Visible-light-promoted selenylation/cyclization of -(1-alkynyl) benzoates to access seleno-substituted isocoumarins.

A simple and efficient method to access 4-selenyl-isocoumarin derivatives through visible-light-promoted selenylation/cyclization of -(1-alkynyl) benzoates has been developed. This transformation is performed under mild conditions and has the advantages of functional group tolerance and broad substrate scope.

Visible-Light-Promoted Selenylation/Cyclization of -Alkynyl Benzylazides/-Propargyl Arylazides: Synthesis of Seleno-Substituted Isoquinolines and Quinolines.

A simple and efficient visible-light-promoted selenylation/cyclization of -alkynyl benzylazides/-propargyl arylazides have been realized for the practical synthesis of seleno-substituted isoquinolines and quinolines. This strategy provides the synthesis of valuable seleno-substituted isoquinoline and quinoline derivatives via the construction of one C(sp2)-Se bond and one C-N bond within one process.

Epitaxial Growth of γ-Cyclodextrin-Containing Metal-Organic Frameworks Based on a Host-Guest Strategy.

A class of metal-organic frameworks (MOFs)-namely CD-MOFs-obtained from natural products has been grown in an epitaxial fashion as films on the surfaces of glass substrates, which are modified with self-assembled monolayers (SAMs) of γ-cyclodextrin (γ-CD) molecules. The SAMs are created by host-guest complexation of γ-CD molecules with surface-functionalized pyrene units. The CD-MOF films have continuous polycrystalline morphology with a structurally out-of-plane ( c-axial) orientation, covering an area of several square millimeters, with a thickness of ∼2 μm.

Toward a Charged Homo[2]catenane Employing Diazaperopyrenium Homophilic Recognition.

An octacationic diazaperopyrenium (DAPP)-based homo[2]catenane (DAPPHC), wherein no fewer than eight positive charges are associated within a mechanically interlocked molecule, has been produced in 30% yield under ambient conditions as a result of favorable homophilic interactions, reflecting a delicate balance between strong π-π interactions and the destabilizing penalty arising from Coulombic repulsions between DAPP units. This DAPPHC catenane is composed of two identical mechanically interlocked tetracationic cyclophanes, namely DAPPBox, each of which contains one DAPP unit and one extended viologen (ExBIPY) unit, linked together by two p-xylylene bridges. The solid-state structure of the homo[2]catenane demonstrates how homophilic interactions play an important role in the formation of DAPPHC, in which the mean ring planes of the two DAPPBox cyclophanes are oriented at about 60° with respect to each other, with a centroid-to-centroid separation of 3.

Intramolecular Energy and Electron Transfer within a Diazaperopyrenium-Based Cyclophane.

Molecules capable of performing highly efficient energy transfer and ultrafast photoinduced electron transfer in well-defined multichromophoric structures are indispensable to the development of artificial photofunctional systems. Herein, we report on the synthesis, characterization, and photophysical properties of a rationally designed multichromophoric tetracationic cyclophane, DAPPBox, containing a diazaperopyrenium (DAPP) unit and an extended viologen (ExBIPY) unit, which are linked together by two p-xylylene bridges. Both H NMR spectroscopy and single-crystal X-ray diffraction analysis confirm the formation of an asymmetric, rigid, box-like cyclophane, DAPPBox.

Design and Synthesis of a Water-Stable Anionic Uranium-Based Metal-Organic Framework (MOF) with Ultra Large Pores.

Ionic metal-organic frameworks (MOFs) are a subclass of porous materials that have the ability to incorporate different charged species in confined nanospace by ion-exchange. To date, however, very few examples combining mesoporosity and water stability have been realized in ionic MOF chemistry. Herein, we report the rational design and synthesis of a water-stable anionic mesoporous MOF based on uranium and featuring tbo-type topology.