Aggregation-Induced Emission of Curcuminoid-BF2 Complex for Phosphor-Converted Red Light-Emitting Diode.

The incorporation of difluoroboron ß-diketonate and tetraphenylethene under a facile Knoevenagel condensation reaction afforded one new D-π-A-π-D complex TCBF with high aggregation-induced emission (AIE) activity. The TCBF film can maintain a high photocurrent after long-term (500 min) photoelectronic measurements. The successful fabrication of a red LED device makes it a promising candidate for high-performance solid-state lighting.

Synthesis, Crystal Structure, and Photophysical Properties of Bromothiophene-Functionalized BF2-Curcuminoid as a Versatile Building Block.

A novel bromothiophene-functionalized BF2-curcuminoid (BTC-BF2) is synthesized by Knoevenagel condensation reaction. The structure of BTC-BF2 is determined by 1H-nuclear magnetic resonance (1H NMR), 13C-nuclear magnetic resonance (13C NMR), and high-resolution mass spectrometry (HRMS). Moreover, a nearly coplanar single crystal structure is successfully obtained and form a mesh structure through intermolecular multiple C─H···F hydrogen bond interactions. As expected, as-prepared BTC-BF2 exhibits solvent-dependent photophysical properties in solvents with different polarity and an intense red solid-state fluorescence. Density functional theory calculations further verify the relationships between its intrinsic electronic features and the photophysical properties. For its potential application aspect, BTC-BF2 shows a certain ability to generate singlet oxygen under irradiation with 530 nm green light. Moreover, BTC-BF2 can be utilized as versatile building block to construct novel far-red or NIR BF2-curcuminoid complexes for widely biological applications.

Crystallization and single molecule magnetic behavior of quadruple-stranded helicates: tuning the anisotropic axes.

It has been successfully proven that the bis-ß-diketone ligands with proper lengths and flexibility are essential for the construction of multiple-stranded helicates, where two Dy3+ centers in subtly different environments allow the tuning of the anisotropic axes. Based on our previous work, we have designed a flexible bis-ß-diketone ligand BTT (BTT = 3,3''-bis(4,4,4-trifluoro-1,3-dioxobutyl)-m-terphenyl), which is successfully utilized to construct quadruple-stranded helicates with the formula of [C6H16N]2[Ln2(BTT)4]·2CH2Cl2·4CH3OH [Ln = Ce (1), Dy (2)]. Structural analysis indicates that they crystallize in the tetragonal space group P4/n, and each Ln3+ center is chelated by four diketonate moieties from four ligands, giving rise to a dinuclear quadruple-stranded helicate. Magnetic measurements show that 2 displays single molecular magnet behavior under an applied DC field of 2000 Oe. Further investigations indicate that the anisotropic axes of the Dy3+ centers can be tuned depending on the bis-ß-diketonate ligands used to assemble the Dy helicates.