A Redox Responsive, Fluorescent Supramolecular Metallohydrogel Consists of Nanofibers with Single-Molecule Width

The integration of a tripeptide derivative, which is a versatile self-assembly motif, with a ruthenium­(II)­tris­(bipyridine) complex affords the first supramolecular metallo-hydrogelator that not only self assembles in water to form a hydrogel but also exhibits gel–sol transition upon oxidation of the metal center. Surprisingly, the incorporation of the metal complex in the hydrogelator results in the nanofibers, formed by the self-assembly of the hydrogelator in water, to have the width of a single molecule of the hydrogelator. These results illustrate that metal complexes, besides being able to impart rich optical, electronic, redox, or magnetic properties to supramolecular hydrogels, also offer a unique geometrical control to prearrange the self-assembly motif prior to self-assembling. The use of metal complexes to modulate the dimensionality of intermolecular interactions may also help elucidate the interactions of the molecular nanofibers with other molecules, thus facilitating the development of supramolecular hydrogel materials for a wide range of applications

Solvothermal Synthesis of a Stable Coordination Polymer with Copper-I−Copper-II Dimer Units: [Cu₄{1,4-C₆H₄(COO)₂}₃(4,4‘-bipy)₂]<i>_n</i>

Solvothermal Synthesis of a Stable Coordination Polymer with Copper-I−Copper-II Dimer Units:  [Cu4{1,4-C6H4(COO)2}3(4,4‘-bipy)2]n</i

Solvothermal Synthesis of a Stable Coordination Polymer with Copper-I−Copper-II Dimer Units: [Cu₄{1,4-C₆H₄(COO)₂}₃(4,4‘-bipy)₂]<i>_n</i>

Solvothermal Synthesis of a Stable Coordination Polymer with Copper-I−Copper-II Dimer Units:  [Cu4{1,4-C6H4(COO)2}3(4,4‘-bipy)2]n</i

Atomic Bonding between Metal and Graphene

To understand structural and chemical properties of metal–graphene composites, it is crucial to unveil the chemical bonding along the interface. We provide direct experimental evidence of atomic bonding between typical metal nano structures and graphene, agreeing well with density functional theory studies. Single Cr atoms are located in the valleys of a zigzag edge, and few-atom ensembles preferentially form atomic chains by self-assembly. Low migration barriers lead to rich dynamics of metal atoms and clusters under electron irradiation. We demonstrate no electron-instigated interaction between Cr clusters and pristine graphene, though Cr has been reported to be highly reactive to graphene. The metal-mediated etching is a dynamic effect between metal clusters and pre-existing defects. The resolved atomic configurations of typical nano metal structures on graphene offer insight into modeling and simulations on properties of metal-decorated graphene for both catalysis and future carbon-based electronics

Atomic Bonding between Metal and Graphene

To understand structural and chemical properties of metal–graphene composites, it is crucial to unveil the chemical bonding along the interface. We provide direct experimental evidence of atomic bonding between typical metal nano structures and graphene, agreeing well with density functional theory studies. Single Cr atoms are located in the valleys of a zigzag edge, and few-atom ensembles preferentially form atomic chains by self-assembly. Low migration barriers lead to rich dynamics of metal atoms and clusters under electron irradiation. We demonstrate no electron-instigated interaction between Cr clusters and pristine graphene, though Cr has been reported to be highly reactive to graphene. The metal-mediated etching is a dynamic effect between metal clusters and pre-existing defects. The resolved atomic configurations of typical nano metal structures on graphene offer insight into modeling and simulations on properties of metal-decorated graphene for both catalysis and future carbon-based electronics

Atomic Bonding between Metal and Graphene

To understand structural and chemical properties of metal–graphene composites, it is crucial to unveil the chemical bonding along the interface. We provide direct experimental evidence of atomic bonding between typical metal nano structures and graphene, agreeing well with density functional theory studies. Single Cr atoms are located in the valleys of a zigzag edge, and few-atom ensembles preferentially form atomic chains by self-assembly. Low migration barriers lead to rich dynamics of metal atoms and clusters under electron irradiation. We demonstrate no electron-instigated interaction between Cr clusters and pristine graphene, though Cr has been reported to be highly reactive to graphene. The metal-mediated etching is a dynamic effect between metal clusters and pre-existing defects. The resolved atomic configurations of typical nano metal structures on graphene offer insight into modeling and simulations on properties of metal-decorated graphene for both catalysis and future carbon-based electronics