Applying reticular synthesis to the design of Cu-based MOFs with mechanically interlocked linkers

The concept of“robust dynamics”describes the incorporation of mechanically interlocked molecules(MIMs)into metal-organic framework(MOF)materials such that large amplitude motions(e.g.,rotation or translation of a macrocycle)can occur inside the free volume pore of the MOF.To aid in the preparation of such materials,reticular synthesis was used herein to design rigid molecular building blocks with predetermined ordered structures starting from the well-known MOF NOTT-101.New linkers were synthesized that have a T-shape,based on a triphenylene tetra-carboxylate strut,and their incorporation into Cu(II)-based MOFs was investigated.The single-crystal structures of three new MOFs,UWCM-12(fof),β-UWCM-13(loz),UWCM-14(lil),with naked T-shaped linkers were determined;β-UWCM-13 is the first reported example of the loz topology.A fourth MOF,UWDM-14(lil)is analogous to UWCM-14(lil)but contains a[2]rotaxane linker.Variable-temperature,²H solid-state NMR was used to probe the dynamics of a 24-membered macrocycle threaded onto the MOF skeleton.     

Enhancing Phosphorescence and Electrophosphorescence Efficiency of Cyclometalated Pt(II) Compounds with Triarylboron

A synthetic strategy for the preparation of cyclometalated platinum(II) acetylacetonate (acac) complexes functionalized with triarylboron is achieved. This method is used to synthesize a series of triarylboron‐functionalized phosphorescent Pt(acac) compounds, which are characterized by NMR spectroscopy, X‐ray crystallography, and theoretical calculations. These complexes exhibit a range of bright phosphorescent colors spanning the green to red region of the visible spectrum (λ_max = ～520–650 nm) in solution and the solid state. Functionalization with a triarylboron group leads to significant enhancement in quantum yield for several of these complexes relative to the non‐borylated Pt(II) parent chromophores, which may be attributed to the increased mixing of ¹MLCT and ³LC states. The phosphorescent enhancement, electron transport capabilities, and steric bulkiness offered by the triarylboron group can be used to significantly enhance the performance of electrophosphorescent devices based on Pt(II) emitters. A high efficiency green electrophosphorescent device is fabricated with a maximum external quantum efficiency of 8.9%, luminance efficiency of 34.5 cd A^?1, and power efficiency of 29.8 lm W^?1, giving significantly improved performance over control devices in which the Pt(II) emitter lacks the boron functionality.