scholarly journals Thermodynamic synthesis of solution processable ladder polymers

2016 ◽  
Vol 7 (2) ◽  
pp. 881-889 ◽  
Author(s):  
Jongbok Lee ◽  
Bharath Bangalore Rajeeva ◽  
Tianyu Yuan ◽  
Zi-Hao Guo ◽  
Yen-Hao Lin ◽  
...  
Keyword(s):  
Olefin Metathesis ◽  
Thermodynamic Control ◽  
Ladder Polymers ◽  
Ladder Polymer ◽  
Solution Processable

The synthesis of a carbazole-derived, well-defined ladder polymer was achieved under thermodynamic control by employing reversible ring-closing olefin metathesis.

Donor–acceptor conjugated ladder polymer via aromatization-driven thermodynamic annulation

2018 ◽  
Vol 9 (13) ◽  
pp. 1603-1609 ◽  
Author(s):  
Jongbok Lee ◽  
Alexander J. Kalin ◽  
Chenxu Wang ◽  
Julia T. Early ◽  
Mohammed Al-Hashimi ◽  
...  
Keyword(s):  
Olefin Metathesis ◽  
High Efficiency ◽  
Donor Acceptor ◽  
Ladder Polymers ◽  
Ladder Polymer

The construction of coplanar conjugated ladder polymers featuring alternating donor–acceptor units has been achieved in high efficiency using ring-closing olefin metathesis.

scholarly journals Tailoring π-conjugation and vibrational modes to steer on-surface synthesis of pentalene-bridged ladder polymers

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Bruno de la Torre ◽  
Adam Matěj ◽  
Ana Sánchez-Grande ◽  
Borja Cirera ◽  
Benjamin Mallada ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Materials Science ◽  
Second Step ◽  
Vibrational Modes ◽  
Force Microscopy ◽  
Synthetic Strategy ◽  
Atomic Force ◽  
Structures And Properties ◽  
Ladder Polymers ◽  
Ladder Polymer

Abstract The development of synthetic strategies to engineer π-conjugated polymers is of paramount importance in modern chemistry and materials science. Here we introduce a synthetic protocol based on the search for specific vibrational modes through an appropriate tailoring of the π-conjugation of the precursors, in order to increase the attempt frequency of a chemical reaction. First, we design a 1D π-conjugated polymer on Au(111), which is based on bisanthene monomers linked by cumulene bridges that tune specific vibrational modes. In a second step, upon further annealing, such vibrational modes steer the twofold cyclization reaction between adjacent bisanthene moieties, which gives rise to a long pentalene-bridged conjugated ladder polymer featuring a low bandgap. In addition, high resolution atomic force microscopy allows us to identify by atomistic insights the resonance form of the polymer, thus confirming the validity of the Glidewell and Lloyd´s rules for aromaticity. This on-surface synthetic strategy may stimulate exploiting previously precluded reactions towards π-conjugated polymers with specific structures and properties.

New phenazine-containing ladder polymer of intrinsic microporosity from a spirobisindane-based AB-type monomer

RSC Advances ◽  
2016 ◽  
Vol 6 (83) ◽  
pp. 79625-79630 ◽  
Author(s):  
Bader Ghanem ◽  
Fahd Alghunaimi ◽  
Nasser Alaslai ◽  
Xiaohua Ma ◽  
Ingo Pinnau
Keyword(s):  
Polymer Of Intrinsic Microporosity ◽  
Ladder Polymer ◽  
Solution Processable ◽  
Intrinsic Microporosity

A new solution-processable ladder polymer (PSBI-AB) of intrinsic microporosity with dibenzodioxane linkages and bis(phenazine) units was designed and synthesized by self-polymerization of an AB-type monomer containing both catechol and aromatic dichloride groups.

Comparison of gas transport and sorption in the ladder polymer BBL and some semi-ladder polymers

Polymer ◽  
1999 ◽  
Vol 40 (20) ◽  
pp. 5655-5664 ◽  
Author(s):  
Catherine M. Zimmerman ◽  
William J. Koros
Keyword(s):  
Gas Transport ◽  
Ladder Polymers ◽  
Ladder Polymer

Solution-Processable Porous Nanoparticles of a Conjugated Ladder Polymer Network

2020 ◽  
Vol 53 (3) ◽  
pp. 922-928 ◽  
Author(s):  
Alexander J. Kalin ◽  
Sai Che ◽  
Chenxu Wang ◽  
Anthony U. Mu ◽  
E. Meir Duka ◽  
...  
Keyword(s):  
Polymer Network ◽  
Porous Nanoparticles ◽  
Ladder Polymer ◽  
Solution Processable

Switching of the conformational flexibility of a diazacyclooctane-containing ladder polymer by coordination and elimination of a Lewis acid

2020 ◽  
Vol 11 (2) ◽  
pp. 236-240 ◽  
Author(s):  
Fumitaka Ishiwari ◽  
Momoko Ofuchi ◽  
Keiki Inoue ◽  
Yoshihisa Sei ◽  
Takanori Fukushima
Keyword(s):  
Lewis Acid ◽  
Main Chain ◽  
Conformational Flexibility ◽  
Ladder Polymers ◽  
Ladder Polymer

We report the first system of ladder polymers capable of interconversion between rigid and flexible conformations by coordination and elimination of a Lewis acid (BPh2Cl) on diazacyclooctane units in the main chain.

Computational Predictions of the Tensile and Compressive Properties of Rigid-Rod Polymers

1988 ◽  
Vol 134 ◽  
Author(s):  
Scott G. Wierschke
Keyword(s):  
Failure Modes ◽  
Plane Deformation ◽  
Phenyl Group ◽  
Orbital Method ◽  
Tension And Compression ◽  
Ladder Polymers ◽  
Weak Points ◽  
Rigid Rod ◽  
Ladder Polymer ◽  
Bending Failure

ABSTRACTThe Austin Model 1 (AM1) semiempirical molecular orbital method has been used to calculate tensile moduli and molecular tensile and compressive deformation for several rigid-rod polymers and a graphite model. The calculated moduli are an improvement over previous Modified Neglect of Differential Overlap (MNDO) calculations. These are the ultimate moduli or the perfectly aligned bulk systems. By analyzing the deformation of polymer molecules in tension and compression, the failure modes and weak points in the molecules can be determined. In compression, all the heterocyclic rigid-rod polymers exhibit a “bending” failure mode. In tension and compression, the phenyl group in the rods undergoes in-plane deformation more easily than the heterocyclic moiety, thus causing a lowering of the modulus. The hypothetical “ladder” polymer, polyacene, shows higher tensile and compressive resistance than any of the rods, suggesting that further study into the ladder polymers is warranted.

Capacitive conjugated ladder polymers for fast-charge and -discharge sodium-ion batteries and hybrid supercapacitors

2019 ◽  
Vol 7 (36) ◽  
pp. 20891-20898 ◽  
Author(s):  
Yuan Chen ◽  
Hongyang Li ◽  
Mi Tang ◽  
Shuming Zhuo ◽  
Yanchao Wu ◽  
...  
Keyword(s):  
High Capacity ◽  
Rate Capability ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Fast Charge ◽  
Hybrid Supercapacitors ◽  
Ladder Polymers ◽  
Ladder Polymer

A novel conjugated ladder polymer is developed, showing high capacity and rate capability in organic sodium-ion batteries and hybrid supercapacitors.

Stereodivergent Alkyne Hydrofluorination Using a Simple Practical Reagent

2020 ◽  
Author(s):  
Rui Guo ◽  
Xiaotian Qi ◽  
Hengye Xiang ◽  
Paul Geaneoates ◽  
Ruihan Wang ◽  
...  
Keyword(s):  
Bond Formation ◽  
Biologically Active ◽  
Dft Studies ◽  
Thermodynamic Control ◽  
Important Goal ◽  
Peptide Bonds ◽  
Metal Free ◽  
Vinyl Cation ◽  
E And Z Isomers ◽  
Vinyl Fluorides

Vinyl fluorides play an important role in drug development as they serve as bioisosteres for peptide bonds and are found in a range of biologically active molecules. The discovery of safe, general and practical procedures to prepare vinyl fluorides remains an important goal and challenge for synthetic chemistry. Here we introduce an inexpensive and easily-handled reagent and report simple, scalable, and metal-free protocols for the regioselective and stereodivergent hydrofluorination of alkynes to access both the E and Z isomers of vinyl fluorides. These conditions were suitable for a diverse collection of alkynes, including several highly-functionalized pharmaceutical derivatives. Mechanistic and DFT studies support C–F bond formation through a vinyl cation intermediate, with the (E)- and (Z)-hydrofluorination products forming under kinetic and thermodynamic control, respectively.<br>

Catalytic Carbonyl-Olefin Metathesis of Aliphatic Ketones: Iron(III) HomoDimers as Lewis Acidic Superelectrophiles

2018 ◽  
Author(s):  
Haley Albright ◽  
Paul S. Riehl ◽  
Christopher C. McAtee ◽  
Jolene P. Reid ◽  
Jacob R. Ludwig ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Olefin Metathesis ◽  
Acid Activation ◽  
Lewis Acid Catalysts ◽  
Distinct Mode ◽  
Aliphatic Ketones ◽  
Carbon Carbon Bond ◽  
Metathesis Reactions ◽  
Acid Catalyzed

<div>Catalytic carbonyl-olefin metathesis reactions have recently been developed as a powerful tool for carbon-carbon bond</div><div>formation. However, currently available synthetic protocols rely exclusively on aryl ketone substrates while the corresponding aliphatic analogs remain elusive. We herein report the development of Lewis acid-catalyzed carbonyl-olefin ring-closing metathesis reactions for aliphatic ketones. Mechanistic investigations are consistent with a distinct mode of activation relying on the in situ formation of a homobimetallic singly-bridged iron(III)-dimer as the active catalytic species. These “superelectrophiles” function as more powerful Lewis acid catalysts that form upon association of individual iron(III)-monomers. While this mode of Lewis acid activation has previously been postulated to exist, it has not yet been applied in a catalytic setting. The insights presented are expected to enable further advancement in Lewis acid catalysis by building upon the activation principle of “superelectrophiles” and broaden the current scope of catalytic carbonyl-olefin metathesis reactions.</div>

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