Luminescent Polymorphic Aggregates of Trinuclear Cu(I)-pyrazolate Tuned by Intertrimeric Cu···NPy Weak Coordination Bonds

2021 ◽  
Author(s):  
Shun-Ze Zhan ◽  
Wei Chen ◽  
Ji Zheng ◽  
Seik Weng Ng ◽  
Dan Li
Keyword(s):  
Coordination Bonds ◽  
Weak Coordination

Five luminescent polymorphic aggregates of trinuclear Cu(I)-pyrazolate, namely [anti-Cu3L3]2 (1), [syn-Cu3L3·C2H5OH]2 (2), [anti-Cu3L3·C2H5OH]n (3), [anti-Cu3L3·0.5C7H8]n (4) and [syn-Cu3L3·C8H10]n (5) (HL = 4-(pyridin-4-ylthio)-3,5-dimethyl-1H-pyrazole), were reported. The trimeric Cu3L3 fragments present syn-...

A silicone elastomer with optimized and tunable mechanical strength and self-healing ability based on strong and weak coordination bonds

2020 ◽  
Vol 11 (24) ◽  
pp. 4047-4057 ◽  
Author(s):  
Ming Tian ◽  
Hongli Zuo ◽  
Jie Wang ◽  
Nanying Ning ◽  
Bing Yu ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Mechanical Strength ◽  
Silicone Elastomer ◽  
Self Healing ◽  
Coordination Bonds ◽  
Weak Coordination

A self-healable silicone elastomer is fabricated based on the synergistic effect of strong and weak coordination bonds.

scholarly journals Multifunctionality in Polymer Networks by Dynamic of Coordination Bonds

2021 ◽  
Vol 222 (3) ◽  
pp. 2170005
Author(s):  
Pengfei Zhang ◽  
Andraž Rešetič ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Polymer Networks ◽  
Coordination Bonds

Zwitterionic and hydrophilic polyelectrolyte/metal ion anti-fouling layers via covalent and coordination bonds for reverse osmosis membranes

2021 ◽  
Author(s):  
Mengying Jiang ◽  
Li-Ye Chen ◽  
Qian Zou ◽  
Siwei Xiong ◽  
Peigen Fu ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Metal Ion ◽  
Sewage Treatment ◽  
Membrane Technology ◽  
Seawater Desalination ◽  
Ro Membrane ◽  
Coordination Bonds ◽  
Reverse Osmosis Membranes

Reverse osmosis (RO) membrane technology, as an effective and eco-friendly method, has been widely used for seawater desalination and sewage treatment. However, RO membranes inevitably suffer serious organic and biological...

scholarly journals A bipyridine-ligated zinc(II) complex with bridging flavonolate ligation: synthesis, characterization, and visible-light-induced CO release reactivity

2017 ◽  
Vol 73 (9) ◽  
pp. 703-709 ◽  
Author(s):  
Shayne Sorenson ◽  
Marina Popova ◽  
Atta M. Arif ◽  
Lisa M. Berreau
Keyword(s):  
Visible Light ◽  
Ligand Exchange ◽  
Distorted Octahedral Geometry ◽  
Conductivity Measurements ◽  
Bidentate Coordination ◽  
H Nmr ◽  
Distorted Octahedral ◽  
Spectroscopic Identification ◽  
Synthetic Models ◽  
Weak Coordination

Metal–flavonolate compounds are of significant current interest as synthetic models for quercetinase enzymes and as bioactive compounds of importance to human health. Zinc–3-hydroxyflavonolate compounds, including those of quercetin, kampferol, and morin, generally exhibit bidentate coordination to a single ZnII center. The bipyridine-ligated zinc–flavonolate compound reported herein, namely bis(μ-4-oxo-2-phenyl-4H-chromen-3-olato)-κ3 O 3:O 3,O 4;κ3 O 3,O 4:O 3-bis[(2,2′-bipyridine-κ2 N,N′)zinc(II)] bis(perchlorate), {[Zn2(C15H9O3)2(C10H8N2)2](ClO4)2} n , (1), provides an unusual example of bridging 3-hydroxyflavonolate ligation in a dinuclear metal complex. The symmetry-related ZnII centers of (1) exhibit a distorted octahedral geometry, with weak coordination of a perchlorate anion trans to the bridging deprotonated O atom of the flavonolate ligand. Variable-concentration conductivity measurements provide evidence that, when (1) is dissolved in CH3CN, the complex dissociates into monomers. 1H NMR resonances for (1) dissolved in d 6-DMSO were assigned via HMQC to the H atoms of the flavonolate and bipyridine ligands. In CH3CN, (1) undergoes quantitative visible-light-induced CO release with a quantum yield [0.004 (1)] similar to that exhibited by other mononuclear zinc–3-hydroxyflavonolate complexes. Mass spectroscopic identification of the [(bpy)2Zn(O-benzoylsalicylate)]+ ion provides evidence of CO release from the flavonol and of ligand exchange at the ZnII center.

Competition between coordination bonds and hydrogen bonding interactions in solvatomorphs of copper(II), cadmium(II) and cobalt(II) complexes with 2,2′-bipyridyl and acetate

2019 ◽  
Vol 234 (2) ◽  
pp. 119-128 ◽  
Author(s):  
José Antônio do Nascimento Neto ◽  
Cameron Capeletti da Silva ◽  
Leandro Ribeiro ◽  
Ana Karoline Silva Mendanha Valdo ◽  
Felipe Terra Martins
Keyword(s):  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Organic Molecules ◽  
Energy Difference ◽  
Water Molecules ◽  
Coordination Numbers ◽  
Lattice Water ◽  
Hydrogen Bonding Interactions ◽  
Metal Organic ◽  
Coordination Bonds

Abstract The delicate balance among conformation, coordination bonds and hydrogen bonding has been probed in solvatomorphs of known metal-organic molecules synthesised from copper(II), cadmium(II) and cobalt(II) with acetate (OAc) and 2,2′-bipyridine (bipy). The Cu(OAc)2(bipy) complex, isolated as a pentahydrate, has the acetate ligands oriented to opposite sides of the coordination square plane. DFT calculations show the energy difference between this structure and a syn form amount to approximately 16 kJ/mol. The presence of lattice water enables the formation of O–H···O hydrogen bonds with the acetate ligands. Different coordination numbers and energies are found as a function of the number of water molecules co-crystallising in the Cd(OAc)2(bipy)(OH2)·3H2O and [Co(OAc)(bipy)2](OAc)·3H2O complexes.

scholarly journals Infrastructure Development in Papua: Features and Challenges

2019 ◽  
Vol 3 (3) ◽  
pp. 225
Author(s):  
Fadhli Zul Fauzi ◽  
A. A. Gede Brahmantya Murti ◽  
Laili Alfiati Imamah ◽  
Nimas Hapsari
Keyword(s):  
Qualitative Method ◽  
Development Process ◽  
Regional Government ◽  
Infrastructure Development ◽  
Cultural Issues ◽  
Study Approach ◽  
Study Results ◽  
Weak Coordination ◽  
Government Institution

This article aims to examine the issue of infrastructure development in Papua Province, Indonesia. This article specifically discusses the problems confronted during the process of infrastructure development in Jayapura and the challenges in expanding them. The method used in this study is the qualitative method with a case study approach, wherein the infrastructure development case selected is the Papua Bangkit Stadium and Holtekamp Bridge located in Jayapura. Both infrastructure development cases serve as sample cases that show the extent of infrastructure development impact in Papua, and the issues that were confronted, starting from the development process up to the expansion. The study results indicate that although previous studies have shown positive correlation between development and welfare, in reality, there are several problems occurring in Papua’s infrastructure development. Preparedness of human resources, cultural issues, and weak coordination between every level of regional government institution, these are the main problems in Papua’s infrastructure development. This article is expected to assist in resolving the issues found in Papua’s infrastructure development, and to provide recommendations for resolving those issues.

scholarly journals Palladium-Catalyzed [3+2] Cycloaddition via Two-Fold 1,3-C(sp3)−H Activation

2020 ◽  
Author(s):  
Hojoon Park ◽  
jin-quan yu
Keyword(s):  
Functional Groups ◽  
Sulfonic Acid ◽  
Cycloaddition Reaction ◽  
Wide Range ◽  
Leaving Group ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
Overall Efficiency ◽  
Weak Coordination ◽  
Single Reaction

<div>Cycloaddition reactions provide an expeditious route to construct ring systems in a highly convergent and stereoselective manner. For a typical cycloaddition reaction to occur, however, the installation of multiple reactive functional groups (π-bonds, leaving group, etc.) are required within the substrates, compromising the overall efficiency or scope of the cycloaddition reaction. Here, we report a palladium-catalyzed [3+2] reaction that utilizes C(sp<sup>3</sup>)–H activation to generate the three-carbon unit for formal cycloaddition with maleimides. We implemented a strategy where the initial C(sp<sup>3</sup>)–H activation/olefin insertion would trigger a relayed, second remote C(sp<sup>3</sup>)–H activation to complete a formal [3+2] cycloaddition. The diastereoselectivity profile of this reaction resembles that of a typical pericyclic cycloaddition reaction in that the relationships between multiple stereocenters are exquisitely controlled in a single reaction. The key to success was the use of weakly coordinating amides as the directing group, as undesired Heck or alkylation pathways were preferred with other types of directing groups. The use of the pyridine-3-sulfonic acid ligands is critical to enable C(sp<sup>3</sup>)–H activation directed by this weak coordination. The method is compatible with a wide range of amide substrates, including lactams, which lead to novel spiro-bicyclic products. The [3+2] product is also shown to undergo a reductive desymmetrization process to access chiral cyclopentane bearing multiple stereocenters with excellent enantioselectivity.</div>

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