It is well known that [CO₃]²⁻ groups are one kind of most promising structural groups for nonlinear optical (NLO) materials in the ultraviolet (UV) and visible spectral region, because their π-conjugated planar triangular configuration is favorable to generate excellent optical properties. There is still no review on NLO materials with [CO₃]²⁻ groups and the corresponding structure-property relationships. In this review, we systematically summerize NLO materials with π-conjugated [CO₃]²⁻ triangles and attempt to demonstrate the underlying structure-property relationships between the microscopic arrangement of [CO₃]²⁻ triangles and macroscopic optical properties. There are some interesting findings disclosed. Firstly, the cation-centered MO_xF₂ (M = cations of +2 or +3 oxidation numbers, x = 4, 5, 6, 8) polyhedra in carbonates play a significant role in the orientation of [CO₃]²⁻ groups, which make the major contribution to NLO coefficients. More concretely, the different radii of M cations results in different arrangement of [CO₃]²⁻ groups. Secondly, in contrast to the notable anionic group theory, some cations, especially the cations with stereoactive lone-pair electrons, make additional considerable contributions to the overall NLO effect. We believe that this review will shed helpful insights on the rational design and synthesis of new NLO materials of carbonates.

众所周知，[CO ₃ ] ²⁻基团是在紫外（UV）和可见光谱区域中的非线性光学（NLO）材料最有前途的一种结构基团，因为它们的π共轭平面三角形构型易于产生优良的光学性能。带有[CO ₃ ] ²⁻基团和相应的结构-性质关系的NLO材料仍然没有评论。在这篇综述中，我们系统地总结了具有π共轭[CO ₃ ] ²⁻三角形的NLO材料，并试图证明[CO ₃ ] ²⁻的微观排列之间的潜在结构性质关系。三角形和宏观光学性质。公开了一些有趣的发现。首先，碳酸盐中以阳离子为中心的MO _x F ₂（M =氧化数为+2或+3的阳离子，x = 4、5、6、8）在[CO ₃ ] ²⁻的取向中起重要作用组，这对NLO系数起主要作用。更具体地说，M阳离子的半径不同会导致[CO ₃ ] ^2−的排列不同组。其次，与著名的阴离子基团理论相反，某些阳离子，特别是具有立体活性孤对电子的阳离子，对整个NLO效应做出了其他重要贡献。我们相信，这项审查将对新型碳纳米管非水合材料的合理设计和合成提供有益的见解。