Highly Selective Construction of Unique Cyclic [4]catenanes ( 841 ) Induced by Multiple Noncovalent Interactions.

The synthesis of high-ordered mechanically interlocked supramolecular structures is an extremely challenging topic. Only two linear [4]catenanes have been reported so far and there is no defined strategy to obtain cyclic [4]catenane. Herein, two unprecedented cyclic [4]catenanes, 1 and 2, were prepared in high yields.

Hydrogen Atom Abstraction and Reduction Study of 21-Thiaporphyrin and 21,23-Dithiaporphyrin.

The metal-free porphyrins protonation has gained interest over five decades because its structure modification and hardly monoacid intermediate isolation. Here, upon the hydrogen atom abstraction processes, one step diproptonated HSTTP(BF) (STTP = 5,10,15,20-tetraphenyl-21-thiaporphyrin) () and stepwise protonated HSTTPSbCl () and diprotonated HSTTP(BF) () (STTP = 5,10,15,20-tetraphenyl-21,23-thiaporphyrin) compounds were obtained using HSTTP and STTP with oxidants. The closed-shell protonated compounds were fully characterized using XRD, UV-vis, IR and NMR spectra.

Triply Interlocked [2]catenanes: Rational Synthesis, Reversible Conversion Studies and Unprecedented Application in Photothermal Responsive Elastomer.

Triply interlocked [2]catenane complexes featuring two identical, mechanically interlocked units are extraordinarily rare chemical compounds, whose properties and applications remain open to detailed studies. Herein, we introduce the rational design of a new ligand precursor, L1, suitable for the synthesis of six triply interlocked [2]catenanes by coordination-driven self-assembly. The interlocked compounds can be reversibly converted into the corresponding simple triangular prism metallacage by addition of HO or DMF solvents to their CHOH solutions, thereby demonstrating the importance of π⋅⋅⋅π stacking and hydrogen bonding interactions in the formation of triply interlocked [2]catenanes.

Encapsulation engineering of porous crystalline frameworks for delayed luminescence and circularly polarized luminescence.

Delayed luminescence (DF), including phosphorescence and thermally activated delayed fluorescence (TADF), and circularly polarized luminescence (CPL) exhibit common and broad application prospects in optoelectronic displays, biological imaging, and encryption. Thus, the combination of delayed luminescence and circularly polarized luminescence is attracting increasing attention. The encapsulation of guest emitters in various host matrices to form host-guest systems has been demonstrated to be an appealing strategy to further enhance and/or modulate their delayed luminescence and circularly polarized luminescence.

A Coordination-Driven Self-Assembly and NIR Photothermal Conversion Study of Organometallic Handcuffs.

Due to their fascinating topological structures and application prospects, coordination supramolecular complexes have continuously been studied by scientists. However, the controlled construction and property study of organometallic handcuffs remains a significant and challenging research subject in the area of supramolecular chemistry. Hence, a series of tetranuclear organometallic and heterometallic handcuffs bearing different size and metal types were rationally designed and successfully synthesized by utilizing a quadridentate pyridyl ligand (tetra-(3-pyridylphenyl)ethylene) based on three Cp*Rh (Cp* = -CMe) fragments bearing specific longitudinal dimensions and conjugated planes.

Self-Assembly and Photothermal Conversion of MetallaRussian Doll and Metalla[2]catenanes Induced via Multiple Stacking Interactions.

A variety of organometallic supramolecular architectures have been constructed over the past decades and their properties were also explored via different strategies. However, the synthesis of metalla-Russian doll is still a fascinating challenge. Herein, a series of new coordination supramolecular complexes, including a metalla-Russian doll, metalla[2]catenanes, and metallarectangles, were synthesized by using meticulously selected Cp*Rh (Cp* = η-CMe) building units (E1, E2, and E3) and three rigid anthracylpyridine ligands (L1, L2, and L3) via a self-assembly strategy.

Selective Synthesis and Structural Transformation of a 4-Ravel Containing Four Crossings and Featuring Cp*Rh/Ir Fragments.

Intricately interwoven topologies are continually being synthesized and are ultimately equally versatile and significant at the nanoscale level; however, reports concerning ravel structures, which are highly entwined new topological species, are extremely rare and fraught with tremendous synthesis challenges. To solve the synthesis problem, a tetrapodontic pyridine ligand L1 with two types of olefinic bond units and two Cp*M-based building blocks (E1, M=Rh; E2, M=Ir) featuring large conjugated planes was prepared to perform the self-assembly. Two unprecedented [5+10] icosanuclear molecular 4-ravels containing four crossings were obtained by parallel-displaced π⋅⋅⋅π interactions in a single-step strategy.

The Selective CO Adsorption and Photothermal Conversion Study of an Azo-Based Cobalt-MOF Material.

A new metal-organic framework (MOF), [Co(L)(azpy)] (compound , HL = 5-(pyridin-4-ylmethoxy)-isophthalic acid, azpy = 4,4'-azopyridine), was synthesized by a solvothermal method and further characterized by elemental analysis, IR spectra, thermogravimetric analysis, single-crystal and powder X-ray diffraction. The X-ray single-crystal diffraction analysis for compound indicated that two L2 ligands connected to two cobalt atoms resulted in a macrocycle structure. Through a series of adsorption tests, we found that compound exhibited a high capacity of CO, and the adsorption capacity could reach 30.

Size-Induced Highly Selective Synthesis of Organometallic Rectangular Macrocycles and Heterometallic Cage Based on Half-Sandwich Rhodium Building Block.

The controlled synthesis of organometallic supramolecular macrocycles cages remains interesting and challenging work in the field of supramolecular chemistry. Here, two tetranuclear rectangular macrocycles and an octuclear cage were designed and synthesized utilizing a rigid and functionalized pillar linker, 2,6-bis(pyridin-4-yl)-1,7-dihydrobenzo [1,2-d:4,5-d']diimidazole (BBI4PY) based on three half-sandwich rhodium building blocks bearing different sizes. X-ray crystallography in combination with H NMR spectroscopy elucidated that the two building blocks with shorter spacers only result in rectangular macrocycles.

Selective synthesis and structural transformation between a molecular ring-in-ring architecture and an abnormal trefoil knot.

The synthesis of complicated supramolecular architectures and the study of their reversible structural transformations remains a fascinating challenge in the field of supramolecular chemistry. Herein, two types of novel coordination compounds, a non-intertwined ring-in-ring assembly and an abnormal trefoil knot were constructed from a strategically selected Cp*Rh building block and a semi-rigid ,'-bis(4-pyridylmethyl)diphthalic diimide ligand coordination-driven self-assembly. Remarkably, the reversible transformation between the abnormal trefoil knot and the ring-in-ring assembly or the corresponding tetranuclear macrocycle could be achieved by the synergistic effects of Ag ion coordination and alteration of the solvent.

Self-Assembly of Molecular Figure-Eight Knots Induced by Quadruple Stacking Interactions.

Molecular figure-eight knot (notation: 4) is extremely rare and presents great synthetic challenge due to its essentially complicated entanglement. To solve this synthetic problem, a quadruple stacking strategy was developed. Herein, we report the efficient self-assembly of figure-eight knots induced by quadruple stacking interactions, through the combination of four carefully selected naphthalenediimide (NDI)-based pyridyl ligands and Cp*Rh building blocks bearing large conjugated planes in a single-step strategy.

Highly stable 3D porous HMOF with enhanced catalysis and fine color regulation by the combination of d- and p-ions when compared with those of its monometallic MOFs.

In this study, two new monometallic organic frameworks (MOFs), namely {[ZnL(NMP)(HO)]·HO} (1) and {[PbL(HO)]·HO} (2), were synthesized for the first time by a new bifunctional N,O-containing 2-(1H-tetrazol-5-yl)terephthalic acid (HL) ligand. Then, based on the HSAB principle, another porous Pb-Zn heterometallic organic framework (HMOF), namely {[PbZnL(HO)]·0.5NMP·HO} (3), was successfully obtained for the first time by combining Pb(ii) and Zn(ii) ions with HL.

Coordination-driven self-assembly of a molecular figure-eight knot and other topologically complex architectures.

Over the past decades, molecular knots and links have captivated the chemical community due to their promising mimicry properties in molecular machines and biomolecules and are being realized with increasing frequency with small molecules. Herein, we describe how to utilize stacking interactions and hydrogen-bonding patterns to form trefoil knots, figure-eight knots and [2]catenanes. A transformation can occur between the unique trefoil knot and its isomeric boat-shaped tetranuclear macrocycle by the complementary concentration effect.

Controllable assembly of rectangular macrocycles bearing different numbers of unsaturated sites based on half-sandwich iridium fragments.

A series of hexanuclear rectangular macrocycles were designed and synthesized by utilizing multifunctional pyrazine-derived (pyrazine-2,3-diamine (H4L1)) and quinoxaline-derived ligands (2,3-dihydroxy-quinoxaline (H2L2)) featuring two monodentate sites and one pair of chelating sites. X-ray crystallography in combination with 1H NMR spectroscopy elucidated that both half-sandwich iridium diimine and dihydroxy moieties are located on either side of the rectangular macrocycles, making them centrosymmetric. Thereby, the prepared diimine-functionalised complexes were found to have unsaturated metal sites on account of their strongly bound Ir-N-C-C-N arrangement.