Related Experiment Video
Updated: Aug 12, 2025

Seedless Growth of Bismuth Nanowire Array via Vacuum Thermal Evaporation
Published on: December 21, 2015
Effect of the Host Lattice Environment on the Expression of 5s2 Lone-Pair Electrons in a 0D Bismuth-Based Metal
Yihao Chen1, Lei Zhou1, Shuigen Zhou1
1Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education School of Chemistry and Chemical Engineering, Southwest University, Chongqing400715, P. R. China.
Abstract:
ns2-Metal halide perovskites have attracted wide attention due to their fascinating photophysical properties. However, achieving high photoluminescence (PL) properties is still an enormous challenge, and the relationship between the lattice environment and ns2-electron expression is still elusive. Herein, an organic-inorganic Bi3+-based halide (C5H14N2)2BiCl6·Cl·2H2O (C5H14N22+ = doubly protonated 1-methylpiperazine) with a six-coordinated structure has been successfully prepared, which, however, exhibits inferior PL properties due to the chemically inert expression of Bi3+-6s2 lone-pair electrons. After reasonably embedding Sb3+ with 5s2 electrons into the lattice of (C5H14N2)2BiCl6·Cl·2H2O, the host lattice environment induces the Sb-Cl moiety to change from the original five-coordinated to six-coordinated structure, thereby resulting in a broad-band yellow emission with a PL efficiency up to 50.75%. By utilizing the host lattice of (C5H14N2)2BiCl6·Cl·2H2O, the expression of Sb3+-5s2 lone-pair electrons is improved and thus promotes the radiative recombination from the Sb3+-3P1 state, resulting in the enhanced PL efficiency. This work will provide an in-depth insight into the effect of the local structure on the expression of Sb3+-5s2 lone-pair electrons.
Related Concept Videos
Valence Bond Theory
VSEPR Theory and the Effect of Lone Pairs
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...
Trends in Lattice Energy: Ion Size and Charge
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
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...

