Related Experiment Video
Updated: Aug 21, 2026

Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Multidentate Anion [C6H6NO6]3- Coordinated Hybrid Bismuth Complex Single Crystal for Stable X-Ray Detection With High
Youkui Xu1, ZhenHua Li1, Yutian Lei1
1School of Physical Science and Technology, Lanzhou Center for Theoretical Physics, Key Laboratory of Theoretical Physics of Gansu Province, Key Laboratory of Quantum Theory and Applications of MoE, and Gansu Provincial Research Center For Basic Disciplines of Quantum Physics, Lanzhou University, Lanzhou, Gansu, China.
None:
Replacing halides with pseudohalides is effective strategy to address the ion migration and corrosion issues in bismuth (Bi) halides. However, pseudohalides also suffer from weak single-point bonding, and larger molecular size enhances electron localization that are unfavorable for carrier transport. Therefore, it is crucial to develop new ligand that both ensures structural stability and delivers excellent detection performance. Herein, we first designed a novel multidentate ligand, Nitrilotriacetate [N(CH2COO)3]3- (NTA), which forms (NH4)3Bi(NTA)2 through coordination with Bi. Theoretical calculations reveal that NTA coordination enhances the Bi─O bond, raising migration energies of Bi and O to 5.57 and 1.04 eV, which are significantly higher than those of Bi and I in (NH4)3Bi2I9 (1.94 and 0.42 eV). Furthermore, unlike in halide complex where the band edges are dominated by Bi and I atomic orbitals, the band edges of (NH4)3Bi(NTA)2 are primarily contributed by NTA molecular orbitals, and the hydrogen bond network (N─H···O) effectively links the individual NTA3-, enhancing the carrier transport efficiency. Ultimately, (NH4)3Bi(NTA)2-based device demonstrated ultralow limit of detection 24.83 nGy/s and high sensitivity (6116 µC Gy-1 cm-2), along with no obvious corrosion for electrodes. This work provides new approach to address the challenges of halide coordination complexes.
Related Concept Videos
Colors 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.
Determination of Crystal Structures
Crystal 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...
Coordination Number and Geometry
X-ray Diffraction of Biological Samples
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...

