The condensation of π-conjugated units: a new paradigm for designing high-performance optical crystals.

Saved in:
Bibliographic Details
Title: The condensation of π-conjugated units: a new paradigm for designing high-performance optical crystals.
Authors: Jia, Hangwei1 (AUTHOR), Chen, Bailin1,2 (AUTHOR), Zhang, Fangfang1,2 (AUTHOR), Hou, Xueling1,2 (AUTHOR) xlhou@ms.xjb.ac.cn, Pan, Shilie1,2 (AUTHOR) slpan@ms.xjb.ac.cn
Source: Chemical Society Reviews. 5/26/2026, Vol. 55 Issue 10, p5838-5866. 29p.
Subjects: Birefringence, Nonlinear optical materials, Far ultraviolet radiation, Molecular polarizability, Crystal optics, Electron delocalization, Band gaps
Abstract: The π-conjugated units condensation paradigm (π-CUCP) is defined as the formation of larger π-conjugated groups through the chemical bonding of small units possessing π-conjugated structures. Its core objective is to significantly enhance the macroscopic optical properties (birefringence or SHG response) by strengthening electron delocalization, increasing structural anisotropy, and optimizing band structures. Planar π-conjugated units like [BO3]3−–[B3O6]3− or [C(NH2)3]+–[C3N6H7]+ serve as representative π-CUCP. π-CUCP effectively improves the microscopic optical properties of molecular structural units, such as polarizability anisotropy and hyperpolarizability, thereby enhancing the macroscopic optical performance of nonlinear optical and birefringent materials. This review systematically summarizes representative and emerging compounds of π-CUCP, primarily covering approximately 112 representative examples across three major categories: borates, carboxyl-C–N heterocycles and amino-C–N heterocycles. Further research indicates that incorporating π-CUCP into deep-ultraviolet optical compounds enhances birefringence and maintains relatively wide bandgaps, enabling phase matching within the short-wavelength spectrum. The introduction of π-CUCP into ultraviolet and deep ultraviolet birefringent optical materials provides a feasible and effective approach to enhance the birefringence. Through the integration of multiple exploratory examples, this paper proposes an innovative design strategy to elevate the birefringent properties of the compounds, paving a new direction for the development of high-performance optical materials. [ABSTRACT FROM AUTHOR]
Copyright of Chemical Society Reviews is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:The π-conjugated units condensation paradigm (π-CUCP) is defined as the formation of larger π-conjugated groups through the chemical bonding of small units possessing π-conjugated structures. Its core objective is to significantly enhance the macroscopic optical properties (birefringence or SHG response) by strengthening electron delocalization, increasing structural anisotropy, and optimizing band structures. Planar π-conjugated units like [BO3]3−–[B3O6]3− or [C(NH2)3]+–[C3N6H7]+ serve as representative π-CUCP. π-CUCP effectively improves the microscopic optical properties of molecular structural units, such as polarizability anisotropy and hyperpolarizability, thereby enhancing the macroscopic optical performance of nonlinear optical and birefringent materials. This review systematically summarizes representative and emerging compounds of π-CUCP, primarily covering approximately 112 representative examples across three major categories: borates, carboxyl-C–N heterocycles and amino-C–N heterocycles. Further research indicates that incorporating π-CUCP into deep-ultraviolet optical compounds enhances birefringence and maintains relatively wide bandgaps, enabling phase matching within the short-wavelength spectrum. The introduction of π-CUCP into ultraviolet and deep ultraviolet birefringent optical materials provides a feasible and effective approach to enhance the birefringence. Through the integration of multiple exploratory examples, this paper proposes an innovative design strategy to elevate the birefringent properties of the compounds, paving a new direction for the development of high-performance optical materials. [ABSTRACT FROM AUTHOR]
ISSN:03060012
DOI:10.1039/d5cs01327e