Hydrogen‐Bond‐Directed Modular Assembly of Polar Chains for Rational Construction of UV Nonlinear Optical Crystals

Abstract

AbstractNon‐centrosymmetric (NCS) materials underpin a host of emerging technologies—from high‐power lasers to optical communications and sensors—yet their targeted design remains a formidable challenge. Herein, we introduce a “Hydrogen‐Bond‐Directed Modular Assembly” strategy for the rational construction of ultraviolet (UV) nonlinear optical (NLO) crystals. In this strategy, programmable hydrogen‐bonding schemes serve as a predictive handle to propagate local asymmetry into a macroscopic polar network. Using an explicit modular design algorithm, we selected three building units—C3H3O4−, C4H5O4−, and C(NH2)3+—and assembled them into two one‐dimensional polar chain modules, [C(NH2)3C3H3O4]∞ and [C(NH2)3C4H5O4]∞. These modules crystallize as two new UV NLO materials, C(NH2)3C3H3O4 and C(NH2)3C4H5O4, which exhibit excellent linear and nonlinear optical properties. By shifting the synthetic focus from serendipitous screening to hydrogen‐bond‐guided, module‐level engineering, our strategy establishes a predictive framework for the a priori design of NCS structures with tailored properties.