Related Experiment Video
Updated: Oct 25, 2026
Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Halogen-Driven Modulation of Structural Symmetry and Optical Properties in Hybrid Copper(I) Halides: Tunable
Man Xu1, Hai-Ping Xu1, Ji-Fen Guo1
1Yunnan Key Laboratory of Electromagnetic Material and Devices, School of Materials and Energy, Yunnan University, Kunming650500, P. R. China.
Abstract:
Organic-inorganic hybrid Cu(I)-based halides have become a promising class of optoelectronic materials due to their adjustable structures, low cost, and easy solution processing. To explore the dual regulatory effect of halide ions on structures and optical properties, two copper(I) halide compounds, namely (BuTPP)CuCl2 (1) and (BuTPP)CuBr2 (2) [BuTPP+ = (1-butyl)triphenylphosphonium, C22H24P+], were synthesized. Halogen substitution induces a symmetry transformation from non-centrosymmetric (NCS) 1 to centrosymmetric 2. The former exhibits phase-matchable second-harmonic-generation (SHG) intensity of 0.8 × KDP. Meanwhile, the birefringence is nearly doubly enhanced from 1 to 2 with halogen substitution. Moreover, halide engineering effectively tunes the luminescence color, viz., 1 emits yellow-green light, whereas 2 displays bluish-green emission. This study realizes the synchronous modulation of structural symmetry, SHG performance, birefringence, and photoluminescence via halogen substitution, which offers a powerful route to develop multifunctional optical hybrid materials.
Related Concept Videos
03:24Hybridization of Atomic Orbitals I
01:26Variables Affecting Phosphorescence and Fluorescence
02:46Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
02:52Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...