Ligand-to-Ligand Charge Transfer Induced Red-Shifted Room Temperature Phosphorescence in Metal-Organic Frameworks.

Research on room temperature phosphorescence (RTP) of metal-organic frameworks (MOFs) has been rapidly developed in recent years. However, it is still challenging to realize long-wavelength RTP (>580 nm). In this article, a new strategy is proposed to achieve the red-shifted RTP through constructing dual-ligand MOFs.

Ligand Meta-Anchoring Strategy in Metal-Organic Frameworks for Remarkable Promotion of Quantum Yields.

Aggregation is a conventional method to enhance the quantum yields (QYs) of pure organic luminophores due to the restriction of intramolecular motions (RIM). However, how to realize RIM in metal-organic frameworks (MOFs) is still unclear and challenging. In this work, the ligand meta-anchoring strategy is first proposed and proved to be an effective and systematic approach to restrict the intramolecular motions of MOFs for the QY improvement.

Synthesis of 1-(β-coumarinyl)-1-(β-indolyl)trifluoroethanols through regioselective Friedel-Crafts alkylation of indoles with β-(trifluoroacetyl)coumarins catalyzed by Sc(OTf).

A highly efficient Friedel-Crafts alkylation of indole derivatives with β-(trifluoroacetyl)coumarins using Sc(OTf) as a catalyst has been developed, which gives regioselective 1,2-adducts to afford 1-(β-coumarinyl)-1-(β-indolyl)trifluoroethanols. A series of tertiary trifluoroethanols containing different indole and coumarin groups were synthesized in moderate to excellent yields (up to 95%) in the presence of 5 mol% catalyst in a short time (only 2 minutes at least). A mechanism of the reaction, in which the trace amount of water plays the role of proton transfer in catalyzing circulation was proposed and confirmed.