Coordination‐Induced Amplification of Birefringence and Nonlinear Optical Response in a Chiral Metal–Organic Framework

作者：Xinchao Wang, Hongyuan Sha, Zhaoxing Wang, Fei Wang, Shangda Li, Jian Zhang · 发表于：Angewandte Chemie International Edition · 年份：2025 · DOI：10.1002/anie.202516178 · 被引用次数：8 · 研究领域：Metal-Organic Frameworks: Synthesis and Applications、Nonlinear Optical Materials Studies、Nonlinear Optical Materials Research

Crystalline materials exhibiting programmable optical anisotropy are of great interest for advanced photonic applications but remain challenging. In this study, we introduce a coordination-driven approach that significantly enhances optical anisotropy by transforming a loosely packed molecular crystal (crystal-1) into a chiral metal-organic framework (MOF) (crystal-2). This structural transformation leads to a more than 20-fold increase in birefringence (Δn = 0.226 at 546 nm) and activates a measurable second-harmonic generation (SHG) activity. First-principles calculations suggest that the observed optical enhancement is driven by three main factors: coordination-driven enhancement of asymmetry, alignment of the π-conjugated framework, and anisotropic electron distribution. These findings highlight the potential of coordination polymerization as a versatile approach for designing hybrid optical materials with tailored anisotropy, providing a foundation for the development of MOF-based photonic devices.