Guest Segregation in Heteromeric Multicage Systems.

Dynamically interconvertible metallo-supramolecular multicomponent assemblies, coexisting orthogonally in solution, serve as simplified mimics for complex networks found in biological systems. Building on recent advances in controlling the nonstatistical self-assembly of heteroleptic coordination cages and heteromeric completive self-sorting, i.e.

Control of Interlocking Mode in PdL Cage Catenanes.

Precise control over the catenation process in interlocked supramolecular systems remains a significant challenge. Here, we report a system in which a lantern-shaped PdL cage can dimerize to form two distinct PdL catenanes with different interlocking degree: a previously described quadruply interlocked double cage motif of D symmetry and an unprecedented triply interlocked structure of C symmetry. While the former structure features a linear arrangement of four Pd(II) centers, separated by three mechanically linked pockets, the new motif has a staggered shape.

Solvent-Directed Social Chiral Self-Sorting in PdL Coordination Cages.

A family of Pd cages prepared from ligands based on an axially chiral diamino-[1,1'-biazulene] motif (serving as a unique azulene-based surrogate of the ubiquitous BINOL moiety) is reported. We show that preparing a cage starting from the racemate of a shorter bis-monodentate ligand derivative, equipped with pyridine donor groups, leads to integrative ("social") chiral self-sorting, exclusively yielding the product, but only in a selection of solvents. This phenomenon is driven by individual solvent molecules acting as hydrogen bonding tethers between the amino groups of neighboring ligands, thereby locking the final coordination cage in a single isomeric form.

Interplay of Stereochemistry and Charge Governs Guest Binding in Flexible ZnL Cages.

Here, we report the synthesis of a family of chiral ZnL tetrahedral cages by subcomponent self-assembly. These cages contain a flexible trialdehyde subcomponent that allows them to adopt stereochemically distinct configurations. The incorporation of enantiopure 1-phenylethylamine produced Δ and Λ enantiopure cages, in contrast to the racemates that resulted from the incorporation of achiral 4-methoxyaniline.

London dispersion driven compaction of coordination cages in the gas-phase - a combined ion mobility and theoretical study.

Large self-assembled systems (such as metallosupramolecular rings and cages) can be difficult to structurally characterize, in particular when they show a highly dynamic behavior. In the gas-phase, Ion Mobility Spectrometry (IMS), in tandem with Electrospray Ionization Mass Spectrometry (ESI MS), can yield valuable insights into the size, shape and dynamics of such supramolecular assemblies. However, the detailed relationship between experimental IMS data and the actual gas-phase structure is still poorly understood for soft and flexible self-assemblies.

Assessing the combination efficiency of some unconventional feed resources with concentrates and Chloris gayana grass in mitigating ruminal methane production in vitro.

In a preliminary in vitro study, leaves of Acacia nilotica, Prosopis juliflora, Cajanus cajan, Leucaena leucocephala and seed kernel of Mangifera indica were identified as potential candidates in mitigating ruminal methane (CH) production. The objective of the current study was to investigate the combination efficiency of these unconventional feeds with concentrate mix (CM) or Chloris gayana grass in CH reduction. Two feed combinations in different proportions were incubated in vitro with buffered rumen fluid at Hohenheim Gas test.

Ligand Conformation Controls Assembly of a Helicate/Mesocate, Heteroleptic [PdLL'] Cages and a Six-Jagged [PdL] Ring.

Molecular building blocks, capable of adopting several strongly deviating conformations, are of particular interest in the development of stimuli-responsive self-assemblies. The pronounced structural flexibility of a short acridone-based bridging ligand, equipped with two monodentate isoquinoline donors, is herein exploited to assemble a surprisingly diverse series of coordination-driven Pd(II) architectures. First, it can form a highly twisted PdL helicate, transformable into the corresponding mesocate, controlled by temperature, counter anion and choice of solvent.

Shape-Complementary Multicomponent Assembly of Low-Symmetry Co(III)Salphen-Based Coordination Cages.

While metal-mediated self-assembly is a popular technique to construct discrete nanosized objects, highly symmetric structures, built from one type of ligand at a time, are dominating reported systems. The tailored integration of a set of different ligands requires sophisticated approaches to avoid narcissistic separation or formation of statistical mixtures. Here, we demonstrate how the combination of three structure-guiding effects (metal-templated macrocyclization, additional bridging ligands and shape-complementarity) based on Co(III)salphen metal nodes allows for a rational and high-yielding synthesis of structurally complex, lantern-shaped cages with up to four differentiable bridges.

Non-Templated Assembly of D-Symmetric PdL Rings by Precise Ligand Angle Adjustment.

We report a series of Pd(II)L coordination rings for which nuclearity is controlled by the binding angle of the corresponding bis-monodentate bridging ligands. Judicious choice of the angle within a family of rather rigid ligands allowed for the first-time to synthesize a homoleptic five-membered PdL ring that does not require any template to form. We demonstrate that control over the ring size is maintained both in the solid-, solution-, and gas-phase.

Heteromeric Completive Self-Sorting in Coordination Cage Systems.

Heteroleptic coordination cages, nonstatistically assembled from a set of matching ligands, can be obtained by mixing individual components or via cage-to-cage transformations from homoleptic precursors. Based on the latter approach, we here describe a new level of self-sorting in coordination cage systems, namely, 'heteromeric completive self-sorting'. Here, two heteroleptic assemblies of type PdAB and PdAC, sharing one common ligand component A but differing in the other, are shown to coexist in solution.

Coherent Terahertz Detection via Ultrafast Dynamics of Hot Dirac Fermions in Graphene.

Graphene has recently been shown to exhibit ultrafast conductivity modulation due to periodic carrier heating by either terahertz (THz) waves, leading to self-induced harmonic generation, or the intensity beat note of two-color optical radiation. We exploit the latter to realize an optoelectronic photomixer for coherent, continuous-wave THz detection, based on a photoconductive antenna with multilayer CVD-grown graphene in the gap. While for biased THz emitters the dark current would pose a serious detriment for performance, we show that this is not the case for bias-free THz detection and demonstrate detection up to frequencies of at least 700 GHz at room temperature, even without optimized tuning of the doping.

Guest-Induced Reversible Transformation between an Azulene-Based PdL Lantern-Shaped Cage and a PdL Tetrahedron.

Azulene, a blue structural isomer of naphthalene, is introduced as the backbone for a new family of Pd(II)-based self-assemblies. Three organic ligands, equipped with varying donor groups, produce three [PdL] cages of different cavity dimensions. Unexpectedly, the addition of organic disulfonate guests to the smallest lantern-shaped cage (featuring pyridine donors) led to a rapid and quantitative transformation to a distorted-tetrahedral [PdL] species.

Chemoenzymatic Photoreforming: A Sustainable Approach for Solar Fuel Generation from Plastic Feedstocks.

Plastic upcycling through catalytic transformations is an attractive concept to valorize waste, but the clean and energy-efficient production of high-value products from plastics remains challenging. Here, we introduce chemoenzymatic photoreforming as a process coupling enzymatic pretreatment and solar-driven reforming of polyester plastics under mild temperatures and pH to produce clean H and value-added chemicals. Chemoenzymatic photoreforming demonstrates versatility in upcycling polyester films and nanoplastics to produce H at high yields reaching ∼10-10 μmol g and activities at >500 μmol g h.

Engineering Soluble Diketopyrrolopyrrole Chromophore Stacks from a Series of Pd(II)-Based Ravels.

A strategy to engineer the stacking of diketopyrrolopyrrole (DPP) dyes based on non-statistical metallosupramolecular self-assembly is introduced. For this, the DPP backbone is equipped with nitrogen-based donors that allow for different discrete assemblies to be formed upon the addition of Pd(II), distinguished by the number of π-stacked chromophores. A Pd L three-ring, a heteroleptic Pd L L' ravel composed of two crossing DPPs (flanked by two carbazoles), and two unprecedented self-penetrated motifs (a Pd L triple and a Pd L quadruple stack), were obtained and systematically investigated.

Eradication of complex in cystic fibrosis patients with inhalation of amiloride and tobramycin combined with oral cotrimoxazole.

https://bit.ly/40oOMIn.

Room-Temperature-Stable Diazoalkenes by Diazo Transfer from Azides: Pyridine-Derived Diazoalkenes.

Recently, stable diazoalkenes have received significant attention as a new substance class in organic chemistry. While their previous synthetic access was exclusively limited to the activation of nitrous oxide, we here establish a much more general synthetic approach utilizing a Regitz-type diazo transfer with azides. Importantly, this approach is also applicable to weakly polarized olefins such as 2-pyridine olefins.

Maximized axial helicity in a PdL cage: inverse guest size-dependent compression and mesocate isomerism.

Helicity is an archetypal structural motif of many biological systems and provides a basis for molecular recognition in DNA. Whilst artificial supramolecular hosts are often helical, the relationship between helicity and guest encapsulation is not well understood. We report a detailed study on a significantly coiled-up PdL metallohelicate with an unusually wide azimuthal angle (∼176°).

Photoinduced host-to-guest electron transfer in a self-assembled coordination cage.

A [PdL] coordination cage, assembled from electron-rich phenothiazine-based ligands and encapsulating an electron-deficient anthraquinone-based disulfonate guest, is reported. Upon excitation at 400 nm, transient absorption spectroscopy unveils photoinduced electron transfer from the host's chromophores to the guest, as indicated by characteristic spectral features assigned to the oxidized donor and reduced acceptor. The structure of the host-guest complex was characterized by NMR spectroscopy, mass spectrometry and single-crystal X-ray analysis.

A Charge-Neutral Self-Assembled LZn Helicate as Bench-Stable Receptor for Anion Recognition at Nanomolar Concentration.

The field of anion recognition chemistry is dominated by two fundamental approaches to design receptors. One relies on the formation of covalent bonds resulting in organic and often neutral host species, while the other one utilizes metal-driven self-assembly for the formation of charged receptors with well-defined nanocavities. Yet, the combination of their individual advantages in the form of charge-neutral metal-assembled bench-stable anion receptors is severely lacking.

Endohedrally Functionalized Heteroleptic Coordination Cages for Phosphate Ester Binding.

Metallosupramolecular hosts of nanoscopic dimensions, which are able to serve as selective receptors and catalysts, are usually composed of only one type of organic ligand, restricting diversity in terms of cavity shape and functional group decoration. We report a series of heteroleptic [Pd A B ] coordination cages that self-assemble from a library of shape complementary bis-monodentate ligands in a non-statistical fashion. Ligands A feature an inward pointing NH function, able to engage in hydrogen bonding and amenable to being functionalized with amide and alkyl substituents.

Minimal-invasive anterior approach to the hip provides a better surgery-related and early postoperative functional outcome than conventional lateral approach after hip hemiarthroplasty following femoral neck fractures.

Introduction: Femoral neck fractures (FNF) are one of the most frequent fractures among elderly patients and commonly require surgical treatment. Bipolar hip hemiarthroplasty (BHHA) is mostly performed in these cases.

Material And Methods: In the present retrospective study geriatric patients with FNF (n = 100) treated either by anterior minimal-invasive surgery (AMIS; n = 50) or lateral conventional surgery (LCS; n = 50) were characterized (age at the time of surgery, sex, health status/ASA score, walking distance and need for walking aids before the injury) and intraoperative parameters (duration of surgery, blood loss, complications), as well as postoperative functional performance early (duration of in-patient stay, radiological leg length discrepancy, ability to full weight-bearing, mobilization with walking aids) and 12 months (radiological signs of sintering, clinical parameters, complication rate) after surgery were analyzed.

Cooperativity of steric bulk and H-bonding in coordination sphere engineering: heteroleptic Pd cages and bowls by design.

Recently developed self-assembly strategies allow to rationally reduce the symmetry of metallosupramolecular architectures. In addition, the combination of multiple ligand types without creating compound mixtures has become possible. Among several approaches to realize non-statistical heteroleptic assembly, Coordination Sphere Engineering (CSE) makes use of secondary repulsive or attractive interactions in direct vicinity of the metal nodes.