Durch definierte Rhodiumkomplexe vermittelte Polymerisationen

Tan, Nicholas; Lowe, Andrew B.

doi:10.1002/ange.201909909

Cited by 12 publications

(4 citation statements)

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“…Clearly, PPh 3 retarded the propagation step by coordinating to rhodium. [10][11][12][13][14][15] From these results,w er ealized that the aryl rhodium(I) species formed from boronic acid 1a did not function as an efficient initiator for the polymerization of 5a. Other boronic acids were also tested, but the results were not improved.…”

Section: Design and Development Of The Catalytic Systemmentioning

confidence: 97%

“…[8,9] However,e xamples of the controlled polymerization of substituted acetylenes are still sparse as compared to those of vinyl monomers. [10] In 1994, Noyori and coworkers reported living polymerization of phenylacetylenes using ac ombination of the rhodium(I) complex Rh(CCPh)(nbd)(PPh 3 ) 2 and N,N-dimethylaminopyridine (DMAP). [11] Following that report, they also showed that similar living polymerization was possible with ac onvenient multicomponent catalytic system composed of [Rh-(nbd)OMe] 2 /PPh 3 /DMAP or [Rh(nbd)Cl] 2 /NaOMe/PPh 3 / DMAP (Figure 1a).…”

Section: Introductionmentioning

confidence: 99%

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Facile and Versatile Synthesis of End‐Functionalized Poly(phenylacetylene)s: A Multicomponent Catalytic System for Well‐Controlled Living Polymerization of Phenylacetylenes

et al. 2020

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Ar hodium-based multicomponent catalytic system for well-controlled living polymerization of phenylacetylenes has been developed. The catalytic system is composed of readily available and bench-stable [Rh(nbd)Cl] 2 ,aryl boronic acid derivatives,d iphenylacetylene,5 0% aqueous KOH, and PPh 3 .T his system offers am ethod for the facile and versatile synthesis of various end-functionalized cis-stereoregular poly-(phenylacetylene)s because components from aryl boronic acids and diphenylacetylene were introduced to the initiating end of the polymers.T he polymerization reaction shows atypical living nature with ahigh initiation efficiency,and the molecular weight of the resulting poly(phenylacetylene)s can be readily controlled with very narrowm olecular-weight distributions (M w /M n = 1.02-1.09). The experimental results suggest that the present catalytic system has ahigher polymerization activity than the polymerization activities of other rhodium-based catalytic systems previously reported.

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Section: Design and Development Of The Catalytic Systemmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Facile and Versatile Synthesis of End‐Functionalized Poly(phenylacetylene)s: A Multicomponent Catalytic System for Well‐Controlled Living Polymerization of Phenylacetylenes

et al. 2020

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“…A suitable crystal 0.25 mm × 0.17 mm × 0.10 mm was selected and mounted on a suitable support on an XtaLAB Synergy, single source at home/near, HyPix diffractometer. The crystal was kept at a steady T = 120.01 (10) K during data collection. The structure was solved with the ShelXT structure solution program using the Intrinsic Phasing solution method and by using Olex Computational Chemistry.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

“…The transition-metal-mediated (co)polymerization of arylacetylenes, including 1-substituted and 1,2-disubstituted substrates, in a noncontrolled manner, is well documented. − In distinct contrast, there is a notable dearth of literature reports concerning the living (co)polymerization of arylacetylene monomers and related alkyne substrates such as propargyl esters/amides and arylisocyanides. − With regard to arylacetylenes, Kishimoto et al were the first to report the living polymerization of phenylacetylene (PhC 2 H) employing an in situ generated pentacoordinate rhodium-alkynyl species, Rh(nbd)(CCPh)(PPh 3 ) 2 (nbd = 2,5-norbornadiene). This complex was isolated, and the solid-state structure reported with the species adopting a slightly distorted trigonal bipyramidal geometry.…”

Section: Introductionmentioning

confidence: 99%

(η⁴-Tetrafluorobenzobarrelene)-η¹-((tri-4-fluorophenyl)phosphine)-η¹-(2-phenylphenyl)rhodium(I): A Catalyst for the Living Polymerization of Phenylacetylenes

et al. 2021

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(η4-Tetrafluorobenzobarrelene)-η1-((tri-4-fluorophenyl)phosphine)-η1-(2-phenylphenyl)rhodium(I), Rh(tfb)(biph)(PAr3), was prepared and evaluated as a catalyst in the controlled, stereospecific (co)polymerization of arylacetylenes. Following recrystallization, the complex was characterized by single-crystal X-ray diffraction, elemental analysis, and multinuclear NMR spectroscopy, including 103Rh and 31P-103Rh{1H, 103Rh} heteronuclear multiple quantum coherence (HMQC) experiments. Single-crystal X-ray diffraction indicated that Rh(tfb)(biph)(PAr3) adopts a slightly distorted square-planar geometry consistent with previously reported tetracoordinate rhodium(I)-aryl and -vinyl complexes. 103Rh and 2D 31P-103Rh{1H} HMQC NMR spectroscopy confirmed the purity and stability of the new complex in solution. In the presence of excess P(4-FC6H4)3 as a rate modifier, the Rh(I)-aryl catalyst mediated the homopolymerization of phenylacetylene, PhC2H, in a controlled manner as evidenced from the linearity of the pseudo-first-order kinetic plots, the evolution of molecular weight and dispersity, and the quantitative crossover efficiency in a self-blocking experiment. The broader utility of Rh(tfb)(biph)(PAr3) was demonstrated in the polymerization of a series of functional arylacetylenes, including 4-trifluoromethoxyphenylacetylene and 3,4-dichlorophenylacetylene, as well as in the preparation of well-defined AB diblock copolymers of phenylacetylene with the trifluoromethoxy and dichloro derivatives. Computational studies using density functional theory allowed a quantitative comparison between Rh(tfb)(biph)(PAr3) and the 2,5-norbornadiene (nbd) analogue, Rh(nbd)(biph)(PAr3). Results indicated that the former has a lower HOMO energy compared to the nbd derivative and is consistent with the enhanced π-acidity of the tetrafluorobenzobarrelene ligand species. Calculations similarly indicated that Rh(tfb)(biph)(PAr3) has a slightly higher binding affinity for PhC2H. Finally, we highlight the role the biph aryl ligand plays in stabilizing the rhodium complex through a C–H agostic and η2–π interactions and different steps in the catalyst initiation process.

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Photochemical Electrocyclization of Poly(phenylacetylene)s: Unwinding Helices to Elucidate their 3D Structure in Solution

et al. 2021

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Photochemical electrocyclization of poly(phenylacetylene)s (PPAs) is used for the structural elucidation of apolyene backbone.This method not only allows classification of PPAs in cis-cisoidal (w 1 < 908 8)o rc is-transoidal structures (w 1 > 908 8), but also approximating w 1 .APPAs olution is illuminated with visible light and monitoring the photochemical electrocyclization of the PPAhelix by measuring the ECD spectra at different times.P PAsw ith ac is-cisoidal structure show ar eduction of the ECD signal of at least 50 %b efore 30 min of irradiation, while cis-transoidal helices need much longer time because the transoidal bond must be isomerized. The different cis-cisoidal and cis-transoidal helices require different times to decrease their ECD signal by 50 %(t 1/2), depending on the degree of compression or stretching of the helix, establishing ar elationship between the secondary structure adopted by PPA(w 1)a nd the time required to lose the ECD vinylic signal by light irradiation.

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Durch definierte Rhodiumkomplexe vermittelte Polymerisationen

Cited by 12 publications

References 83 publications

Facile and Versatile Synthesis of End‐Functionalized Poly(phenylacetylene)s: A Multicomponent Catalytic System for Well‐Controlled Living Polymerization of Phenylacetylenes

Facile and Versatile Synthesis of End‐Functionalized Poly(phenylacetylene)s: A Multicomponent Catalytic System for Well‐Controlled Living Polymerization of Phenylacetylenes

(η⁴-Tetrafluorobenzobarrelene)-η¹-((tri-4-fluorophenyl)phosphine)-η¹-(2-phenylphenyl)rhodium(I): A Catalyst for the Living Polymerization of Phenylacetylenes

Photochemical Electrocyclization of Poly(phenylacetylene)s: Unwinding Helices to Elucidate their 3D Structure in Solution

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Durch definierte Rhodiumkomplexe vermittelte Polymerisationen

Cited by 12 publications

References 83 publications

Facile and Versatile Synthesis of End‐Functionalized Poly(phenylacetylene)s: A Multicomponent Catalytic System for Well‐Controlled Living Polymerization of Phenylacetylenes

Facile and Versatile Synthesis of End‐Functionalized Poly(phenylacetylene)s: A Multicomponent Catalytic System for Well‐Controlled Living Polymerization of Phenylacetylenes

(η4-Tetrafluorobenzobarrelene)-η1-((tri-4-fluorophenyl)phosphine)-η1-(2-phenylphenyl)rhodium(I): A Catalyst for the Living Polymerization of Phenylacetylenes

Photochemical Electrocyclization of Poly(phenylacetylene)s: Unwinding Helices to Elucidate their 3D Structure in Solution

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(η⁴-Tetrafluorobenzobarrelene)-η¹-((tri-4-fluorophenyl)phosphine)-η¹-(2-phenylphenyl)rhodium(I): A Catalyst for the Living Polymerization of Phenylacetylenes