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Degradation of Indigo Dye Using Quantum Mechanical Calculations


  • Halla T. Mohammed Anesthesia Techniques Department, Al-Mustaqbal University College, Iraq
  • Ahmed M. Kamil Ministry of Education, Babylon Education Directorate, Iraq.
  • Hayder M. Abduljalil Physics Department, College of Science, University of Babylon, Babylon, Iraq
  • Abbas A- Ali Drea Chemistry Department College of Science, University of Babylon, Babylon, Iraq
  • Mohammed A. Al-Seady Environmental Research and Studies Centre, University of Babylon, Babylon, Iraq.



Degradation, DFT, Indigo dye, PM3, superoxide free radical


The semiempirical (PM3) and DFT quantum mechanical methods were used to investigate the theoretical degradation of Indigo dye. The chemical reactivity of the Indigo dye was evaluated by comparing the potential energy stability of the mean bonds. Seven transition states were suggested and studied to estimate the actually starting step of the degradation reaction. The bond length and bond angle calculations indicate that the best active site in the Indigo dye molecule is at C10=C11.  The most possible transition states are examined for all suggested paths of Indigo dye degradation predicated on zero-point energy and imaginary frequency. The first starting step of the reaction mechanism is proposed. The change in enthalpy, Gibbs free energy and change in entropy of the overall reaction are equal to -548268.223 kcal/mol, 30831.951 kcal/mol and 48.552 cal/mol.deg, respectively. The activation energy is 46176.405 kcal/mol. The reaction rate is equal to .


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Kamil A, Abdalrazak F, Halbus A, Hussein F. Adsorption of bismarck brown R dye onto multiwall carbon nanotubes. J Environ Anal Chem. 2014; 1(104): 2.

Salahuddin N, Abdelwahab MA, Akelah A, Elnagar M. Adsorption of Congo red and crystal violet dyes onto cellulose extracted from Egyptian water hyacinth. Nat. Hazards. 2021; 105(2): 1375-94. DOI: 10.1007/s11069-020-04358-1

Franchi D, Calamante M, Coppola C, Mordini A, Reginato G, Sinicropi A, et al. Synthesis and characterization of new organic dyes containing the indigo core. Molecules. 2020; 25(15): 3377.

Kamil AM, Mohammed HT, Balakit AA, Hussein FH, Bahnemann DW, El-Hiti GA. Synthesis, characterization and photocatalytic activity of carbon nanotube/titanium dioxide nanocomposites. Arab J Sci Eng. 2018; 43(1): 199-210, DOI: 10.1007/s13369-017-2861-z

Cheng Z, Tan ALK, Tao Y, Shan D, Ting KE, Yin XJ. Synthesis and characterization of iron oxide nanoparticles and applications in the removal of heavy metals from industrial wastewater, Int. J Photoenergy. 2012; 2012: 1-5 , DOI: 10.1155/2012/608298

Chen X, Yang Y, Ke Y, Chen C, Xie S. A comprehensive review on biodegradation of tetracyclines: Current research progress and prospect. Sci Total Environ. 2022: 814: 1-13 . DOI: 10.1016/j.scitotenv.2021.152852

Shi X, Chen Z, Liu X, Wei W, Ni B-J. The photochemical behaviors of microplastics through the lens of reactive oxygen species: Photolysis mechanisms and enhancing photo-transformation of pollutants. Sci Total Environ. 2022: 846: 157498. DOI: 10.1016/j.scitotenv.2022.157498

Deng Y, Zhao R. Advanced oxidation processes (AOPs) in wastewater treatment. Curr Pollut Rep. 2015; 1(3): 167-76.

Kubba RM, Mohammed MA, Ahamed LS. DFT Calculations and Experimental Study to Inhibit Carbon Steel Corrosion in Saline Solution by Quinoline-2-One Derivative. Baghdad Sci J. 2021; 18: 113-123 .

Mohammed HT, Abbas A, Drea A. Simulation Study of Adrenaline Synthesis from Phenylalanine. J Adv Chem. 2017; 12: 3888-3901.

Drea A, Naman S, Jaffer B. Theoretical degradation study of methomyl. J Appl Chem. 2012; 1: 126-137 .

TM H. HyperChem TM for windows molecular modeling system. 8.0.9 ed: Hypercupe, Inc. 2011.

Parks C, Alborzi E, Akram M, Pourkashanian M. DFT Studies on Thermal and Oxidative Degradation of Monoethanolamine. Ind Eng Chem Res. 2020; 59(34): 15214-15225.‏

Kubba RM, Mohammed MA. Theoretical and Experimental Study of Corrosion Behavior of Carbon Steel Surface in 3.5 NaCl and 0.5 M HCl with Different Concentrations of Quinolin-2-One Derivative. Baghdad Sci J. 2022;19: 105-120 .

Noureddine O, Issaoui N, Al-Dossary O. DFT and molecular docking study of chloroquine derivatives as antiviral to coronavirus COVID-19. J King Saud Univ Sci. 2021; 33(1): 101248.

Wen M, Blau SM, Spotte-Smith EWC, Dwaraknath S, Persson KA. BonDNet: a graph neural network for the prediction of bond dissociation energies for charged molecules. Chem Sci J. 2021; 12(5): 1858-68.

Guthardt R, Bruhn C, Färber C, Siemeling U. Effect of the Lead (II) Bond Angle on the Reactivity of Diaminoplumbylenes toward Ammonia: From Inertness to Immediate Ammonolysis. Organometallics. 2020; 39(23): 4174-7.

Birkholz AB, Schlegel HB. Using bonding to guide transition state optimization. J Comput Chem. 2015; 36(15): 1157-66.

Chen B, Tian F, Wang M, Peng C. Electron transfer and energy barrier co-modulation: unravelling the role of sequential fluorination in high-rate CO2 photoreduction on conjugated organic polymers. Appl Catal A: Gen. 2022: 638: 118618.

Chen L, Qi X, Tang J, Xin H, Liang Z. Reaction pathways and cyclic chain model of free radicals during coal spontaneous combustion. Fuel. 2021; 293: 120436.

Guo J, Xie T, Yang S, Xie Q, Liu Q, Qin J. Free-Radical and Non-Free-Radical Based Reaction Pathways of Iodide Oxidation by Hydrogen Peroxide in Acid Solution–Ab Initio Calculations. Russ J Phys Chem A. 2021; 95(1): S15-S22.