A chiral tetracarboxylic acid ligand, HL, incorporating the (S)-(+)-2-methylpiperazine moiety in its middle, solvothermally forms a homochiral Cu(II) framework, {[Cu(L)(HO)]·(4DMF)(4HO)} (LCu). It forms a non-interpenetrated structure consisting of [Cu(COO)] paddle-wheel secondary bonding units (SBUs) with NbO topology. Interestingly, the framework LCu exhibits excellent ferroelectric properties. It shows a remnant polarization (Pr) of ∼3.5 μC cm and a coercive field (E) of ∼12 kV cm with a distinct electric hysteresis loop. Dielectric studies of LCu reveal almost frequency-independent behavior with a dielectric constant (ε) of ∼42 and a low dielectric loss (tan δ) of ∼0.04 up to 10 Hz, for potential use in high-frequency applications. In addition, activated framework LCu' having uncoordinated metal sites acts as an efficient heterogeneous catalyst in the three-component coupling of amines, aldehydes, and alkynes, as well as in Pechmann reactions of phenols with β-ketoesters.
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http://dx.doi.org/10.1021/acs.inorgchem.7b00342 | DOI Listing |
J Am Soc Mass Spectrom
March 2024
Sorbonne Université, Institut Parisien de Chimie Moléculaire (IPCM), 75005 Paris, France.
Angew Chem Int Ed Engl
July 2023
Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, Tamilnadu, India.
The cyclodimerization (homochiral- and heterochiral-) of monomeric units for the construction of stereodefined polycyclic systems is a powerful strategy in both biosynthesis and biomimetic synthesis. Herein we have discovered and developed a Cu - catalyzed, biomimetic, diastereoselective tandem cycloisomerization-[3+2] cyclodimerization of 1-(indol-2-yl)pent-4-yn-3-ol. This novel strategy operates under very mild conditions, providing access to structurally unprecedented dimeric tetrahydrocarbazoles fused to a tetrahydrofuran unit in excellent yields of the products.
View Article and Find Full Text PDFInorg Chem
October 2021
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, People's Republic of China.
Natural gas (NG) and ethylene (CH) are two raw materials of significant value for manufacturing versatile fine chemicals and/or polymers, and thus the development of solid adsorbing agents such as metal-organic frameworks (MOFs) applied to their depuration is very crucial but remains highly challenging. In this research, we designed and synthesized a ligand containing mixed N and O coordination donors, which was solvothermally assembled with Cu(II) ions to generate a microporous MOF. X-ray crystallography revealed that the title MOF incorporates one-dimensional (1D) homochiral helical chains that are datively cross-linked to form open channels in the three-periodic coordination framework.
View Article and Find Full Text PDFChirality
October 2021
Institute Physical and Chemistry Materials of Strasbourg, CNRS University of Strasbourg, Strasbourg, France.
We report on the polymerization/depolymerization of chiral metallo-supramolecular assembly by Cu /Cu redox change. By combining a monotopic enantiopure ligand with a ditopic ligand of opposite configuration, ML -type complexes are generated with chiral self-recognition or self-discrimination depending on the oxidation state of copper. In presence of Cu , the formation of heterochiral complexes is favored, thus generating dinuclear species whereas Cu advocates for the formation of homochiral species, namely, a mixture of mononuclear species and metallo-supramolecular polymeric species.
View Article and Find Full Text PDFChemistry
December 2021
Institute of Chemical Research of Catalonia (ICIQ) and the Barcelona, Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007, Tarragona, Spain.
TAMOF-1, a homochiral metal-organic framework (MOF) constructed from an amino acid derivative and Cu(II), was investigated as a heterogeneous catalyst in kinetic resolutions involving the ring opening of styrene oxide with a set of anilines. The branched products generated from the ring opening of styrene oxide with anilines and the unreacted epoxide were obtained with moderately high enantiomeric excesses. The linear product arising from the attack on the non-benzylic position of styrene oxide underwent a second kinetic resolution by reacting with the epoxide, resulting in an amplification of its final enantiomeric excess and a concomitant formation of an array of isomeric aminodiols.
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