[Ag(NH3)2]2SO4: A Strategy for the Coordination of Cationic Moieties to Design Nonlinear Optical Materials

Over recent decades, guided by the anionic group theory of nonlinear optical (NLO) materials, rational design strategies have been primarily focused on anionic moieties; consequently, structural modification and design of cationic moieties have long been neglected. Herein, we report a strategy for t...

Full description

Saved in:
Bibliographic Details
Published in:Angewandte Chemie International Edition 2021-09, Vol.60 (39), p.21216-21220
Main Authors: Yang, Yi‐Chang, Liu, Xin, Lu, Jing, Wu, Li‐Ming, Chen, Ling
Format: Article
Language:English
Subjects:
Ammonia
Anisotropy
Birefringence
cationic moiety coordination
Cations
Coordination
Crystal optics
Crystal structure
Design
Design modifications
Dipoles
Electromagnetic radiation
Group theory
Incident light
noncentrosymmetric
nonlinear optical materials
Nonlinear optics
Optical materials
Optical properties
Optics
Phase matching
Potassium phosphate
Potassium phosphates
second harmonic generation
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Over recent decades, guided by the anionic group theory of nonlinear optical (NLO) materials, rational design strategies have been primarily focused on anionic moieties; consequently, structural modification and design of cationic moieties have long been neglected. Herein, we report a strategy for the coordination of cationic moieties that substantially enhances the optical properties of NLO materials. For an example with well‐known crystal structure, [Ag(NH3)2]2SO4, we demonstrate that the coordination of the Ag+ cation by the neutral ligand drives the formation of a noncentrosymmetric tetragonal P4‾ 21c structure as a positive uniaxial crystal. The bending of the [Ag(NH3)2]+ cationic moiety parallel to the z‐axis generates an anisotropic arrangement of the dipoles, i.e., a dipole of 0.12 D along the z‐direction, yet zero dipole in the xy‐plane, which interacts anisotropically with the incident light oscillating electromagnetic wave, leading to optical anisotropy with a large birefringence. The incident beam of 589.3 nm normal to the (110) crystal plane measures Δnobv.=0.08, and [Ag(NH3)2]2SO4 also exhibits a phase‐matching NLO response 1.4 times that of KH2PO4 (KDP) (obv. 1.4×KDP @1064 nm; cal. d36=1.50 pm V−1). A new strategy for the coordination of cationic moieties offers a new possibility for the rational design and property modification of functional ionic materials, particularly NLO materials. As demonstrated by [Ag(NH3)2]2SO4 and Ag2SO4, the exceptional enhancements of the linear birefringence and nonlinear SHG properties are attributed to the unique [Ag(NH3)2]+ cation moiety.
ISSN:1433-7851
1521-3773
DOI:10.1002/anie.202107780