POS5-1192
Isomorphic Organic Nonlinear Optical Crystals by Space-Filling Strategy for Efficient Terahertz Wave Generation
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Seungmin Kim (Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea)
Co-Author(s)
Abstract
Designing organic nonlinear optical (NLO) crystals with non-centrosymmetric molecular arrangements remains a significant challenge in crystal engineering. Even subtle molecular modifications frequently change the crystal packing, making it difficult to preserve the non-centrosymmetric crystal structure. Herein, we present an anion space-filling engineering strategy to develop isomorphic organic NLO salt crystals. A highly nonlinear optical quinolinium cationic chromophore was paired with a series of substituted benzenesulfonate anions possessing different van der Waals volumes and polarities. Only anions with appropriate steric and electronic characteristics preserved the isomorphic non-centrosymmetric crystal structure, highlighting the importance of balanced substituent selection in the crystal design. This isomorphic crystal structures enabled systematic evaluation of the anion space-filling effect by minimizing structural variations of molecular packing in the crystalline state.
The bulky substituents effectively filled the void volume without disrupting the crystal structure, strengthening intermolecular interactions and increasing the crystal density. The denser crystal packing is expected to restrict collective molecular vibrations, thereby suppressing molecular phonon modes responsible for THz self-absorption. These findings demonstrate that anion space-filling engineering provides a rational crystal engineering strategy for developing high performance organic NLO crystals toward efficient THz wave generation.
The bulky substituents effectively filled the void volume without disrupting the crystal structure, strengthening intermolecular interactions and increasing the crystal density. The denser crystal packing is expected to restrict collective molecular vibrations, thereby suppressing molecular phonon modes responsible for THz self-absorption. These findings demonstrate that anion space-filling engineering provides a rational crystal engineering strategy for developing high performance organic NLO crystals toward efficient THz wave generation.
