Affiliation:
1. Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University) Department of Chemistry Fuzhou University Fuzhou 350108 China
2. College of Chemistry and Material Science Longyan University Longyan 364012 China
3. School of Physical Science and Technology Soochow University Suzhou 215006 China
4. College of Materials Science and Engineering Huaqiao University Xiamen 361021 China
Abstract
AbstractThis study presents the design, synthesis, and comprehensive characterization of a novel series of D‐π‐A type malononitrile‐derived chromophores, BTC‐1–BTC‐4. Combining various spectroscopic techniques, nonlinear Z‐scan measurements, and quantum chemical calculations, we revealed the intricate relationship between nonlinear optical properties and the interplay of molecular structure, intramolecular charge transfer (ICT), and dipole moments (μ). Our experimental and computational findings corroborate that the polarization degree in the ground state, the charge separation in the excited state and twisted intramolecular charge transfer (TICT) collectively dictate the nonlinear optical properties of the compounds. Notably, BTC‐1 exhibits an exceptional nonlinear absorption coefficient β value (2×10−8 m W−1), attributed to its optimized charge transfer efficiency and pronounced degree of charge separation. Our findings provide actionable insights for the rational design of high‐performance organic Nonlinear optics (NLO) materials with potential applications in advanced photonic devices.