A computational study on enzymatically driven oxidative coupling of chlorophenols: An indirect dehalogenation reaction

Szatkowski, Lukasz; Dybała-Defratyka, Agnieszka

doi:10.1016/j.chemosphere.2012.11.022

Cited by 19 publications

(6 citation statements)

References 53 publications

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“…aurescens TC1 which resembles acid-catalyzed hydrolysis rather than alkaline hydrolysis 9 . Hence, the picture emerges that different hydrolytic pathways give rise to experimental AKIE Cl values much lower than the Streitwieser Limit of 1.02 [41][42][43] isotope effects observed in this study. For the moment, since chlorine isotope effects were analysis alone would not be enough to differentiate the different reaction mechanisms.…”

contrasting

confidence: 57%

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Compound-specific chlorine isotope fractionation in biodegradation of atrazine

Lihl

Heckel

Grzybkowska

et al. 2020

Environ. Sci.: Processes Impacts

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contrasting

confidence: 57%

“…Streitwieser Limit associated with the cleavage of a C-Cl bond (KIE Cl = 1.02) [41][42][43] and to the predictions of computational calculations (Table 2). For microbial hydrolysis of atrazine an experimental AKIE Arthro Cl value of 1.0014 ± 0.0006 was calculated (see Table 1).…”

mentioning

confidence: 98%

Compound-specific chlorine isotope fractionation in biodegradation of atrazine

Lihl

Heckel

Grzybkowska

et al. 2020

Environ. Sci.: Processes Impacts

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“…The literature reveals that ligninolytic enzymes can perform different processes such as oxidation, demethylation, reduction of benzoquinones, hydroxylation, and reductive dehalogenation of chlorinated aromatic compounds 50 . Moreover, the number and position of chlorine atoms (ortho-, meta-, and para-) can limit the biotransformation capacity and reaction rate 51 .…”

Section: Resultsmentioning

confidence: 99%

Detoxification of pulping black liquor with Pleurotus ostreatus or recombinant Pichia pastoris followed by CuO/TiO2/visible photocatalysis

Rivera-Hoyos

Morales-Álvarez

Abelló-Esparza

et al. 2018

Sci Rep

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Cellulose-pulping requires chemicals such as Cl2, ClO2, H2O2, and O2. The black liquor (BL) generated exhibits a high chemical oxygen demand (COD), five-day biochemical oxygen demand (BOD5), and chlorophenol content, along with an augmented colour and increased pH. BL is often discharged into water bodies, where it has a negative impact on the environment. Towards that end, laccases are of great interest for bioremediation, since they can degrade aromatic and non-aromatic compounds while reducing O2 to water instead of H2O2. As such, we evaluated Pleurotus ostreatus and Pichia pastoris (which produces rPOXA 1B laccase) in the treatment of synthetic BL (SBL) in an “in vitro” modified Kraft process followed by CuO/TiO2/visible light photocatalysis. Treating SBL with P. ostreatus viable biomass (VB) followed by CuO/TiO2/visible light photocatalysis resulted in 80.3% COD removal and 70.6% decolourisation. Toxic compounds such as 2-methylphenol, 4-methylphenol, and 2-methoxyphenol were eliminated. Post-treated SBL exhibited low phytotoxicity, as evidenced by a Lactuca sativa L seed germination index (GI) > 50%. Likewise, SBL treatment with P. pastoris followed by VB/CuO/TiO2/visible light photocatalysis resulted in 63.7% COD removal and 46% decolourisation. Moreover, this treatment resulted in the elimination of most unwanted compounds, with the exception of 4-chlorophenol. The Lactuca sativa L seed GI of the post-treated SBL was 40%, indicating moderate phytotoxicity.

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“…62 Moreover, Szatkowski and Dybala-Defratyka predicted theoretical values of Cl-KIE's for intramolecular chlorine transfer inside chlorinated phenoxybenzenes to be in the range from 1.014 to 1.028. 63 However in this process chlorine anions were not released. In case of our model we should expect Cl-KIE values to match typical values for S N 2 reactions, and indeed, theoretical values of Cl-KIE for the predominant LS pathway in our models were in the range: 1.0084-1.0097, 1.0092-1.0102 and 1.0093-1.0097 for B3LYP, M06-L and ωB97X-D functionals, respectively.…”

Section: Chlorine Kinetic Isotope Effects (Cl-kies)mentioning

confidence: 93%

Dehalogenation of chloroalkanes by nickel(i) porphyrin derivatives, a computational study

Szatkowski

Hall

2016

Dalton Trans.

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The nickel(i) octaethylisobacteriochlorin anion ([OEiBCh-Ni]) is commonly used as a synthetic model of cofactor F from Methyl-Coenzyme M Reductase. In this regard, experimental studies show that [OEiBCh-Ni] can catalyze dehalogenation of aliphatic halides in DMF solution by a highly efficient S2 reaction. To better understand this process, we constructed theoretical models of the dehalogenation of chloromethane by a simple nickel(i) isobacteriochlorin anion and compared its reactivity with that of similar Ni complexes with other porphyrin-derived ligands: porphyrin, chlorin, bactreriochlorin, hexahydroporphyrin and octahydroporphyrin. Our calculations predict that all of the porphyrin derivative's model reactions proceed through low-spin complexes. Relative to the energy of the separate reactants the theoretical activation energies (free-energy barriers with solvation corrections) for the dehalogenation of chloromethane are similar for all of the porphyrin derivatives and range for the different functionals from 10-15 kcal mol for B3LYP to 5-10 kcal mol for M06-L and to 13-18 kcal mol for ωB97X-D. The relative free energies of the products of the dehalogenation step, L-Ni-Me adducts, have a range from -5 to -40 kcal mol for all functionals; generally becoming more negative with increasing saturation of the porphyrin ligand. Moreover, no significant differences in the theoretical chlorine kinetic isotope effect were discernable with change of porphyrin ligand.

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A computational study on enzymatically driven oxidative coupling of chlorophenols: An indirect dehalogenation reaction

Cited by 19 publications

References 53 publications

Compound-specific chlorine isotope fractionation in biodegradation of atrazine

Compound-specific chlorine isotope fractionation in biodegradation of atrazine

Detoxification of pulping black liquor with Pleurotus ostreatus or recombinant Pichia pastoris followed by CuO/TiO2/visible photocatalysis

Dehalogenation of chloroalkanes by nickel(i) porphyrin derivatives, a computational study

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