Control of Metal Arrays Based on Heterometallics Masquerading in Heterochiral Aggregations of Chiral Clothespin‐Shaped Complexes

Abstract

Heterometal arrays in molecular aggregations were obtained by the spontaneous and ultrasound-induced gelation of organic liquids containing the chiral, clothespin-shaped trans-bis(salicylaldiminato) d8 transition-metal complexes 1. Heterometallic mixtures of complexes 1 a (Pd) and 1 b (Pt) underwent strict heterochiral aggregation entirely due to the organic shell structure of the clothespin shape, with no effect of the metal cores. This phenomenon provides an unprecedented means of generating highly controlled heterometallic arrangements such as alternating sequences [(+)-Pd(-)-Pt(+)-Pd(-)-Pt⋅⋅⋅] as well as a variety of single metal-enriched arrays (e.g., [(+)-Pt(-)-Pd(+)-Pd(-)-Pd(+)-Pd(-)-Pd⋅⋅⋅] and [(+)-Pd(-)-Pt(+)-Pt(-)-Pt(+)-Pt(-)-Pt⋅⋅⋅]) upon the introduction of an optically active masquerading unit with a different metal core in the heterochiral single-metal sequence. The present method can be applied to form various new aggregates with optically active Pd and Pt units, to allow 1) tuning of the gelation ultrasound sensitivity based on the different hearing abilities of the metal units; 2) aggregation-induced chirality transfer between heterometallic species; and 3) aggregation-induced chirality enhancement. A mechanistic rationale is proposed for these molecular aggregations based on the molecular structures of the units and the morphologies of the aggregates.

Single‐Point Remote Control of Flapping Motion in Clothespin‐Shaped Bimetallic Palladium Complexes Based on the N(sp2)–N(sp3) Interconversion in Amide Functionalities

“…As part of ap rogram aimed at the development of new functional materials based on the controlled d-p conjugation of flexible trans-bis(salicylaldiminato) d 8 transition-metal platforms, [11,12] we have been investigating the molecular mobility of the clothespin-shaped complexes anti-2-4 (Scheme 1) in whicht wo co-facially coordinated blades exhibit specific open/ close flappingm otion in the solution state as ar esult of an intramolecular p-stacking interaction with the support of flexible pentamethylene linkers. [13] The flapping motion of the clothespin-shaped moleculesi sanew typeo fa nisotropic molecular movement that is specifically generated by the synergistic contributionso ft he weak d-p conjugation of the palladium coordinated blades and the integration of the multipoint bonding rotationo ft he linkers,w hich can be accomplished by the balance between the flexibility and regulation of the blades and linkers.…”

Emission Control by Molecular Manipulation of Double‐Paddled Binuclear PtII Complexes at the Air‐Water Interface

“…These observations indicate that almost non‐emissive 1 b , e , f undergo drastic increases in their emission intensities just prior to the formation of their monolayers, with subsequent continuous increase in emission intensity during the compression process until the respective points of monolayer collapse. The continuous increases in emission intensities of 1 b , e monolayers during mechanical compression from 0.8 nm 2 can be ascribed to the fixing of the phosphorescent units by infinite interpenetrative stacking, which will be discussed later.…”

Using Complementary Ligand Denticity to Direct Metallosupramolecular Structure about Metal Ions with Square‐Planar Geometry

“…Even more intriguingly, the racemic (±) anti ‐[Pd 2 L7 2 ] complex demonstrated solution‐phase heterochiral dimerization, with 31‐fold selectivity over homochiral aggregation. They have subsequently used this property using optically pure (+) anti ‐[Pd 2 L5 2 ] and (−) anti ‐[Pt 2 L5 2 ] to form pseudo‐racemates with the same propensity for heterochiral association, giving control over heterometallic arrangements in the gel phase …”