Flexible Vertex Engineers the Controlled Assembly of Distorted Supramolecular Tetrahedral and Octahedral Cages

Abstract

Designing and building unique cage assemblies attract increasing interest from supramolecular chemists but remain synthetically challenging. Herein, we propose the use of a flexible vertex with adjustable angles to selectively form highly distorted tetrahedral and octahedral cages, for the first time, in which the flexible vertex forms from the synergistic effect of coordination and covalent interactions. The inherent interligand angle of the vertex can be modulated by guest anions present, which allows for the fine-tuning of different cage geometries. Furthermore, the reversible structural transformation between tetrahedral and octahedral cages was achieved by anion exchange monitored by mass spectrometric technique, the smaller anions favoring tetrahedral cages, while the larger anions supporting octahedral cages. Additionally, the KBr-based cage thin films exhibited prominent enhancement of their third-order NLO responses in two or three orders of magnitude compared to those obtained for their corresponding solutions. This work not only provides a new methodology to build irregular polyhedral structures in a controlled and tunable way but also provides access to new kinds of promising functional optical materials.

Third-Order Nonlinear Optical Modulation Behavior of Photoresponsive Bimetallic MOFs

“…Doping MOFs into a polymer substrate to form hybrid films is considered as an effective strategy for realizing the practical application of solid samples in the NLO field. − In this study, poly­(methyl methacrylate) (PMMA) was chosen as the substrate due to its excellent film-forming properties, high mechanical flexibility, and optical transparency . The MOFs were incorporated into the PMMA matrix to prepare PMMA hybrid films with a doping content of 0.5 wt %.…”

Solvent-controlled synthesis of an Al12-oxo molecular ring and Al24-oxo truncated metallo-cube

“…8 For coordination nanocages, based on the construction rules of polyhedra, suitable organic ligands with specific configurations are often selected for their syntheses. [9][10][11][12][13][14] However, the nanoclusters assembled from simple ingredients are elusory and the acquisition of geometric structures lacks the presupposition. As a famous polyhedral cluster, C 60 is constructed by 12 pentagons and 20 hexagons, which is a classical Archimedean polyhedron, truncated icosahedron, inspiring various creative ideas for building fullerene-like nanopolyhedral metal clusters.…”

Exploration and Insights on Topology Adjustment of Giant Heterometallic Cages Featuring Inorganic Skeletons Assisted by Machine Learning

“…Inspired by the functionality of enzyme pockets in selective catalysis, specific recognition, etc., the chemical synthesis of cage-like compounds has received huge research interests in past decades. − Thanks to the development of the organic synthesis methodology and coordination chemistry, relatively mature design and synthesis methods have been developed for molecular cages with organic , or metal–organic skeletons. − The cage-like assemblies constructed by inorganic skeletons have rigid skeletons and endow the functionality from synergic multimetal centers. − However, despite the possibility of a rational structure design, the poor synthetic controllability and an enormous possible structure space of the coordination components make the precise design and synthesis of them still challenging. As a result, cage-like compounds featuring inorganic skeletons normally come from serendipitous findings via trial-and-error.…”