Supplementary data from: Are natural-based isothiocyanate derivatives alternative antioxidant additives used in petrochemical products?
Data files
Jan 20, 2025 version files 22.98 MB
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ESI_TCNgo.docx
22.98 MB
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README.md
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Abstract
Synthetic additives used in petrochemical products, such as plastics, rubbers, resins, and polymers, can enter the environment as contaminants and pollute the aquatic and soil environment. Thus, using natural-based alternative compounds has excellent potential to reduce the negative impact. In this study, the role of natural-based isothiocyanate derivatives Cp1-Cp4, i.e., allylisothiocyanate, 1-isothiocyanate-3-methylbutane, 4-methylphenyl isothiocyanate, and 2-phenylethyl isothiocyanate in use as primary antioxidant additives was studied via their HOꞏ-radical scavenging activity. Formal hydrogen transfer, radical adduct formation, and single electron transfer mechanisms were investigated in water and pentyl ethanoate (PEA) using Density Functional Theory at M06-2X/6-311++G(3df,3pd)//M06-2X/6-311++G(d,p) level of theory. The results illustrated the high HOꞏ-scavenging activity of the isothiocyanate compounds with rate constants of about 108 - 109 M-1s-1. Allylisothiocyanate Cp1 represents the most efficient HOꞏ-scavenger with koverallof5.20 × 109 M-1s-1 in water and 1.85 × 109 M-1s-1 in PEA. These results allow us to enrich the data on effective antioxidant additives from natural sources to reduce HOꞏ-radicals-induced oxidation processes in different environmental conditions.
README: Supplementary data from: Are natural-based isothiocyanate derivatives alternative antioxidant additives used in petrochemical products?
Description of the data and file structure
The electronic supplementary information (ESI) within our submission contains underlying data that was generated and used to support the conclusions presented in our study. This data is compatible with the CC0 waiver required by Dryad for publication and is not included in our related manuscript.
The ESI file presents a detailed explanation of the computational method used in the main manuscript.
The ESI data show additional results for formal hydrogen transfer (FHT) (Table S1 to S3) and radical adduct formation (RAF) (Table S4 to S6) reactions between the studied isothiocyanates and HO• radicals.
File: ESI_TCNgo.docx
List of Tables in the ESI file
Table S1 shows relative reaction enthalpies at 0 K (∆r*H*0K) for reactant complex (RC), transition states (TS), product complexes (PC), and product (P) of FHT reactions between the studied isothiocyanates and HO• radical in water and pentyl ethanoate (PEA) using the M06-2X/6-311++G(3df,3pd)//M06-2X/6-311++G(d,p) level of theory. All energies are in kcal mol-1.
Table S2 displays optimized structures, and Cartesian coordinates of all reactant complexes (RC), transition states (TS), product complexes (PC), and products (P) for FHT reactions between the studied isothiocyanates and HO• in water and pentyl ethanoate (PEA) at the M06-2X/6-311++G(d,p) level of theory.
Table S3 shows thermal rate constant (*k*T, M-1s-1) and diffusion rate constant (*k*D, M-1s-1) calculated at 298 K for FHT reactions at each C−H between the studied isothiocyanates and HO• radical in water and pentyl ethanoate (PEA) using the M06-2X/6-311++G(3df,3pd)//M06-2X/6-311++G(d,p) level of theory.
Table S4 shows relative reaction enthalpies at 0 K (∆r*H*0K) for reactant complex (RC), transition states (TS), and product (P) of RAF reactions between the studied isothiocyanates and HO• radical in water and pentyl ethanoate (PEA) using the M06-2X/6-311++G(3df,3pd)//M06-2X/6-311++G(d,p) level of theory. All energies are in kcal mol-1.
Table S5 displays Optimized structures, and Cartesian coordinates of all reactant complexes (RC), transition states (TS), and products (P) for RAF reactions between the studied isothiocyanates and HO• in water and pentyl ethanoate (PEA) at the M06-2X/6-311++G(d,p) level of theory.
Table S6 shows thermal rate constant (*k*T, M-1s-1) and diffusion rate constant (*k*D, M-1s-1) calculated at 298 K for RAF reactions between the studied isothiocyanates and HO• radical in water and pentyl ethanoate (PEA) using the M06-2X/6-311++G(3df,3pd)//M06-2X/6-311++G(d,p) level of theory.
Code/Software
All DFT calculations are performed with the Gaussian 16 Rev.C.01 package (https://gaussian.com/).
The Gaussian Post Processor (GPOP) program is employed to calculate the rate constants of the studied reactions (http://akrmys.com/gpop/).
Methods
All DFT calculations were performed by Gaussian 16 Rev. C.01 package. The Gaussian Post Processor (GPOP) program was used to calculate the rate constant for chemical reactions.