Synthesis and Characterization of Self-Assembled Nanoscopic Metallarectangles Capable of Binding Fullerenes with Size-Selective Responses

Two new metallarectangles, <b>4</b> and <b>5</b>, were obtained from the self-assembly of areneruthenium-based molecular clips <b>2</b> and <b>3</b> with a new dipyridyl donor ligand <b>1</b> containing a diamide core and ethynyl spacers. The metallarectangles were characterized by multinuclear NMR, electrospray ionization mass spectrometry, and UV–vis spectroscopy, and the molecular structure of <b>4</b> was unambiguously determined by single-crystal X-ray diffraction analysis. Because of the presence of an extended π-electron aromatic surface, the tetracene-containing molecular rectangle <b>5</b> was capable of binding C₆₀ and C₇₀ fullerenes as quantified by UV–vis, emission, and ¹H NMR experiments, providing an example of a supramolecular host capable of recognizing large guest molecules

Synthesis and Characterization of Self-Assembled Nanoscopic Metallarectangles Capable of Binding Fullerenes with Size-Selective Responses

Two new metallarectangles, <b>4</b> and <b>5</b>, were obtained from the self-assembly of areneruthenium-based molecular clips <b>2</b> and <b>3</b> with a new dipyridyl donor ligand <b>1</b> containing a diamide core and ethynyl spacers. The metallarectangles were characterized by multinuclear NMR, electrospray ionization mass spectrometry, and UV–vis spectroscopy, and the molecular structure of <b>4</b> was unambiguously determined by single-crystal X-ray diffraction analysis. Because of the presence of an extended π-electron aromatic surface, the tetracene-containing molecular rectangle <b>5</b> was capable of binding C₆₀ and C₇₀ fullerenes as quantified by UV–vis, emission, and ¹H NMR experiments, providing an example of a supramolecular host capable of recognizing large guest molecules

Selective Synthesis of Ruthenium(II) Metalla[2]Catenane via Solvent and Guest-Dependent Self-Assembly

The coordination-driven self-assembly of an anthracene-functionalized ditopic pyridyl donor and a tetracene-based dinuclear Ru­(II) acceptor resulted in an interlocked metalla[2]­catenane, [M₂L₂]₂, in methanol and a corresponding monorectangle, [M₂L₂], in nitromethane. Subsequently, guest template, solvent, and concentration effects allowed the self-assembly to be reversibly fine-tuned among monorectangle and catenane structures

Coordination-Driven Self-Assembly of 2D-Metallamacrocycles Using a New Carbazole-Based Dipyridyl Donor: Synthesis, Characterization, and C₆₀ Binding Study

A new carbazole-based 90° dipyridyl donor 3,6-di­(4-pyridylethynyl)­carbazole (<b>L</b>) containing carbazole-ethynyl functionality is synthesized in reasonable yield using the Sonagashira coupling reaction. Multinuclear NMR, electrospray ionization-mass spectrometry (ESI-MS), including single crystal X-ray diffraction analysis characterized this 90° building unit. The stoichiometry combination of <b>L</b> with several Pd­(II)/Pt­(II)-based 90° acceptors (<b>1a</b>–<b>1d</b>) yielded [2 + 2] self-assembled metallacycles (<b>2a</b>–<b>2d</b>) under mild conditions in quantitative yields [<b>1a</b> = <i>cis</i>-(dppf)­Pd­(OTf)₂; <b>1b</b> = <i>cis</i>-(dppf)­Pt­(OTf)₂; <b>1c</b> = <i>cis</i>-(tmen)­Pd­(NO₃)₂; <b>1d</b> = 3,6-bis­{<i>trans</i>-Pt­(CC)­(PEt₃)₂(NO₃)}­carbazole]. All these macrocycles were characterized by various spectroscopic techniques, and the molecular structure of <b>2a</b> was unambiguously determined by single crystal X-ray diffraction analysis. Incorporation of ethynyl functionality to the carbazole backbone causes the resulted macrocycles (<b>2a</b>–<b>2d</b>) to be π-electron rich and thereby exhibit strong emission characteristics. The macrocycle <b>2a</b> has a large internal concave aromatic surface. The fluorescence quenching study suggests that <b>2a</b> forms a ∼1:1 complex with C₆₀ with a high association constant of <i>K</i>_sv = 1.0 × 10⁵ M^–1

Coordination-Driven Self-Assembly of 2D-Metallamacrocycles Using a New Carbazole-Based Dipyridyl Donor: Synthesis, Characterization, and C₆₀ Binding Study

A new carbazole-based 90° dipyridyl donor 3,6-di­(4-pyridylethynyl)­carbazole (<b>L</b>) containing carbazole-ethynyl functionality is synthesized in reasonable yield using the Sonagashira coupling reaction. Multinuclear NMR, electrospray ionization-mass spectrometry (ESI-MS), including single crystal X-ray diffraction analysis characterized this 90° building unit. The stoichiometry combination of <b>L</b> with several Pd­(II)/Pt­(II)-based 90° acceptors (<b>1a</b>–<b>1d</b>) yielded [2 + 2] self-assembled metallacycles (<b>2a</b>–<b>2d</b>) under mild conditions in quantitative yields [<b>1a</b> = <i>cis</i>-(dppf)­Pd­(OTf)₂; <b>1b</b> = <i>cis</i>-(dppf)­Pt­(OTf)₂; <b>1c</b> = <i>cis</i>-(tmen)­Pd­(NO₃)₂; <b>1d</b> = 3,6-bis­{<i>trans</i>-Pt­(CC)­(PEt₃)₂(NO₃)}­carbazole]. All these macrocycles were characterized by various spectroscopic techniques, and the molecular structure of <b>2a</b> was unambiguously determined by single crystal X-ray diffraction analysis. Incorporation of ethynyl functionality to the carbazole backbone causes the resulted macrocycles (<b>2a</b>–<b>2d</b>) to be π-electron rich and thereby exhibit strong emission characteristics. The macrocycle <b>2a</b> has a large internal concave aromatic surface. The fluorescence quenching study suggests that <b>2a</b> forms a ∼1:1 complex with C₆₀ with a high association constant of <i>K</i>_sv = 1.0 × 10⁵ M^–1

Coordination-Driven Self-Assembly and Anticancer Potency Studies of Arene–Ruthenium-Based Molecular Metalla-Rectangles

The two new large molecular metalla-rectangles <b>6</b> and <b>8</b> were obtained by the reaction of the two different arene–ruthenium acceptors [Ru₂(<i>p-</i>cymene)₂(μ-η⁴-C₂O₄)­Cl₂] (<b>2</b>) and [Ru₂(<i>p-</i>cymene)₂(donq)­(Cl)₂] (donq = 5,8-dioxido-1,4-naphthoquinonato) (<b>4</b>) with a symmetrical <i>N</i>,<i>N</i>′-bis­(4-(pyridin-4-ylethynyl)­phenyl)­terephthalamide (<b>1</b>) donor ligand. Both metalla-rectangles were isolated in good yields as triflate salts and were characterized by multinuclear NMR, ESI–MS, and UV–vis spectroscopy. X-ray crystallography of <b>6</b> confirmed a molecular metalla-rectangle. The cytotoxicities of metalla-rectangles <b>6</b>–<b>9</b> were established in SK-hep-1 (liver cancer), AGS (gastric cancer), and HCT-15 (colorectal cancer) human cancer cell lines. The cytotoxicity of metalla-rectangle <b>8</b> was found to be considerably stronger against all cancer cell lines, even much more effective than the well-known anticancer drugs doxorubicin and cisplatin. In addition, expressions of APC and p53, colorectal cancer suppressor genes, were significantly increased following exposure to the metalla-rectangle <b>8</b>

Selective Synthesis of Molecular Borromean Rings: Engineering of Supramolecular Topology via Coordination-Driven Self-Assembly

Molecular Borromean rings (BRs) is one of the rare topology among interlocked molecules. Template-free synthesis of BRs via coordination-driven self-assembly of tetracene-based Ru­(II) acceptor and ditopic pyridyl donors is reported. NMR and single-crystal XRD analysis observed sequential transformation of a fully characterized monomeric rectangle to molecular BRs and vice versa. Crystal structure of BRs revealed that the particular topology was enforced by the appropriate geometry of the metallacycle and multiple parallel-displaced π–π interactions between the donor and tetracene moiety of the acceptor. Computational studies based on density functional theory also supported the formation of BRs through dispersive intermolecular interactions in solution

Banking performance’ determinants

У статті розглянуто фактори впливу на ефективність банківського бізнесу. З позиції необхідності управління ефективністю банківського бізнесу запропоновано внутрішні фактори розглядати як сукупність статусних характеристик банку та характеристик його бізнес-моделі.The article deals with banking performance’s determinants. In context of banking performance management its proposed internal factors to consider as a set of status characteristics and the characteristics of the bank's business model

Formation of [3]Catenanes from 10 Precursors via Multicomponent Coordination-Driven Self-Assembly of Metallarectangles

We describe the formation of a suite of [3]­catenanes via multicomponent coordination-driven self-assembly and host–guest complexation of a rectangular scaffold comprising a 90° Pt-based acceptor building block with a pseudorotaxane bis­(pyridinium)­ethane/dibenzo-24-crown-8 linear dipyridyl ligand and three dicarboxylate donors. The doubly threaded [3]­catenanes are formed from a total of 10 molecular components from four unique species. Furthermore, the dynamic catenation process is reversible and can be switched off and on in a controllable manner by successive addition of KPF₆ and 18-crown-6, as monitored by ¹H and ³¹P NMR spectroscopy

A Unique Non-catenane Interlocked Self-Assembled Supramolecular Architecture and Its Photophysical Properties

A novel, interlocked, self-assembled (M₂L₂)₂ molecular architecture was constructed from an arene-Ru acceptor and a 1,4-di(pyridin-4-yl)buta-1,3-diyne donor. Two M₂L₂ units, with cavities of ∼7.21 Å, spontaneously interlock, with one unit encapsulating a twin in a non-catenane fashion. The dimeric host–guest complex thus formed is unique among two-dimensional self-assemblies and is stabilized by π–π interactions between the M₂L₂ units