RESUMO
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 â¼10%. 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).
RESUMO
We describe one-pot synthesis of stable doubly N-fused expanded dibenziporphyrinoids using readily available precursors under acid-catalyzed conditions. The doubly N-fused expanded dibenziporphyrinoids have been synthesized by adopting an inversion followed by fusion strategy. The studies showed that the dibenziporphyrinoids undergo mono fusion initially, but due to the high stability of doubly fused dibenziporphyrinoids, the monofused macrocycles undergo further fusion to form doubly fused dibenziporphyrinoids. The mono fusion and double fusion in these dibenziporphyrinoids were established by X-ray crystallography.
RESUMO
We report the synthesis of first examples of BF(2) and B(OR)(2) complexes of oxasmaragdyrin, the expanded core-modified porphyrin, in decent yields under very simple reaction conditions at room temperature. The boron complexation of oxasmaragdyrin alters the electronic properties of the macrocycle significantly as evident by various spectroscopic techniques. Our preliminary studies indicated that the B(OH)(2)-smaragdyrin complex can act as a selective neutral fluoride ion sensor.