[C(NH2)3]Y(HCOO)4: Constructing 3D Framework for Guanidine-Based UV Nonlinear Optical Crystals with Good Performance

Jiayin Tang; Xin Wen; Huili Zhang; Yuchen Yan; Jindong Chen; Shihui Ma; Min Luo; Chensheng Lin; Ning Ye; Guang Peng

doi:10.1021/acs.inorgchem.5c01629

[C(NH₂)₃]Y(HCOO)₄: Constructing 3D Framework for Guanidine-Based UV Nonlinear Optical Crystals with Good Performance

Inorg Chem. 2025 Jun 16;64(23):11323-11328. doi: 10.1021/acs.inorgchem.5c01629. Epub 2025 Jun 2.

Authors

Jiayin Tang¹, Xin Wen², Huili Zhang¹, Yuchen Yan¹, Jindong Chen¹, Shihui Ma¹, Min Luo³, Chensheng Lin³, Ning Ye¹, Guang Peng¹

Affiliations

¹ State Key Laboratory of Crystal Materials, Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystal, Tianjin University of Technology, Tianjin 300384, China.
² State Key Laboratory of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan 250100, China.
³ Key Laboratory of Functional Crystals and Devices, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.

PMID: 40452556
DOI: 10.1021/acs.inorgchem.5c01629

Abstract

The guanidine group, [C(NH₂)₃]⁺, is a promising π-conjugated unit for nonlinear optical (NLO) materials. However, its saturated amino coordination typically leads to weak hydrogen bond interaction and zero-dimensional structures, limiting the stability and mechanical strength. Herein, we propose a design strategy that constructs a non-centrosymmetric (NCS) three-dimensional (3D) framework for [C(NH₂)₃]⁺ by utilizing (HCOO)^- and rare-earth cations and successfully synthesizes a novel 3D guanidine-based compound, [C(NH₂)₃]Y(HCOO)₄, which not only effectively immobilizes the [C(NH₂)₃]⁺ but also induces an NCS arrangement. This crystal exhibits a strong second-harmonic generation response of 1.7 × KH₂PO₄, a short UV cutoff edge of 236 nm, an appropriate birefringence of 0.099@546 nm, and good thermal stability, fulfilling critical requirements for UV NLO applications. This work provides a new strategy for developing high-performance guanidine-based UV NLO materials.