapped units comprised by Me10Q[5] and [K(H2O)]+ moieties, which are further linked via extensive hydrogen bonding interactions between the coordinated and uncoordinated water molecules into a supramolecular chain structure. The ClO4− anions are involved in the formation of hydrogen bonds with the coordinated aqua ligands located on the supramolecular chains. Compound 3 features an asymmetric bicapped Me10Q[5] unit due to the coordination of a [K(H2O)]+ or [K(H2O)(SCN)]+ on each portal of Me10Q[5]. The bicapped units in 3 are further extended into a supramolecular chain structure by hydrogen bonds between the coordinated water and carbonyl O atoms of Me10Q[5]. Moreover, uncoordinated SCN− anions are also observed in the crystal lattice. Compounds 4 and 5 are isomorphous and display interesting 3D network structures built by the interconnections of Me10Q[5], mixed alkali metal cations (Na+/K+ for 4 and Na+/Rb+ for 5), and [α-Mo8O26]4− cluster anions. In this study, the supramolecular assemblies of Me10Q[5] based solids show an anion dependent feature, which is systematically explored

Effects of Cocrystalline Subunits on the Supramolecular Chemistry of Me₁₀Q[5]: From Simple Inorganic Anions to Cluster Anions

Five supramolecular assemblies, formulated as {K2(H2O)3·[(Me10Q[5])@(H2O)0.5]}·Cl2 1, [K2(H2O)2·(Me10Q[5]@H2O)](ClO4)2·H2O 2, {K(H2O)·K(H2O)(SCN)Me10Q[5]}·(SCN)·H2O 3, [Na2(H2O)2K2(H2O)4(Me10Q[5])]·[Mo8O26] 4 and [Na2(H2O)2Rb2(H2O)4(Me10Q[5])]·[Mo8O26] 5, have been successfully isolated. Compounds 1−5 exhibit various structures based on the coordination of Me10Q[5] with alkali metals controlled by a series of anions, in which the anions play multiple roles of coordination, space-filling, charge-compensating etc. In the structure of compound 1, Me10Q[5] is capped by two [K(H2O)2]+ moieties through the carbonyl O atoms on the portals to form a bicapped unit. The bicapped Me10Q[5] units are interconnected to form a covalent bonded chain structure. Uncoordinated Cl− anions fill in the crystal lattice behaving as both counterions and space-filling agents. Compound 2 possesses isolated bicapped units comprised by Me10Q[5] and [K(H2O)]+ moieties, which are further linked via extensive hydrogen bonding interactions between the coordinated and uncoordinated water molecules into a supramolecular chain structure. The ClO4− anions are involved in the formation of hydrogen bonds with the coordinated aqua ligands located on the supramolecular chains. Compound 3 features an asymmetric bicapped Me10Q[5] unit due to the coordination of a [K(H2O)]+ or [K(H2O)(SCN)]+ on each portal of Me10Q[5]. The bicapped units in 3 are further extended into a supramolecular chain structure by hydrogen bonds between the coordinated water and carbonyl O atoms of Me10Q[5]. Moreover, uncoordinated SCN− anions are also observed in the crystal lattice. Compounds 4 and 5 are isomorphous and display interesting 3D network structures built by the interconnections of Me10Q[5], mixed alkali metal cations (Na+/K+ for 4 and Na+/Rb+ for 5), and [α-Mo8O26]4− cluster anions. In this study, the supramolecular assemblies of Me10Q[5] based solids show an anion dependent feature, which is systematically explored

Effects of Cocrystalline Subunits on the Supramolecular Chemistry of Me₁₀Q[5]: From Simple Inorganic Anions to Cluster Anions

Five supramolecular assemblies, formulated as {K2(H2O)3·[(Me10Q[5])@(H2O)0.5]}·Cl2 1, [K2(H2O)2·(Me10Q[5]@H2O)](ClO4)2·H2O 2, {K(H2O)·K(H2O)(SCN)Me10Q[5]}·(SCN)·H2O 3, [Na2(H2O)2K2(H2O)4(Me10Q[5])]·[Mo8O26] 4 and [Na2(H2O)2Rb2(H2O)4(Me10Q[5])]·[Mo8O26] 5, have been successfully isolated. Compounds 1−5 exhibit various structures based on the coordination of Me10Q[5] with alkali metals controlled by a series of anions, in which the anions play multiple roles of coordination, space-filling, charge-compensating etc. In the structure of compound 1, Me10Q[5] is capped by two [K(H2O)2]+ moieties through the carbonyl O atoms on the portals to form a bicapped unit. The bicapped Me10Q[5] units are interconnected to form a covalent bonded chain structure. Uncoordinated Cl− anions fill in the crystal lattice behaving as both counterions and space-filling agents. Compound 2 possesses isolated bicapped units comprised by Me10Q[5] and [K(H2O)]+ moieties, which are further linked via extensive hydrogen bonding interactions between the coordinated and uncoordinated water molecules into a supramolecular chain structure. The ClO4− anions are involved in the formation of hydrogen bonds with the coordinated aqua ligands located on the supramolecular chains. Compound 3 features an asymmetric bicapped Me10Q[5] unit due to the coordination of a [K(H2O)]+ or [K(H2O)(SCN)]+ on each portal of Me10Q[5]. The bicapped units in 3 are further extended into a supramolecular chain structure by hydrogen bonds between the coordinated water and carbonyl O atoms of Me10Q[5]. Moreover, uncoordinated SCN− anions are also observed in the crystal lattice. Compounds 4 and 5 are isomorphous and display interesting 3D network structures built by the interconnections of Me10Q[5], mixed alkali metal cations (Na+/K+ for 4 and Na+/Rb+ for 5), and [α-Mo8O26]4− cluster anions. In this study, the supramolecular assemblies of Me10Q[5] based solids show an anion dependent feature, which is systematically explored

Effects of Cocrystalline Subunits on the Supramolecular Chemistry of Me₁₀Q[5]: From Simple Inorganic Anions to Cluster Anions

Five supramolecular assemblies, formulated as {K2(H2O)3·[(Me10Q[5])@(H2O)0.5]}·Cl2 1, [K2(H2O)2·(Me10Q[5]@H2O)](ClO4)2·H2O 2, {K(H2O)·K(H2O)(SCN)Me10Q[5]}·(SCN)·H2O 3, [Na2(H2O)2K2(H2O)4(Me10Q[5])]·[Mo8O26] 4 and [Na2(H2O)2Rb2(H2O)4(Me10Q[5])]·[Mo8O26] 5, have been successfully isolated. Compounds 1−5 exhibit various structures based on the coordination of Me10Q[5] with alkali metals controlled by a series of anions, in which the anions play multiple roles of coordination, space-filling, charge-compensating etc. In the structure of compound 1, Me10Q[5] is capped by two [K(H2O)2]+ moieties through the carbonyl O atoms on the portals to form a bicapped unit. The bicapped Me10Q[5] units are interconnected to form a covalent bonded chain structure. Uncoordinated Cl− anions fill in the crystal lattice behaving as both counterions and space-filling agents. Compound 2 possesses isolated bicapped units comprised by Me10Q[5] and [K(H2O)]+ moieties, which are further linked via extensive hydrogen bonding interactions between the coordinated and uncoordinated water molecules into a supramolecular chain structure. The ClO4− anions are involved in the formation of hydrogen bonds with the coordinated aqua ligands located on the supramolecular chains. Compound 3 features an asymmetric bicapped Me10Q[5] unit due to the coordination of a [K(H2O)]+ or [K(H2O)(SCN)]+ on each portal of Me10Q[5]. The bicapped units in 3 are further extended into a supramolecular chain structure by hydrogen bonds between the coordinated water and carbonyl O atoms of Me10Q[5]. Moreover, uncoordinated SCN− anions are also observed in the crystal lattice. Compounds 4 and 5 are isomorphous and display interesting 3D network structures built by the interconnections of Me10Q[5], mixed alkali metal cations (Na+/K+ for 4 and Na+/Rb+ for 5), and [α-Mo8O26]4− cluster anions. In this study, the supramolecular assemblies of Me10Q[5] based solids show an anion dependent feature, which is systematically explored

Effects of Cocrystalline Subunits on the Supramolecular Chemistry of Me₁₀Q[5]: From Simple Inorganic Anions to Cluster Anions

Five supramolecular assemblies, formulated as {K2(H2O)3·[(Me10Q[5])@(H2O)0.5]}·Cl2 1, [K2(H2O)2·(Me10Q[5]@H2O)](ClO4)2·H2O 2, {K(H2O)·K(H2O)(SCN)Me10Q[5]}·(SCN)·H2O 3, [Na2(H2O)2K2(H2O)4(Me10Q[5])]·[Mo8O26] 4 and [Na2(H2O)2Rb2(H2O)4(Me10Q[5])]·[Mo8O26] 5, have been successfully isolated. Compounds 1−5 exhibit various structures based on the coordination of Me10Q[5] with alkali metals controlled by a series of anions, in which the anions play multiple roles of coordination, space-filling, charge-compensating etc. In the structure of compound 1, Me10Q[5] is capped by two [K(H2O)2]+ moieties through the carbonyl O atoms on the portals to form a bicapped unit. The bicapped Me10Q[5] units are interconnected to form a covalent bonded chain structure. Uncoordinated Cl− anions fill in the crystal lattice behaving as both counterions and space-filling agents. Compound 2 possesses isolated bicapped units comprised by Me10Q[5] and [K(H2O)]+ moieties, which are further linked via extensive hydrogen bonding interactions between the coordinated and uncoordinated water molecules into a supramolecular chain structure. The ClO4− anions are involved in the formation of hydrogen bonds with the coordinated aqua ligands located on the supramolecular chains. Compound 3 features an asymmetric bicapped Me10Q[5] unit due to the coordination of a [K(H2O)]+ or [K(H2O)(SCN)]+ on each portal of Me10Q[5]. The bicapped units in 3 are further extended into a supramolecular chain structure by hydrogen bonds between the coordinated water and carbonyl O atoms of Me10Q[5]. Moreover, uncoordinated SCN− anions are also observed in the crystal lattice. Compounds 4 and 5 are isomorphous and display interesting 3D network structures built by the interconnections of Me10Q[5], mixed alkali metal cations (Na+/K+ for 4 and Na+/Rb+ for 5), and [α-Mo8O26]4− cluster anions. In this study, the supramolecular assemblies of Me10Q[5] based solids show an anion dependent feature, which is systematically explored

Ultralow Pt Catalyst Loading Prepared by the Electroreduction of a Supramolecular Assembly for the Hydrogen Evolution Reaction

The hydrogen evolution reaction (HER) from the electrocatalysis of water splitting is the most promising approach to producing green and renewable hydrogen energy for sustainable development. The precious metal platinum is the best electrocatalyst for HER. However, its scarcity and high cost still hinder the large-scale application. It is highly desirable to fabricate efficient Pt electrocatalysts with low Pt loading. Herein, we report an efficient ultralow Pt-loading HER catalyst, which was obtained by the electroreduction of a preprepared supramolecular self-assembly. Utilizing the strong hydrogen bonding formation ability of macrocyclic cucurbit[8]uril (CB[8]), a porous supramolecule (CB[8]-[PtCl6]) composed of [PtCl6]2– and CB[8] is obtained as the HER catalyst precursor. By the electroreduction of the as-prepared supramolecular compound, Pt nanoparticles (NPs) protected by CB[8] (CB[8]-Pt) exhibit high catalytic activity and excellent long-term stability toward HER with ultralow Pt loading. CB[8]-Pt with a Pt loading of only 1.2 μg/cm2 presents 23 times higher HER activity than commercial Pt/C. Moreover, CB[8]-Pt shows excellent stability under 10 000-cycle cyclic voltammetry (CV) and at least 120 h for chronopotentiometry at 10 mA/cm2 in 0.5 M H2SO4, which greatly outperforms commercial Pt/C. This work provides a strategy for the rational design of ultralow-loading Pt catalysts with good activity and stability for hydrogen production

Porous Anionic, Cationic, and Neutral Metal-Carboxylate Frameworks Constructed from Flexible Tetrapodal Ligands: Syntheses, Structures, Ion-Exchanges, and Magnetic Properties

A series of coordination polymers with anionic, cationic, and neutral metal-carboxylate frameworks have been synthesized by using a flexible tetrapodal ligand tetrakis[4-(carboxyphenyl)oxamethyl] methane acid (H4X). The reactions between divalent transition-metal ions and H4X ligands gave [M3X2]·[NH2(CH3)2]2·8DMA (M = Co (1), Mn (2), Cd(3)) which have anionic metal-carboxylate frameworks with NH2(CH3)2+ cations filled in channels. The reactions of trivalent metal ions Y(III), Dy(III), and In(III) with H4X ligands afforded cationic metal-carboxylate frameworks [M3X2·(NO3)·(DMA)2·(H2O)]·5DMA·2H2O (M = Y(4), Dy(5)) and [In2X·(OH)2]·3DMA·6H2O (6) with the NO3− and OH− serving as counterions, respectively. Moreover, a neutral metal-carboxylate framework [Pb2X·(DMA)2]·2DMA (7) can also be isolated from reaction of Pb(II) and H4X ligands. The charged metal-carboxylate frameworks 1−5 have selectivity for specific counterions in the reaction system, and compounds 1 and 2 display ion-exchange behavior. Moreover, magnetic property measurements on compounds 1, 2, and 5 indicate that there exists weak antiferromagnetic interactions between magnetic centers in the three compounds

Porous Anionic, Cationic, and Neutral Metal-Carboxylate Frameworks Constructed from Flexible Tetrapodal Ligands: Syntheses, Structures, Ion-Exchanges, and Magnetic Properties

A series of coordination polymers with anionic, cationic, and neutral metal-carboxylate frameworks have been synthesized by using a flexible tetrapodal ligand tetrakis[4-(carboxyphenyl)oxamethyl] methane acid (H4X). The reactions between divalent transition-metal ions and H4X ligands gave [M3X2]·[NH2(CH3)2]2·8DMA (M = Co (1), Mn (2), Cd(3)) which have anionic metal-carboxylate frameworks with NH2(CH3)2+ cations filled in channels. The reactions of trivalent metal ions Y(III), Dy(III), and In(III) with H4X ligands afforded cationic metal-carboxylate frameworks [M3X2·(NO3)·(DMA)2·(H2O)]·5DMA·2H2O (M = Y(4), Dy(5)) and [In2X·(OH)2]·3DMA·6H2O (6) with the NO3− and OH− serving as counterions, respectively. Moreover, a neutral metal-carboxylate framework [Pb2X·(DMA)2]·2DMA (7) can also be isolated from reaction of Pb(II) and H4X ligands. The charged metal-carboxylate frameworks 1−5 have selectivity for specific counterions in the reaction system, and compounds 1 and 2 display ion-exchange behavior. Moreover, magnetic property measurements on compounds 1, 2, and 5 indicate that there exists weak antiferromagnetic interactions between magnetic centers in the three compounds

Stabilizing Sub-2-nm CuIr Nanoalloys with Cucurbit[6]uril for Oxygen Evolution Reaction in Strong Acid

Designing applicable high activity over long-term operation Ir-based alloy oxygen evolution reaction (OER) catalysts plays an important role in the development of the water-splitting process under acidic conditions. Herein, we report that cucurbit[6]­uril-supported copper–iridium alloy (CB[6]-CuIr) hybrid with the enhancement of activity and stability for OER. The CB[6]-Cu0.33Ir0.67 shows a current density of 11.68 mA/cm2, which is 8.4 times greater than that of Ir black at η = 280 mV. CB[6]-Cu0.33Ir0.67 exhibits superior stability without activity loss after 10 h of continuous operation at 10 mA/cm2, while the CuIr alloy stabilized by carbon or polyvinylpyrrolidone is deactivated within 1 and 4 h, respectively. X-ray absorption fine structure (XAFS) and electron energy loss spectroscopy (EELS) confirm the interaction between the Cu0.33Ir0.67 alloy and CB[6] that can avoid the formation of dissoluble CuIr oxides. This is the first report on using CB[6] to make binary nanoalloys, providing insights into the application of the supramolecules in functionalizing nanomaterials