A Straightforward Strategy toward Large BN-Embedded π‑Systems: Synthesis, Structure, and Optoelectronic Properties of Extended BN Heterosuperbenzenes

A straightforward strategy has been used to construct large BN-embedded π-systems simply from azaacenes. BN heterosuperbenzene derivatives, the largest BN heteroaromatics to date, have been synthesized in three steps. The molecules exhibit curved π-surfaces, showing two different conformations which are self-organized into a sandwich structure and further packed into a π-stacking column. The assembled microribbons exhibit good charge transport properties and photoconductivity, representing an important step toward the optoelectronic applications of BN-embedded aromatics

Alkylene-Chain Effect on Microwire Growth and Crystal Packing of π‑Moieties

We developed a facile approach to modulate molecular arrangement through dimerizing of π-moieties and tuning alkylene-bridge length. Dimers of fluoranthene-fused imide (<b>DFAI-Cn</b>s) with various lengths of alkylene chains were synthesized by a Diels–Alder reaction followed by decarbonylation. <b>DFAI-C3</b> and <b>DFAI-C5</b> with odd-carbon alkylene chains display stronger one-dimensional growing tendency and better crystallinity than those with even-carbon alkylene chains. Microwires of dimers with odd-carbon alkylene chains were successfully obtained, and their molecular packing was analyzed by transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). Systematic investigation of their single crystal packing showed that alkylene chains with different lengths produced two kinds of molecular configurations. The V-shaped molecular configuration was observed from <b>DFAI-C3</b> and <b>DFAI-C5</b> with odd-carbon alkylene chains; however, the Z-shaped one was observed from <b>DFAI-C4</b>, <b>DFAI-C6</b>, and <b>DFAI-C12</b> with even-carbon alkylene chains. Accordingly, we attributed the diverse microstructures and crystallinity of the dimers to their distinct molecular configurations in single crystals. In addition, a computational method was employed to demonstrate the weak intermolecular interactions in these dimers. Our investigation indicates that the introduction of bridging alkylene chains is an effective approach to modulate microwire growth and crystal packing of π-systems in solid state

Alkylene-Chain Effect on Microwire Growth and Crystal Packing of π‑Moieties

We developed a facile approach to modulate molecular arrangement through dimerizing of π-moieties and tuning alkylene-bridge length. Dimers of fluoranthene-fused imide (<b>DFAI-Cn</b>s) with various lengths of alkylene chains were synthesized by a Diels–Alder reaction followed by decarbonylation. <b>DFAI-C3</b> and <b>DFAI-C5</b> with odd-carbon alkylene chains display stronger one-dimensional growing tendency and better crystallinity than those with even-carbon alkylene chains. Microwires of dimers with odd-carbon alkylene chains were successfully obtained, and their molecular packing was analyzed by transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). Systematic investigation of their single crystal packing showed that alkylene chains with different lengths produced two kinds of molecular configurations. The V-shaped molecular configuration was observed from <b>DFAI-C3</b> and <b>DFAI-C5</b> with odd-carbon alkylene chains; however, the Z-shaped one was observed from <b>DFAI-C4</b>, <b>DFAI-C6</b>, and <b>DFAI-C12</b> with even-carbon alkylene chains. Accordingly, we attributed the diverse microstructures and crystallinity of the dimers to their distinct molecular configurations in single crystals. In addition, a computational method was employed to demonstrate the weak intermolecular interactions in these dimers. Our investigation indicates that the introduction of bridging alkylene chains is an effective approach to modulate microwire growth and crystal packing of π-systems in solid state