Related Experiment Video
Updated: Sep 11, 2025
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
A3ZnNO3X4 (A = Rb, NH4, X = Cl, I): Regulating Cations and Halides Yields Birefringent Crystals with Significantly
Zhiyuan Zhang1,2, Yabo Wu3,4, Luyong Zhang3,4
1School of Physical Science and Technology, Xinjiang University, Urumqi 830017, Xinjiang, P.R. China.
Abstract:
Three new isostructural crystals, A3ZnNO3X4 (A = Rb, NH4; X = Cl, I) were synthesized via a mild aqueous solution method by combining π-conjugated [NO3] groups with d10 transition-metal Zn2+ ions, crystallizing in the orthorhombic space group Pnma (No. 62). All of the three compounds produce millimeter-sized crystals, with (NH4)3ZnNO3Cl4 yielding crystal as large as 17 × 14 × 4 mm3. Notably, compared with Rb3ZnNO3I4 (Δn = 0.051@546 nm), (NH4)3ZnNO3Cl4 exhibits a short UV cutoff edge (below 243 nm) and significantly enhanced birefringence (Δn = 0.085@546 nm), while (NH4)3ZnNO3I4 achieves the highest birefringence value (Δn = 0.091@546 nm) among the three crystals, demonstrating the potential as excellent UV birefringent crystals. Theoretical calculations reveal that the large birefringence of the three crystals primarily originates from the planar [NO3] triangles. Detailed analysis further attributes the differences in birefringence to variations in the cation and halide sizes.
More Related Videos
08:12Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films
Published on: September 8, 2017
07:24Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Related Concept Videos
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
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...
02:42Valence Bond Theory
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...
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...
02:46Crystal 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,...