scholarly journals Supramolecular Systems Containing B–N Frustrated Lewis Pairs of Tris(pentafluorophenyl)borane and Triphenylamine Derivatives

2021 ◽  
Vol 03 (02) ◽  
pp. 174-183
Author(s):  
P. Chidchob ◽  
S. A. H. Jansen ◽  
S. C. J. Meskers ◽  
E. Weyandt ◽  
N. P. van Leest ◽  
...  
Keyword(s):  
Materials Science ◽  
Supramolecular Polymers ◽  
Frustrated Lewis Pairs ◽  
Paramagnetic Resonance ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Noncovalent Polymers ◽  
Electron Paramagnetic ◽  
Supramolecular Polymerization ◽  
Lewis Pairs

The introduction of a chemical additive to supramolecular polymers holds high potential in the development of new structures and functions. In this regard, various donor- and acceptor-based molecules have been applied in the design of these noncovalent polymers. However, the incorporation of boron–nitrogen frustrated Lewis pairs in such architectures is still rare despite their many intriguing properties in catalysis and materials science. The limited choices of suitable boron derivatives represent one of the main limitations for the advancement in this direction. Here, we examine the use of the commercially available tris(pentafluorophenyl)borane with various triphenylamine derivatives to create supramolecular B–N charge transfer systems. Our results highlight the importance of a proper balance between the donor/acceptor strength and the driving force for supramolecular polymerization to achieve stable, long-range ordered B–N systems. Detailed analyses using electron paramagnetic resonance and optical spectroscopy suggest that tris(pentafluorophenyl)borane displays complex behavior with the amide-based triphenylamine supramolecular polymers and may interact in dimers or larger chiral aggregates, depending on the specific structure of the triphenylamines.

scholarly journals Living supramolecular polymerization of fluorinated cyclohexanes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Oleksandr Shyshov ◽  
Shyamkumar Vadakket Haridas ◽  
Luca Pesce ◽  
Haoyuan Qi ◽  
Andrea Gardin ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Self Assembly ◽  
Materials Science ◽  
Helical Structure ◽  
The Self ◽  
Supramolecular Polymers ◽  
Aliphatic Compound ◽  
Double Helical Structure ◽  
Key Driver ◽  
Supramolecular Polymerization

AbstractThe development of powerful methods for living covalent polymerization has been a key driver of progress in organic materials science. While there have been remarkable reports on living supramolecular polymerization recently, the scope of monomers is still narrow and a simple solution to the problem is elusive. Here we report a minimalistic molecular platform for living supramolecular polymerization that is based on the unique structure of all-cis 1,2,3,4,5,6-hexafluorocyclohexane, the most polar aliphatic compound reported to date. We use this large dipole moment (6.2 Debye) not only to thermodynamically drive the self-assembly of supramolecular polymers, but also to generate kinetically trapped monomeric states. Upon addition of well-defined seeds, we observed that the dormant monomers engage in a kinetically controlled supramolecular polymerization. The obtained nanofibers have an unusual double helical structure and their length can be controlled by the ratio between seeds and monomers. The successful preparation of supramolecular block copolymers demonstrates the versatility of the approach.

scholarly journals Triplet electron transfer and spin polarization in a palladium porphyrin–fullerene conjugate

2018 ◽  
Vol 20 (44) ◽  
pp. 28223-28231 ◽  
Author(s):  
Prashanth K. Poddutoori ◽  
Yuri E. Kandrashkin ◽  
Christopher O. Obondi ◽  
Francis D'Souza ◽  
Art van der Est
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Electron Transfer ◽  
Spin Polarization ◽  
Paramagnetic Resonance ◽  
Donor Acceptor ◽  
Electron Paramagnetic

Transient electron paramagnetic resonance (TREPR) spectroscopy is used to investigate the pathway and dynamics of electron transfer in a palladium porphyrin–fullerene donor–acceptor conjugate.

Electron Paramagnetic Resonance Studies of Donor-Acceptor Salts in Polymer Media

1989 ◽  
Vol 173 ◽  
Author(s):  
Yang-Cheng Fann ◽  
Susan Ann Jansen
Keyword(s):  
Electrical Conductivity ◽  
Electron Paramagnetic Resonance ◽  
Magnetic Properties ◽  
Charge Transfer ◽  
Molecular Electronics ◽  
Charge Transfer Complexes ◽  
Paramagnetic Resonance ◽  
Donor Acceptor ◽  
Electron Paramagnetic ◽  
Polymeric Medium

ABSTRACTCharge transfer complexes, their inherent electrical conductivity, magnetic properties and donor-acceptor redox relationships have been a focus of much research in the last several years. One direction has been in the design of memory devices and applications in molecular electronics.1,2 Our work has focused on analysis of such processes in a polymeric medium. Polycarbonate films of 7,7’,8,8’-Tetracyanoquinodimethane (TCNQ) and o-tolidine (o-T) complexes were studied by EPR spectroscopy from 100-300K. EPR spectra and magnetic susceptibility of the dispersed charge-transfer complexes are presented and compared with the pristine materials. These studies were carried out as a function of donor/acceptor stoichiometry and concentration within the polymer matrix. Saturation studies show significant differences as the composition varies. In addition the g-tensor and linewidth are strongly dependent on temperature and composition.

Metal-Free Generation of Phosphorus-Centered Radicals for the Synthesis of Phosphorus-Based Heterocycles: A Personal Account

Synthesis ◽  
2017 ◽  
Vol 49 (15) ◽  
pp. 3444-3452 ◽  
Author(s):  
Valentin Quint ◽  
Ludovik Noël-Duchesneau ◽  
Elodie Lagadic ◽  
Fabrice Morlet-Savary ◽  
Jacques Lalevée ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Short Review ◽  
Photoredox Catalysis ◽  
Mechanistic Studies ◽  
Personal Account ◽  
Paramagnetic Resonance ◽  
Metal Free ◽  
Donor Acceptor ◽  
Free Generation ◽  
Electron Paramagnetic

This short review describes our recent efforts to generate phosphorus-based radicals under metal-free conditions and their use as key intermediates for the synthesis of phosphorus-based heterocycles. In this regard, the synthesis of benzo[b]phosphole oxides and 6-phosphorylated phenanthridines will be reported. While the synthesis of the former lies in the use of photoredox catalysis, the latter have been obtained through the use of an electron donor–acceptor complex from the combination of diphenyliodonium ion with triethylamine. Mechanistic aspects of both reaction types are discussed based on detailed mechanistic studies including electron paramagnetic resonance, UV–vis spectroscopic, NMR and steady-state photolysis experiments.1 Introduction2 Photoredox Catalysis for the Generation of Phosphinoyl Radicals3 Generation of Phosphinoyl Radicals through the Formation of EDA Complexes4 Conclusions

scholarly journals Identifying the "true" repeat unit of a copolymer using time-resolved electron paramagnetic resonance spectroscopy: a case study involving PNDIT2, NDI-T2 and T-NDI-T

2022 ◽  
Author(s):  
Clemens Matt ◽  
Rukiya Matsidik ◽  
Deborah L. Meyer ◽  
Mirjam Schröder ◽  
Michael Sommer ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Electronic Structure ◽  
Conjugated Polymers ◽  
Organic Electronics ◽  
Repeat Unit ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
Donor And Acceptor ◽  
The Impact ◽  
Electron Paramagnetic

Semiconducting polymers promise to revolutionise the way electronic devices can be built and deployed for a vast array of applications ranging from light-energy conversion to sensors to thermoelectric generators. Conjugated push-pull copolymers consisting of alternating donor and acceptor moieties are at the heart of these applications, due to the large tunability of their electronic structure. Hence, knowing the repeat unit and thus the chromophore of these materials is essential for a detailed understanding of the structure--function relationship of conjugated polymers used in organic electronics applications. Therefore, spectroscopic tools providing the necessary molecular resolution that allows to discriminate between different building blocks and to decide which one actually resembles the electronic structure of the polymer are of utmost importance. Time-resolved electron paramagnetic resonance (TREPR) spectroscopy is both, perfectly suited for this task and clearly superior to optical spectroscopy, particularly when supported by quantum-chemical calculations. This is due to its molecular resolution and unique capability of using light-induced triplet states to probe the electronic structure as well as the impact of the local environment. Here, we demonstrate the power of this approach for the polymer PNDIT2 (poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)}) revealing NDI-T2 unambiguously as the "true" repeat unit of the polymer, representing the chromophore. The alternative building block T-NDI-T has a markedly different electronic structure. These results are of high importance for the rational design of conjugated polymers for organic electronics applications.

Frustrated Lewis pairs with thermally activated delayed fluorescence properties: activation of formaldehyde

2020 ◽  
Vol 49 (38) ◽  
pp. 13198-13201
Author(s):  
Young Hoon Lee ◽  
Eun Bi Nam ◽  
Junseong Lee ◽  
Sang Uck Lee ◽  
Min Hyung Lee
Keyword(s):  
Delayed Fluorescence ◽  
Fluorescence Properties ◽  
Frustrated Lewis Pairs ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Donor Acceptor ◽  
Lewis Pairs

Activation of formaldehyde (FA) by frustrated Lewis pairs (FLPs) consisting of bulky phosphines with a donor–acceptor unit and B(C6F5)3 led to the formation of FLP–FA adducts that exhibit a thermally activated delayed fluorescence.

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