Self-organization of amino-acid-derived NDI assemblies into a nanofibrillar superstructure with humidity sensitive n-type semiconducting properties

The hierarchical self-assembly of L-tyrosine substituted naphthalenediimide has been explored in solution by NMR spectroscopy and in the solid-state by atomic force microscopy. Spontaneous non-covalent polymerisation led to the formation of a three-dimensional fibre-like supramolecular polymer with n-type semiconducting properties

Photoisomerisation and light-induced morphological switching of a polyoxometalate–azobenzene hybrid

The functionalization of a spherical Keplerate-type polyoxometalate {Mo72V30} with a cationic azobenzene surfactant has been achieved through ionic self-assembly. The photoisomerisation reaction of this complex, which emerges in a light-triggered aggregation–disaggregation process, has been followed by 1H NMR spectroscopy, dynamic light scattering, absorption spectroscopy and scanning electron microscopy analyses

Intrinsic Effect of Pyridine-N-Position on Structural Properties of Cu-Based Low-Dimensional Coordination Frameworks

Metal-organic assemblies have received significant attention for catalytic and other applications, including gas and energy storage, due to their porosity and thermal/chemical stability. Here, we report the synthesis and physicochemical characterization of three metallosupramolecular assemblies consisting of isomeric ambidentate pyridyl-β-diketonate ligands L1–L3 and Cu(II) metal ions. It has been demonstrated that the topology and dimensionality of generated supramolecular aggregates depend on the location of the pyridine nitrogen donor atom in L1–L3. This is seen in characterization of two distinct 2D polymeric assemblies, i.e., [Cu(L1)2]n and [Cu(L2)2]n, in which both β-diketonate and pyridine groups are coordinated to the Cu(II) center, as well as in characterization of the mononuclear 1D complex Cu(L3)2, in which the central atom is bound only by two β-diketonate units

pH-Induced Linkage Isomerism of Pd(II) Complexes: A Pathway to Air- and Water-Stable Suzuki–Miyaura-Reaction Catalysts

The Pd­(II) complexes of the ambidentate pyridyldiketones 2,2-dimethyl-5-(3- or 4-pyridyl)­pentane-3,5-dione are readily prepared in their linkage isomeric forms by the appropriate pH control during syntheses. The isolated diketonate- or pyridine-bound species can be interconverted with essentially 100% efficiency by treatment with an acid or base, respectively. Under the normal basic conditions for a Suzuki–Miyaura coupling, only the diketonate forms are present and act as very efficient catalysts for this reaction. The dynamic nature of the presented complexes allows the catalytic process to be quenched and reactivated at any stage without the risk of losing the catalyst’s activity

Steering the Self-Assembly Outcome of a Single NDI Monomer into Three Morphologically Distinct Supramolecular Assemblies, with Concomitant Change in Supramolecular Polymerization Mechanism

Noncovalent self-assembly creates an effective route to highly sophisticated supramolecular polymers with tunable properties. However, the outcome of this assembly process is highly dependent on external conditions. In this work, a monomeric naphthalene diimide (NDI), designed to allow solubility in a wide range of solvents, can assemble into three distinct noncovalent supramolecular species depending on solvent composition and temperature. Namely, while the self-assembly in chlorinated solvents yields relatively short, hydrogen-bonded nanotubes, the reduction of solvent polarity changes the assembly outcome, yielding π–π stacking polymers, which can further bundle into a more complex aggregate. The obtained polymers differ not only in their global morphology but—more strikingly—also in the thermodynamics and kinetics of their supramolecular self-assembly, involving isodesmic or two-stage cooperative assembly with kinetic hysteresis, respectively. Ultimately, three distinct assembly states can be accessed in a single experiment.</p

Dynamic covalent synthesis

Dynamic covalent synthesis aims to precisely control the assembly of simple building blocks linked by reversible covalent bonds to generate a single, structurally complex, product. In recent years, considerable progress in the programmability of dynamic covalent systems has enabled easy access to a broad range of assemblies, including macrocycles, shape-persistent cages, unconventional foldamers and mechanically-interlocked species (catenanes, knots, etc.). The reversibility of the covalent linkages can be either switched off to yield stable, isolable products or activated by specific physico-chemical stimuli, allowing the assemblies to adapt and respond to environmental changes in a controlled manner. This activatable dynamic property makes dynamic covalent assemblies particularly attractive for the design of complex matter, smart chemical systems, out-of-equilibrium systems, and molecular devices.peerReviewe

Multi‐Stimuli‐Responsive Network of Multicatalytic Reactions using a Single Palladium/Platinum Catalyst

Publication status: PublishedFunder: Morrell Fund, Yusuf Hamied Department of Chemistry, University of CambridgeGiven her unrivalled proficiency in the synthesis of all molecules of life, nature has been an endless source of inspiration for developing new strategies in organic chemistry and catalysis. However, one feature that remains thus far beyond chemists’ grasp is her unique ability to adapt the productivity of metabolic processes in response to triggers that indicate the temporary need for specific metabolites. To demonstrate the remarkable potential of such stimuli‐responsive systems, we present a metabolism‐inspired network of multicatalytic processes capable of selectively synthesising a range of products from simple starting materials. Specifically, the network is built of four classes of distinct catalytic reactions—cross‐couplings, substitutions, additions, and reductions, involving three organic starting materials—terminal alkyne, aryl iodide, and hydrosilane. All starting materials are either introduced sequentially or added to the system at the same time, with no continuous influx of reagents or efflux of products. All processes in the system are catalysed by a multifunctional heteronuclear PdII/PtII complex, whose performance can be controlled by specific additives and external stimuli. The reaction network exhibits a substantial degree of orthogonality between different pathways, enabling the controllable synthesis of ten distinct products with high efficiency and selectivity through simultaneous triggering and suppression mechanisms

Multi‐Stimuli‐Responsive Network of Multicatalytic Reactions using a Single Palladium/Platinum Catalyst

Publication status: PublishedFunder: Morrell Fund, Yusuf Hamied Department of Chemistry, University of CambridgeGiven her unrivalled proficiency in the synthesis of all molecules of life, nature has been an endless source of inspiration for developing new strategies in organic chemistry and catalysis. However, one feature that remains thus far beyond chemists’ grasp is her unique ability to adapt the productivity of metabolic processes in response to triggers that indicate the temporary need for specific metabolites. To demonstrate the remarkable potential of such stimuli‐responsive systems, we present a metabolism‐inspired network of multicatalytic processes capable of selectively synthesising a range of products from simple starting materials. Specifically, the network is built of four classes of distinct catalytic reactions—cross‐couplings, substitutions, additions, and reductions, involving three organic starting materials—terminal alkyne, aryl iodide, and hydrosilane. All starting materials are either introduced sequentially or added to the system at the same time, with no continuous influx of reagents or efflux of products. All processes in the system are catalysed by a multifunctional heteronuclear PdII/PtII complex, whose performance can be controlled by specific additives and external stimuli. The reaction network exhibits a substantial degree of orthogonality between different pathways, enabling the controllable synthesis of ten distinct products with high efficiency and selectivity through simultaneous triggering and suppression mechanisms

Multi-Stimuli-Responsive Network of Multicatalytic Reactions using a Single Palladium/Platinum Catalyst.

Given her unrivalled proficiency in the synthesis of all molecules of life, nature has been an endless source of inspiration for developing new strategies in organic chemistry and catalysis. However, one feature that remains beyond chemists' grasp is her unique ability to adapt the productivity of metabolic processes in response to triggers that indicate the temporary need for specific metabolites. To demonstrate the remarkable potential of such stimuli-responsive systems, we present a metabolism-inspired network of multicatalytic processes capable of selectively synthesising a range of products from simple starting materials. Specifically, the network is built of four classes of distinct catalytic reactions - cross-couplings, substitutions, additions, and reductions, involving three organic starting materials - terminal alkyne, aryl iodide, and hydrosilane. All starting materials are either introduced sequentially or added to the system at the same time, with no continuous influx of reagents or efflux of products. All processes in the system are catalysed by a multifunctional heteronuclear PdII/PtII complex, whose performance can be controlled by specific additives and external stimuli. The reaction network exhibits a substantial degree of orthogonality between different pathways, enabling the controllable synthesis of ten distinct products with high efficiency and selectivity through simultaneous triggering and suppression mechanisms