Related Experiment Video
Updated: Mar 10, 2026
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Ultralong Afterglow in Zero- and One-Dimensional Cd(II) Halide Complexes with Differential Arrangement of
Yun-Lan Li1, Guang-Huang Zhang1, Ru-Yan Li2
1Guangxi Key Laboratory of Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, P. R. China.
Abstract:
In this work, 1D Cd(II) halide chain (Cd(Bz)Br) and mononuclear Cd(II) halide complex (Cd(Bz)I) were obtained by regulating halide ions. Br- ions act as µ2-Br bridges, alternately connecting with Cd(II) ions to form the trunks of the 1D chains with repeating units of -[Cd-Br2]-. The outer edges of the branches contain anti-parallel N-methylbenzimidazole (Bz) planes, which are coordinated with the Cd(II) ions. Notably, the anti-parallel Bz planes between adjacent Cd(Bz)Br chains are tightly interlocked through π-π interactions, forming a "zipper"-like connection, which promotes the intersystem crossing process and stabilizes the excited triplet. These results in room-temperature ultralong afterglow from Cd(Bz)Br with a lifetime of 34.35 ms and a delay time of up to 0.7 s. Furthermore, the butterfly-shaped mononuclear complex Cd(Bz)I exhibits a room-temperature phosphorescence (RTP) lifetime of only 5.86 ms, with an afterglow duration of less than 0.1 s. By leveraging the significant differences in the RTP of these Cd(II) halide complexes, a complex anti-counterfeiting system with multiple encryption features was constructed. This work not only provides a vivid example of manipulating halide ions to expand the range of Cd(II) halide complexes in different dimensions but also opens new horizons for regulating the RTP of Cd(II) halide complexes.
Related Concept Videos
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...
01:27¹H NMR: Long-Range Coupling
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
02:42Valence Bond Theory
01:11Nucleophilic Aromatic Substitution: Elimination–Addition
01:13¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...