Carbohydrate-attached fullerene derivative for selective localization in ordered carbohydrate-block-poly(3-hexylthiophene) nanodomains.

A carbohydrate-based fullerene derivative (AcMal7-C61) is designed, synthesized and applied to a lamellar-forming high-χ block copolymer system, poly(3-hexylthiophene)-block-peracetylated maltoheptaose (P3HT-b-AcMal7), to actualize an ordered donor/acceptor (D/A) network. A well-defined D/A lamellar structure of the P3HT-b-AcMal7:AcMal7-C61 blend with sub-10 nm domain features is achieved upon thermal annealing. The AcMal7-C61 molecules are localized in the phase-separated AcMal7 nanodomains without causing the formation of fullerene crystals while maintaining the lamellar morphology up to 1:0.5 (D:A) blending ratio. The cross-sectional TEM observation and GISAXS measurement reveals that the P3HT-b-AcMal7 tends to spontaneously organize into lamellar structures oriented perpendicular to the film surface at the air/film interface while the domain orientation at the bottom interface depends on the nature of the substrate.

A Pure-Red Doublet Emission with 90 % Quantum Yield: Stable, Colorless, Iodinated Triphenylmethane Solid.

Red luminescence is found in off-white tris(iodoperchlorophenyl)methane (3I-PTMH ) crystals which is characterized by a high photoluminescence quantum yield (PLQY 91 %) and color purity (CIE coordinates 0.66, 0.34). The emission originates from the doublet excited state of the neutral radical 3I-PTMR , which is spontaneously formed and becomes embedded in the 3I-PTMH matrix. The radical defect can also be deliberately introduced into 3I-PTMH crystals which maintain a high PLQY with up to 4 % radical concentration. The immobilized iodinated radical demonstrates excellent photostability (estimated half-life >1 year under continuous irradiation) and intriguing luminescent lifetime (69 ns). TD-DFT calculations demonstrate that electron-donating iodine atoms accelerate the radiative transition while the rigid halogen-bonded matrix suppresses the nonradiative decay.

A Two-Dimensional Poly(azatriangulene) Covalent Organic Framework with Semiconducting and Paramagnetic States.

The black crystalline (aza)triangulene-based covalent organic framework TANG-COF was synthesized from its trinitro-TANG precursor via a one-pot, two-step reaction involving Pd-catalyzed hydrogenation and polycondensation with an aromatic dialdehyde. High crystallinity and permanent porosity of the layered two-dimensional (2D) structure were established. The rigid, electron-rich trioxaazatriangulene (TANG) building block enables strong π-electron interactions manifested in broad absorptions across the visible and NIR regions (Eg ≈ 1.2 eV). The high HOMO energy of TANG-COF (-4.8 eV) enables facile p doping, resulting in electrical conductivity of up to 10-2 S/cm and room-temperature paramagnetic behavior with a spin concentration of ∼10%. DFT calculations reveal dispersion of the highest occupied band both within the 2D polymer layers (0.28 eV) and along their π-stacked direction (0.95 eV).