C–ON bond homolysis in alkoxyamines. Part 12: the effect of the para-substituent in the 1-phenylethyl fragment

2016 ◽  
Vol 14 (14) ◽  
pp. 3574-3583 ◽  
Author(s):  
Gérard Audran ◽  
Paul Brémond ◽  
Jean-Patrick Joly ◽  
Sylvain R. A. Marque ◽  
Toshihide Yamasaki
Keyword(s):  
Bond Homolysis ◽  
Nitroxide Mediated Polymerization

The application of alkoxyamines as initiators/controllers in nitroxide mediated polymerization and as agents for theranostics requires the development of switchable (from stable one to labile one) alkoxyamines.

Versatile approach to activation of alkoxyamine homolysis by 1,3-dipolar cycloaddition for efficient and safe nitroxide mediated polymerization

2019 ◽  
Vol 55 (2) ◽  
pp. 190-193 ◽  
Author(s):  
Mariya Edeleva ◽  
Denis Morozov ◽  
Dmitriy Parkhomenko ◽  
Yulia Polienko ◽  
Anna Iurchenkova ◽  
...  
Keyword(s):  
Dipolar Cycloaddition ◽  
Bond Homolysis ◽  
Nitroxide Mediated Polymerization

In situ activation of alkoxyamine towards C–ON bond homolysis by 1,3-dipolar cycloaddition with monomers is reported.

scholarly journals Smart Control of Nitroxide-Mediated Polymerization Initiators’ Reactivity by pH, Complexation with Metals, and Chemical Transformations

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 688 ◽  
Author(s):  
Mariya Edeleva ◽  
Gerard Audran ◽  
Sylvain Marque ◽  
Elena Bagryanskaya
Keyword(s):  
Functional Groups ◽  
Chemical Transformation ◽  
Constant Temperature ◽  
Thermal Regulation ◽  
Chemical Transformations ◽  
Smart Control ◽  
Bond Homolysis ◽  
And Control ◽  
Nitroxide Mediated Polymerization ◽  
Polymerization Method

Because alkoxyamines are employed in a number of important applications, such as nitroxide-mediated polymerization, radical chemistry, redox chemistry, and catalysis, research into their reactivity is especially important. Typically, the rate of alkoxyamine homolysis is strongly dependent on temperature. Nonetheless, thermal regulation of such reactions is not always optimal. This review describes various ways to reversibly change the rate of C–ON bond homolysis of alkoxyamines at constant temperature. The major methods influencing C–ON bond homolysis without alteration of temperature are protonation of functional groups in an alkoxyamine, formation of metal–alkoxyamine complexes, and chemical transformation of alkoxyamines. Depending on the structure of an alkoxyamine, these approaches can have a significant effect on the homolysis rate constant, by a factor of up to 30, and can shorten the half-lifetime from days to seconds. These methods open new prospects for the application of alkoxyamines in biology and increase the safety of (and control over) the nitroxide-mediated polymerization method.

pH-Sensitive C–ON Bond Homolysis of Alkoxyamines of Imidazoline Series with Multiple Ionizable Groups As an Approach for Control of Nitroxide Mediated Polymerization

2011 ◽  
Vol 76 (14) ◽  
pp. 5558-5573 ◽  
Author(s):  
Mariya V. Edeleva ◽  
Igor A. Kirilyuk ◽  
Irina F. Zhurko ◽  
Dmitry A. Parkhomenko ◽  
Yuri P. Tsentalovich ◽  
...  
Keyword(s):  
Ph Sensitive ◽  
Bond Homolysis ◽  
Nitroxide Mediated Polymerization ◽  
Ionizable Groups

Grafting pH‐Responsive Copolymers to Cold Water‐Soluble Starch Using Nitroxide‐Mediated Polymerization

2021 ◽  
pp. 2100011
Author(s):  
Alexander T. Fritz ◽  
Jaime C. Cazotti ◽  
Omar Garcia‐Valdez ◽  
Niels M. B. Smeets ◽  
Marc A. Dubé ◽  
...  
Keyword(s):  
Cold Water ◽  
Soluble Starch ◽  
Water Soluble ◽  
Ph Responsive ◽  
Nitroxide Mediated Polymerization

scholarly journals Synthesis of poly (n-butyl acrylate) with tempo by nitroxide mediated polymerization method

2021 ◽  
pp. 096739112110245
Author(s):  
Amrita Sharma ◽  
PP Pande
Keyword(s):  
Butyl Acrylate ◽  
Low Cost ◽  
Polymerization Process ◽  
Polymerization Reaction ◽  
High Concentration ◽  
Acrylate Monomer ◽  
Controlled Polymerization ◽  
Acrylate Monomers ◽  
Nitroxide Mediated Polymerization ◽  
Polymerization Method

It has been observed that acrylate monomers are very difficult to polymerize with the low cost nitroxide catalyst 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO). Therefore, costly acyclic nitroxides such as N-tert-butyl-N-(1-diethylphosphono-2,2-dimethyl)-N-oxyl, (SG1), 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) and TIPNO derivatives have to be used for the polymerization of the acrylic acid derivatives. There are very few reports on the use of TEMPO-derivatives toward the polymerization of n-butyl acrylate. Generally different reducing agents viz. glucose, ascorbic acid, hydroxyacetone etc. have been used to destroy excess TEMPO during the polymerization reaction. The acrylate polymerizations fail in the presence of TEMPO due to the strong C–O bond formed between the acrylate chain end and nitroxide. To the best of our knowledge, no literature report is available on the use of TEMPO without reducing agent or high temperature initiators, toward the polymerization of n-butyl acrylate. The present study has been carried out with a view to re-examine the application of low cost nitroxide TEMPO, so that it can be utilized towards the polymerization of acrylate monomers (e.g. n-butyl acrylate). We have been able to polymerize n-butyl acrylate using the nitroxide TEMPO as initiator (via a macroinitiator). In this synthesis, a polystyrene macroinitiator was synthesized in the first step from TEMPO, after this TEMPO end-capped styrene macroinitiator (PSt-TEMPO) is used to polymerize n-butyl acrylate monomer. The amount of macroinitiator taken was varied from 0.05% to 50% by weight of n-butyl acrylate monomer. The polymerization was carried out at 120°C by bulk polymerization method. The experimental findings showed a gradual increase in molecular weight of the polymer formed and decrease in the polydispersity index (PDI) with increase in amount of PSt-TEMPO macroinitiator taken. In all experiments conversion was more than 80%. These results indicate that the polymerization takes place through controlled polymerization process. Effect of different solvents on polymerization has also been investigated. In the following experiments TEMPO capped styrene has been used as macroinitiator leading to the successful synthesis of poly n-Butyl acrylate. It has been found that styrene macroinitiator is highly efficient for the nitroxide mediated polymerization, even in very small concentration for the synthesis of poly n-butyl acrylate. High concentration of macroinitiator results in the formation of block copolymers of polystyrene and poly ( n-butyl acrylate) viz. polystyrene-block-poly-( n-butyl acrylate). The use of TEMPO toward controlled polymerization is of much importance, because it is the nitroxide commercially available at the lowest cost.

scholarly journals Computational design of pH-switchable control agents for nitroxide mediated polymerization

2017 ◽  
Vol 19 (34) ◽  
pp. 22678-22683 ◽  
Author(s):  
Ganna Gryn’ova ◽  
Leesa M. Smith ◽  
Michelle L. Coote
Keyword(s):  
Quantum Chemistry ◽  
Room Temperature ◽  
Computational Design ◽  
Acid Base ◽  
Nitroxide Mediated Polymerization

In the present work we use accurate quantum chemistry to evaluate several known and novel nitroxides bearing acid–base groups as pH-switchable control agents for room temperature NMP.

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