Related Experiment Video
Updated: Sep 18, 2025
Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Spontaneous Symmetry Breaking in Liquid Crystalline Phase of platinum(II)-Based Bent-Shaped Achiral Metallomesogens
Jinxin Jiang1, Xueqing Ning1, Rui Zeng1
1College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, P. R. China.
Abstract:
Achiral molecules can generate supramolecular chirality through spontaneous symmetry breaking during molecular assembly, offering new insights into the origin of molecular homochirality and the design of advanced chiral materials. Herein we report the design and synthesis of bent-core achiral platinum(II) complexes using phenylpyridine (ppy) derivatives as the cyclometalated ligand and acetylacetone (acac) as the auxiliary ligand. The liquid crystal properties and self-assembly behavior could be modulated by altering the type and number of substituents on the biphenyl unit. Spontaneous symmetry breaking in the liquid crystal phase can be detected first in a quenched liquid crystal film. These complexes demonstrate efficient circularly polarized phosphorescence, with the luminescence asymmetry factor (glum) reaching the order of 10-3. This work offers further insights into the development of novel systems for spontaneous symmetry breaking and demonstrates a distinctive approach to creating optically active materials derived from achiral platinum(II)-based metallomesogens.
Related Concept Videos
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,...
02:37Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
02:25Chirality
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
02:11Conformations of Cyclohexane
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...
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...