N‐Doped Nonalternant Nanoribbons with Excellent Nonlinear Optical Performance

Abstract Two novel N ‐doped nonalternant nanoribbons ( NNNR‐1 and NNNR‐2 ) featuring multiple fused N ‐heterocycles and bulky solubilizing groups were prepared via bottom‐up solution synthesis. NNNR‐2 achieves a total molecular length of 33.8 Å, which represents the longest soluble N ‐doped nonalternant nanoribbon reported to date. The pentagon subunits and doping of N atoms in NNNR‐1 and NNNR‐2 have successfully regulated their electronic properties, achieving high electron affinity and good chemical stability enabled by the nonalternant conjugation and electronic effects. When applied a laser pulse of 532 nm, the 13‐rings nanoribbon NNNR‐2 shows outstanding nonlinear optical (NLO) responses, with the nonlinear extinction coefficient of 374 cm GW −1 , much higher than those of NNNR‐1 (96 cm GW −1 ) and the well‐known NLO material C 60 (153 cm GW −1 ). Our findings indicate that the N ‐doping of nonalternant nanoribbons is an effective strategy to access another type of excellent material system for high‐performance NLO applications, which can be extended to construct numerous heteroatom‐doped nonalternant nanoribbons with fine‐tunable electronic properties.