π-Expansion of 2,3,6,7-Tetraazanaphthalene with Two Embedded Heptagons: Highly Twisted Structure and Lone-Pair/π* Interaction in the Crystal

Abstract

Synthesis and characterization of doubly diphenylene-fused 2,3,6,7-tetraazanaphthalene 1 are described. Single-crystal X-ray diffraction analysis showed the highly twisted structure of 1 with a degree of twisting of 13.0°/Å, which is one of the largest values for a π-system. In the crystal, molecules of 1 formed an orthogonal one-dimensional column with π-stacking of diphenylene moieties and a short intermolecular C···N distance due to lone-pair/π* interaction, which is a rare example of lone-pair/π* interaction in a supramolecular assembly.

Recent advances in versatile pyridazine-cored materials: principles, applications, and challenges

“…This review calls for more efforts to enrich versatile PDs for high-performance materials beyond bioactive pharmaceutical drugs and pesticides. 49,147 For the sake of more and better functional PD-ringbased materials, herein, the general strategy can be explored by combining the previous studies and interesting results with practical synthetic methodologies (Scheme 7), 50,106,[148][149][150][151][152][153][154][155][156] theoretical calculations, 129,[157][158][159][160][161] aza-quantity effect and azaregioisomerism, 159,160 and supramolecular strategies, 29,[162][163][164][165] the serendipitously discovered or well-designed of PD-based materials possess huge application prospects in the fields of optoelectronics, chromism, fluorescence probes, and energy materials. The unceasing breakthroughs in catalysis, 9,45,115,154,166,167 magnetic complexes, 155,168 molecular rotators (Fig.…”

Color-tunable emissive heptagon-embedded polycyclic aromatic dicarboximides

“…1). 7 Polycyclic aromatic dicarboximides (PADIs) are one of the most important classes of organic materials that are widely used as n-type semiconductors in organic optoelectronics, 8 theranostic agents in biomedical applications, 9 and building blocks in supramolecular chemistry. 10 Among these, functionalized PADIs, especially naphthalene and perylenemonoimides, are the most investigated PADIs as these peri-functionalized PADIs with electron donating groups can create donor-p-acceptor or push-pull systems.…”