Towards understanding monomer coordination in atom transfer radical polymerization: synthesis of [CuI(PMDETA)(π-M)][BPh4] (M = methyl acrylate, styrene, 1-octene, and methyl methacrylate) and structural studies by FT-IR and 1H NMR spectroscopy and X-ray crystallography

Braunecker, Wade A.; Pintauer, Tomislav; Tsarevsky, Nicolay V.; Kickelbick, Guido; Matyjaszewski, Krzysztof

doi:10.1016/j.jorganchem.2004.10.035

Cited by 65 publications

(62 citation statements)

References 68 publications

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“…. 17 It should be remembered that these are crystal structures and do not necessarily correspond to the solution structure when solvents or other ligands may enter the coordination sphere.…”

Section: Introductionmentioning

confidence: 99%

Solvent dependent anion dissociation limits copper(i) catalysed atom transfer reactions

Zerk

Bernhardt

2013

Dalton Trans.

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Atom transfer radical addition (ATRA) and polymerization (ATRP) reactions are commonly catalyzed by copper(I) complexes which react, reversibly, with a dormant alkyl halide initiator (RX) releasing a reactive organic radical R·. The copper catalyst bears a multidentate N-donor ligand (L) and the active catalyst is simply Cu I L. The role of the catalyst in these reactions is to abstract a halogen atom from RX forming the corresponding higher oxidation state species Cu II LX. However, in order to perform its catalytic function (in multiple turnovers) the halido ligand must be released from the copper ion en route to regenerating the active catalyst Cu I L. In this work we investigate the kinetics of the Cu I LX/Cu I L equilibrium where L is the tridentate N, N,Nʹ,N",N"-pentamethyldiethylenetriamine (PMDETA). Using electrochemical analysis we discovered that the rate of formation of the active catalyst Cu I L is strongly dependent on solvent. We demonstrate that both the kinetics and thermodynamics of this simple ligand exchange reaction are critical in the overall reaction pathway.2

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Section: Introductionmentioning

confidence: 99%

Solvent dependent anion dissociation limits copper(i) catalysed atom transfer reactions

Zerk

Bernhardt

2013

Dalton Trans.

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“…These systems are more challenging, since the more polar acrylates coordinate more strongly to Cu [42,43] than does styrene, which could potentially affect the catalyst performance. Table 1 presents the experimental conditions and properties of poly(n-butyl acrylate) (PnBA) prepared by ARGET ATRP.…”

mentioning

confidence: 99%

Activators Regenerated by Electron Transfer for Atom‐Transfer Radical Polymerization of (Meth)acrylates and Related Block Copolymers

2006

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Atom-transfer radical polymerization (ATRP) is a controlled or living radical polymerization (CRP) technique [1,2] that enables the preparation of new nanostructured materials that are not accessible by conventional free-radical polymerization (FRP). Reported herein is the ATRP of polar monomers such as (meth)acrylates and related block copolymers by means of a new initiating/catalytic method based on activators regenerated by electron transfer (ARGET) with ppm (10 À4 mol % vs. monomer) amounts of Cu catalyst.[3]ATRP [4][5][6][7] provides a simple route to many well-defined (co)polymers with precisely controlled functionalities, topologies, and compositions. [8][9][10] It has been very successfully applied to the preparation of many nanocomposites, hybrids, and bioconjugates. [11][12][13][14][15][16][17][18][19][20][21][22][23] The advantages of ATRP, in comparison with other CRP processes, include the large range of available monomers and (macro)initiators, the simplicity of reaction setup, and the ability to conduct the process over a large range of temperatures, solvents, and dispersed media. [6,7,24] ATRP (Scheme 1) is a repetitive atom-transfer process between a macromolecular alkyl halide P n ÀX and a redoxactive transition-metal complex Cu I ÀX/ligand in which P n C radicals propagate (rate constant of propagation k p ) and are reversibly formed (rate constants k a and k da ). The growing radicals also terminate by coupling or disproportionation (rate constant k t ).An inherent feature, but also a limitation of ATRP, is the presence of a catalyst (a transition-metal complex with Scheme 1. Mechanism for ATRP.

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“…At 298 K, the resonance of the NH proton is too broad to be observed; however, a pronounced narrowing together with a stepwise downfield shift is observed upon lowering the temperature to 183 K. In the same temperature interval, no substantial changes in the spectral line shape or chemical shift values were observed, and the maximum chemical shift difference between 183 and 298 K was 0.5 ppm for the 13 C nuclei and 0.1 ppm for the vinyl 1 H nuclei. Thus, we conclude that the different kinds of Cu-bonded allyl moieties observed in the crystal structure must exchange in solution at a rate sufficiently high to give rise, at least in the 1 H and 13 C NMR spectra, to a unique averaged set of signals.…”

Section: Nmr Spectroscopic Analysismentioning

confidence: 92%

“…This decrease may be due to the decrease in the double bond character of the allyl moiety as a consequence of the bond with Cu, and it is in agreement with both the bond length obtained by X-ray single crystal determination and with the values reported in literature for Cu I complexes with vinyl monomers such as methacrylates, styrene and 1-octene. [13] …”

Section: Ftir Spectroscopic Analysismentioning

confidence: 99%

“…The "metal 4 ] n (Cu2) was observed. The new compound was characterised by X-ray single crystal diffraction and FTIR, 1 H and 13 C NMR spectroscopic analysis. In an attempt to investigate the redox mechanism and the equilibria leading to the formation of the observed unusual Cu I polymeric complex, gas chromatography coupled with mass spectrometry (GC-MS) experiments were carried out, which allowed us to identify 3,4-dimethylpyrrole as the oxidation product of the reaction, leading to the reduction of Cu II to Cu I .…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and Characterisation of a New Cu(O₂CNAllyl₂)₂ Carbamato Complex and an Unusual Polymeric Cu^I Complex [Cu^I₄Cl₄(NHAllyl₂)₄]_n: New Insights into Metal Carbamato Chemistry

et al. 2009

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Transition‐metal N,N‐dialkylcarbamato complexes represent an interesting class of compounds that can be conveniently used as precursors for the controlled formation of inorganic compounds, typically oxides. They can also be used as convenient precursors for chemical grafting of metal oxides on oxide surfaces as well as for the synthesis of inorganic–organic hybrid materials. In this last case, the presence of double bonds on the complex would enable its covalent embedding into a polymer matrix through reaction with suitable monomers. To this aim, we addressed the synthesis of an allyl‐functionalised copper carbamato complex. During the synthesis of the N,N‐diallylcarbamato complex Cu(O2CNAllyl2)2 (Cu1), the formation of the crystalline and unusual polymeric CuI complex [CuI4Cl4(NHAllyl2)4]n (Cu2) was observed. The new compound was characterised by X‐ray single crystal diffraction and FTIR, 1H and 13C NMR spectroscopic analysis. In an attempt to investigate the redox mechanism and the equilibria leading to the formation of the observed unusual CuI polymeric complex, gas chromatography coupled with mass spectrometry (GC–MS) experiments were carried out, which allowed us to identify 3,4‐dimethylpyrrole as the oxidation product of the reaction, leading to the reduction of CuII to CuI.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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Towards understanding monomer coordination in atom transfer radical polymerization: synthesis of [CuI(PMDETA)(π-M)][BPh4] (M = methyl acrylate, styrene, 1-octene, and methyl methacrylate) and structural studies by FT-IR and 1H NMR spectroscopy and X-ray crystallography

Cited by 65 publications

References 68 publications

Solvent dependent anion dissociation limits copper(i) catalysed atom transfer reactions

Solvent dependent anion dissociation limits copper(i) catalysed atom transfer reactions

Activators Regenerated by Electron Transfer for Atom‐Transfer Radical Polymerization of (Meth)acrylates and Related Block Copolymers

Synthesis and Characterisation of a New Cu(O₂CNAllyl₂)₂ Carbamato Complex and an Unusual Polymeric Cu^I Complex [Cu^I₄Cl₄(NHAllyl₂)₄]_n: New Insights into Metal Carbamato Chemistry

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Towards understanding monomer coordination in atom transfer radical polymerization: synthesis of [CuI(PMDETA)(π-M)][BPh4] (M = methyl acrylate, styrene, 1-octene, and methyl methacrylate) and structural studies by FT-IR and 1H NMR spectroscopy and X-ray crystallography

Cited by 65 publications

References 68 publications

Solvent dependent anion dissociation limits copper(i) catalysed atom transfer reactions

Solvent dependent anion dissociation limits copper(i) catalysed atom transfer reactions

Activators Regenerated by Electron Transfer for Atom‐Transfer Radical Polymerization of (Meth)acrylates and Related Block Copolymers

Synthesis and Characterisation of a New Cu(O2CNAllyl2)2 Carbamato Complex and an Unusual Polymeric CuI Complex [CuI4Cl4(NHAllyl2)4]n: New Insights into Metal Carbamato Chemistry

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Synthesis and Characterisation of a New Cu(O₂CNAllyl₂)₂ Carbamato Complex and an Unusual Polymeric Cu^I Complex [Cu^I₄Cl₄(NHAllyl₂)₄]_n: New Insights into Metal Carbamato Chemistry