Related Experiment Video
Updated: Jan 10, 2026
16:24
Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
19.2K
Steric Control over Heteroleptic Trigonal Prisms: From Integrative Self-Sorting to Programmable Spin-State Modulation
Yu-Xiao Chen1, Hua-Liang Yue1, Yu-Qing Wu1
1Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Liangxiang Campus, Beijing Institute of Technology, Beijing 102488, Peoples' Republic of China.
Journal of the American Chemical Society
|November 24, 2025
Summary
Researchers developed a new method using steric constraints to create complex metal-organic cages (MOCs) with precise structures. This breakthrough enables chemically controlled transformations and stimulus-responsive magnetism in MOCs.
Area of Science:
- Supramolecular Chemistry
- Coordination Chemistry
- Materials Science
Background:
- Constructing well-defined heteroleptic metal-organic cages (MOCs) via integrative self-sorting remains a significant challenge.
- Existing methods often struggle to control the precise assembly of multiple ligand types into specific cage architectures.
Purpose of the Study:
- To develop a general strategy for the quantitative formation of heteroleptic trigonal-prismatic MOCs.
- To demonstrate chemically triggered cage-to-cage transformations and stimulus-responsive magnetic properties.
Main Methods:
- Utilized backbone steric constraints and edge-length complementarity for selective ligand assembly.
- Employed C3-symmetric tris-aniline ligands to direct horizontal orientation of complementary ligands.
- Investigated Zn2+-based cages for chemical addressability and Ca2+-mediated interconversion.
- Studied Fe2+-based cages to explore spin crossover (SCO) phenomena via ligand exchange.
Main Results:
- Achieved quantitative formation of heteroleptic trigonal-prismatic cages [M6LA2L'3]12+ using steric control.
- Demonstrated reversible fluoride binding and cage-to-cage interconversion in Zn2+-based cages.
- Observed an unusual ambient-temperature spin crossover (SCO) in a heteroleptic Fe2+-based trigonal prism (2b-Fe).
- Showcased ligand modification's tunability of spin states, with an imidazole-based analogue (2a-Fe) exhibiting permanent high-spin character.
Conclusions:
- Backbone steric bulk is a viable general approach for achieving integrative self-sorting in MOC synthesis.
- Chemically gated cage-to-cage transformations and stimulus-responsive magnetism can be encoded into discrete multinuclear cages.
- The study introduces a new structural archetype for SCO-active heteroleptic trigonal prisms, expanding the scope of magnetic MOC materials.
Related Concept Videos
02:33Stereoisomerism of Cyclic Compounds
10.9K
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
10.9K
02:52Stereoisomerism
13.8K
Isomerism in Complexes
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...
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...
13.8K
02:05Prochirality
4.8K
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
4.8K
![[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12422.jpg&w=3840&q=75)
01:21[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
3.3K
The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.
3.3K
02:25Molecules with Multiple Chiral Centers
14.8K
Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...
14.8K
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
3.8K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
3.8K