Abstract:A new method for the enzymatic synthesis of oligoaniline soluble in organic solutions is developed. Aniline oligomers showed a high inhibition of copper corrosion in aqueous HCl and NaCl solutions.
“…Kinetic studies of PANI synthesis catalyzed by soybean peroxidase (SBP) in water or water/organic solvent mixtures indicated that the enzymatic polymerization of aniline does not have an induction period or autoacceleration, which is characteristic for the simple chemical polymerization of aniline (Cruz-Silva et al 2005). Similarly, Shumakovich et al (2014) pointed out that the growth of PANI chain during the chemical oxidative polymerization of aniline occurs via the formation of oligomeric/polymeric pernigraniline intermediates which are later reduced by unreacted aniline molecules to the PANI emeraldine salt in the final polymerization phase. In contrast, oligoaniline and PANI chains in the emeraldine oxidation state are immediately formed in the laccase-catalyzed polymerization of aniline (Junker et al 2014a), i.e., the enzymatic polymerization of aniline proceeds without an induction period (initial accumulation of oligomeric pernigraniline intermediates).Fig.…”
Section: Enzymatic Oligomerization and Polymerization Mechanismsmentioning
The literature concerning the oxidative oligomerization and polymerization of various arylamines, e.g., aniline, substituted anilines, aminonaphthalene and its derivatives, catalyzed by oxidoreductases, such as laccases and peroxidases, in aqueous, organic, and mixed aqueous organic monophasic or biphasic media, is reviewed. An overview of template-free as well as template-assisted enzymatic syntheses of oligomers and polymers of arylamines is given. Special attention is paid to mechanistic aspects of these biocatalytic processes. Because of the nontoxicity of oxidoreductases and their high catalytic efficiency, as well as high selectivity of enzymatic oligomerizations/polymerizations under mild conditions—using mainly water as a solvent and often resulting in minimal byproduct formation—enzymatic oligomerizations and polymerizations of arylamines are environmentally friendly and significantly contribute to a “green” chemistry of conducting and redox-active oligomers and polymers. Current and potential future applications of enzymatic polymerization processes and enzymatically synthesized oligo/polyarylamines are discussed.
“…Kinetic studies of PANI synthesis catalyzed by soybean peroxidase (SBP) in water or water/organic solvent mixtures indicated that the enzymatic polymerization of aniline does not have an induction period or autoacceleration, which is characteristic for the simple chemical polymerization of aniline (Cruz-Silva et al 2005). Similarly, Shumakovich et al (2014) pointed out that the growth of PANI chain during the chemical oxidative polymerization of aniline occurs via the formation of oligomeric/polymeric pernigraniline intermediates which are later reduced by unreacted aniline molecules to the PANI emeraldine salt in the final polymerization phase. In contrast, oligoaniline and PANI chains in the emeraldine oxidation state are immediately formed in the laccase-catalyzed polymerization of aniline (Junker et al 2014a), i.e., the enzymatic polymerization of aniline proceeds without an induction period (initial accumulation of oligomeric pernigraniline intermediates).Fig.…”
Section: Enzymatic Oligomerization and Polymerization Mechanismsmentioning
The literature concerning the oxidative oligomerization and polymerization of various arylamines, e.g., aniline, substituted anilines, aminonaphthalene and its derivatives, catalyzed by oxidoreductases, such as laccases and peroxidases, in aqueous, organic, and mixed aqueous organic monophasic or biphasic media, is reviewed. An overview of template-free as well as template-assisted enzymatic syntheses of oligomers and polymers of arylamines is given. Special attention is paid to mechanistic aspects of these biocatalytic processes. Because of the nontoxicity of oxidoreductases and their high catalytic efficiency, as well as high selectivity of enzymatic oligomerizations/polymerizations under mild conditions—using mainly water as a solvent and often resulting in minimal byproduct formation—enzymatic oligomerizations and polymerizations of arylamines are environmentally friendly and significantly contribute to a “green” chemistry of conducting and redox-active oligomers and polymers. Current and potential future applications of enzymatic polymerization processes and enzymatically synthesized oligo/polyarylamines are discussed.
“…The MALDI spectrum is very crowded and each oligomer showed the presence of different peak clusters corresponding to its various redox states and different end groups . As an example, a mass increment of about 15 Da corresponding to polymeric species with loss of ‐NH 2 , may be the result of fragmentation of the sample in the desorption/ionization process, as reported elsewhere .…”
Section: Resultsmentioning
confidence: 53%
“…The MALDI spectrum is very crowded and each oligomer showed the presence of different peak clusters corresponding to its various redox states and different end groups [41]. As an example, a mass increment of about 15 Da corresponding to polymeric species with loss of -NH 2 , may be the result of fragmentation of the sample in the desorption/ionization process, as reported elsewhere [42][43][44][45]. As for pDANI, the spectra showed the presence of polymeric species in the range from 700 to 1600 Da, with peaks belonging to two families with different abundance (Supporting Information Figure 1B).…”
The green synthesis of highly conductive polyaniline by using two biological macromolecules, i.e laccase as biocatalyst, and DNA as template/dopant, was achieved in this work. Trametes versicolor laccase B (TvB) was found effective in oxidizing both aniline and its less toxic/mutagenic dimer N‐phenyl‐p‐phenylenediamine (DANI) to conductive polyaniline. Reaction conditions for synthesis of conductive polyanilines were set‐up, and structural and electrochemical properties of the two polymers were extensively investigated. When the less toxic aniline dimer was used as substrate, the polymerization reaction was faster and gave less‐branched polymer. DNA was proven to work as hard template for both enzymatically synthesized polymers, conferring them a semi‐ordered morphology. Moreover, DNA also acts as dopant leading to polymers with extraordinary conductive properties (∼6 S/cm). It can be envisaged that polymer properties are magnified by the concomitant action of DNA as template and dopant. Herein, the developed combination of laccase and DNA represents a breakthrough in the green synthesis of conductive materials.
“…Compared to peroxidases, the peroxide free action of laccases represents a significant advantage. However, the random character of radical reactions typically resulted in complex mixtures of oligomers and polymers . Another expected disadvantage was the possible requirement of a mediator for achieving reasonable yields .…”
Section: Enzyme Catalyzed Routes To Divanillinmentioning
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