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Numerous metalla‐supramolecular architectures have been designed using coordination‐driven self‐assembly, while the number of analogous organic architectures is still very limited. In this regard, mainly di‐, tri‐ and a few tetra‐aldehydes have been exploited as precursors in combination with appropriate di‐/tri‐amines to obtain the desired structures with limited complexities. We report here facile synthesis of two face‐directed tetrahedral organic cages (TC‐R and TC‐S) that were formed by [4+12] imine condensation of a new hexa‐aldehyde precursor with two enantiomers of 1,2‐diaminocyclohexane separately (CA‐R and CA‐S). The covalent imine cages are very large with an intrinsic porous cavity of ∼1250 Å3 and the faces of the cages consist of aromatic aldehyde units whereas each corner is occupied by three semi‐flexible diamine moieties. Palladium (PdNPs) nanoparticles (3.5±0.3 nm) were synthesized employing the cage TC‐R as a solid support via double‐solvent approach. Furthermore, the cage hosted PdNPs [Pd(0)@TC‐R‐A] exhibited efficient catalytic activity for selective homocoupling of aryl‐ and hetero‐aryl halides with high thermal stability and reusability. [ABSTRACT FROM AUTHOR]

Coordination‐driven self‐assembly of discrete molecular architectures of diverse shapes and sizes has been well studied in the last three decades. Use of dynamic imine bonds for designing analogous metal‐free architectures has become a growing challenge recently. This article reports an organic molecular barrel (OB4R) as a potential template for nucleation and stabilization of very tiny (<1.5 nm) Ag nanoparticles (AgNPs). Imine bond condensation of a rigid tetra‐aldehyde with a flexible diamine followed by imine‐bond reduction yielded the discrete tetragonal organic barrel (OB4R). The presence of a molecular pocket ornamented with eight diamine moieties gives the potential for encapsulation of silver(I). The organic barrel was finally used as a molecular vessel for the controlled nucleation of silver nanoparticles (AgNPs) with fine size tuning through binding of AgI ions in the confined space of the barrel followed by reduction. Transmission electron microscopy (TEM) analysis of the Ag0@OB4R composite revealed that the mean particle size is 1.44±0.16 nm. The composite material has approximately 52 wt % silver loading. The barrel‐supported ultrafine AgNPs [Ag0@OB4R] are found to be an efficient photocatalyst for facile Ullmann‐type aryl‐amination coupling of haloarenes at ambient temperature without using any additives. The catalyst was stable for several cycles of reuse without any agglomeration. The new composite Ag0@OB4R represents the first example of discrete organic barrel‐supported AgNPs employed as a photocatalyst in Ullmann‐type coupling reactions at room temperature. [ABSTRACT FROM AUTHOR]

Morphology of nanomaterials has a strong impact on their chemical/physical properties, and controlled synthesis of such materials with desirable morphology is a major challenge. This article presents the role of a building block in the morphology of organic cage particles. In this context, three organic cages ( A3X2, B3X2, and C3X2) were devised from triphenylamine-based dialdehydes ( A- C) and a flexible triamine ( X) by utilizing dynamic imine chemistry. All of the synthesized cages were characterized by various spectroscopic techniques, which suggested the formation of [3+2] assembled architectures. Though the cages are isostructural, structural variation in the aldehyde building blocks imparted by the incorporation of phenyl moieties into the triphenylamine core produces morphologically diverse cage particles, as indicated by SEM. The synthesized cages were found to be fluorescent; the reduced analogue of cage A3X2 ( A3X2 r) was tested to explore its use as a chemosensor for the detection of nitroaromatic explosives. The experimental findings suggest high selectivity and sensitivity of A3X2 r towards picric acid (PA) among the various nitroaromatics tested. A theoretical investigation of fluorescence quenching suggested that formation of a ground-state charge-transfer complex with a resonance energy-transfer (RET) process could be the main reason behind such selectivity of the cage towards PA. [ABSTRACT FROM AUTHOR]

Cage compounds, Enantiomeric cages, Heterogeneous catalysis, Palladium, Self-assembly Keywords: Cage compounds; Enantiomeric cages; Heterogeneous catalysis; Palladium; Self-assembly EN Cage compounds Enantiomeric cages Heterogeneous catalysis Palladium Self-assembly 1 1 1 03/11/22 20220309 NES 220309 B The Cover Feature b shows the formation of two face-directed truncated tetrahedral enantiopure organic cages by employing dynamic imine condensation reactions of a hexa-aldehyde precursor with I trans i -oriented enantiopure diamines separately. Cover Feature: Face-Directed Tetrahedral Organic Cage Anchored Palladium Nanoparticles for Selective Homocoupling Reactions (Eur. J. Inorg. [Extracted from the article]