Abstract

The kinetics of azo-chalcone dye formation from (E)-1-(4-nitrophenyl)-3-phenylprop-2-en-1-one and diazotized 4-aminobenzoic acid were investigated. Chalcones exhibit valuable biological and optical properties, yet the kinetic parameters governing their azo-coupled derivatives remain incompletely characterized. This study aimed to determine the reaction rate constants, activation energy, and half-life for azo-chalcone dye formation under varying temperatures, and to validate the experimental findings using density functional theory ( DFT ) calculations. UV-Vis spectroscopy monitored the dye formation at 346 nm over 130 min at four temperatures ( 275, 285, 295, and 305K ) under natural pH and optimized 1:10 stoichiometric ratio ( Chalcone reagent ). Pseudo-first-order kinetic analysis and the Arrhenius equation were applied. DFT calculations using the B3LYP/6-31G method were performed with Gaussian 09. The reaction followed pseudo-first-order kinetics (R² = 0.9627 – 0.9887). The rate constant increased from 0.0529 min⁻¹ at 275K to 0.0616 min⁻¹ at 305K, with corresponding half-life decreases from 13.1 to 11.3 min. Arrhenius analysis yielded an exceptional linear correlation (R² = 0.9999) and an activation energy of 3.54 kJ mol⁻¹. DFT calculations identified nitrogen and oxygen atoms as the primary donor-active sites. The temperature-dependent kinetic behavior aligns with literature on azo-imine dye formation, indicating a low energy barrier and minimal thermal sensitivity for the pseudo-first-order proces. DFT validation supports the spectroscopic observations and elucidates the electronic properties governing reactivity. The azo-chalcone dye formation follows pseudo-first-order kinetics under the optimized conditions. The rate constants increase with temperature, and DFT confirms the reaction mechanism. These findings contribute to understanding azo dye synthesis for potential biological and optical applications.

References

1. Sweeting, S.G., et al., The solubility and stability of heterocyclic chalcones compared with trans-chalcone. Structural Science, 2020. 76(1): p. 13-17.
2. v. Kostanecki, S. and J. Tambor, Ueber die sechs isomeren Monooxybenzalacetophenone (Monooxychalkone). Berichte der deutschen chemischen Gesellschaft, 1899. 32(2): p. 1921-1926.
3. Sharma, V., V. Kumar, and P. Kumar, Heterocyclic chalcone analogues as potential anticancer agents. Anticancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry-Anti-Cancer Agents), 2013. 13(3): p. 422-432.
4. Yadav, N., et al., Antimalarial activity of newly synthesized chalcone derivatives in vitro. Chemical biology & drug design, 2012. 80(2): p. 340-347.
5. Sharma, N., et al., Design, economical synthesis and antiplasmodial evaluation of vanillin derived allylated chalcones and their marked synergism with artemisinin against chloroquine resistant strains of Plasmodium falciparum. European Journal of Medicinal Chemistry, 2014. 79: p. 350-368.
6. Guantai, E.M., et al., Enone–and chalcone–chloroquinoline hybrid analogues: in silico guided design, synthesis, antiplasmodial activity, in vitro metabolism, and mechanistic studies. Journal of medicinal chemistry, 2011. 54(10): p. 3637-3649.
7. Mishra, N., et al., synthesis of novel substituted 1, 3-diaryl propenone derivatives and their antimalarial activity in vitro. European journal of medicinal chemistry, 2008. 43(7): p. 1530-1535.
8. Valla, A., et al., New syntheses and potential antimalarial activities of new ‘retinoid-like chalcones’. European journal of medicinal chemistry, 2006. 41(1): p. 142-146.
9. Rammohan, A., et al., Chalcone synthesis, properties and medicinal applications: a review. Environmental Chemistry Letters, 2020. 18(2): p. 433-458.
10. Sreevidya, T.V., B. Narayana, and H.S. Yathirajan, Synthesis and characterization of some chalcones and their cyclohexenone derivatives. Central European Journal of Chemistry, 2010. 8(1): p. 174.
11. Al Zahrani, N.A., et al., synthesis of novel chalcone-based phenothiazine derivatives as antioxidant and anticancer agents. Molecules, 2020. 25(19): p. 4566
12. Dhar, R., et al., 2′, 4-Dihydroxy-3′, 4′, 6′-trimethoxychalcone from Chromolaena odorata possesses antiinflammatory effects via inhibition of NF-κB and p38 MAPK in lipopolysaccharide-activated RAW 264.7 macrophages. Immunopharmacology and immunotoxicology, 2018. 40(1): p. 43-51.
13. Rossi, G. and J. Avellino, An evaluation of the antihistaminic activity of a new series of chalcone derivatives. American journal of pharmacy and the sciences supporting public health, 1957. 129(9): p. 324-331.
14. Gan, F.-F., et al., Novel dual-targeting anti-proliferative dihydrotriazine-chalcone derivatives display suppression of cancer cell invasion and inflammation by inhibiting the NF-κB signaling pathway. Food and chemical toxicology, 2018. 116: p. 238-248.
15. Hsieh, C.-Y., et al., Design and synthesis of benzimidazole-chalcone derivatives as potential anticancer agents. Molecules, 2019. 24(18): p. 3259.
16. Khanapure, S., et al., Anticancer activity of ruthenocenyl chalcones and their molecular docking studies. Journal of Molecular Structure, 2018. 1173: p. 142-147.
17. Saeed, N. H., Ali, R. T., & Saied, S. M. (2025). Computational study on the Estramustine (EMCYT) and its active metabolites anticancer drugs 17-α-estradiol and nornitrogen. Results in Chemistry, 102747.
18. Benouda, H., et al., synthesis of a series of chalcones and related flavones and evaluation of their antibacterial and antifungal activities. Letters in Drug Design & Discovery, 2019. 16(1): p. 93-100.
19. Monga, V., et al., synthesis and evaluation of new chalcones, derived pyrazoline and cyclohexenone derivatives as potent antimicrobial, antitubercular and antileishmanial agents. Medicinal chemistry research, 2014. 23(4): p. 2019-2032.
20. Bandgar, B.P., et al., Synthesis and biological evaluation of simple methoxylated chalcones as anticancer, antiinflammatory and antioxidant agents. Bioorganic & medicinal chemistry, 2010. 18(3): p. 1364-1370.
21. Al Ajelly, H.M.S., The Pharmaceutical Prof le of Oxazine Compound Derived from Chalcones. Am J Pharmacol Ther, 2021. 5(1): p. 006-008
22. Arbeloa, F.L., et al., Handbook of advanced electronic and photonic materials and devices. HS Nalwa (Ed.), 2001. 7.
23. Al Hammouri, S., Synthesis and Biological Evaluation of Chalcones, Isoxazole and Pyrazole Derivatives Attached with Adamantyl Substituent. 2019.
24. Ibrahim-Ouali, M. and F. Dumur, Steroidal chalcones and derivatives: A review. ARKIVOC-Online Journal of Organic Chemistry, 2022. 2021.
25. Rao, C.M., et al., synthesis, characterization and anti microbial activity of novel chalcones and its di hydro pyrimidinenones. International journal of life science and pharma research, 2015. 5(3): p. P13-P16.
26. Uwakwe, K., et al., Molecular dynamics simulations and quantum chemical calculations for the adsorption of some imidazoline derivatives on iron surface. Global Journal of Pure and Applied Sciences, 2017. 23(1): p. 69- 80.
27. Ikeuba, A.I., et al., Review of computational methods used in the evaluation corrosion inhibition of metallic materials. Discover Chemical Engineering, 2024. 4(1): p. 28.
28. Azzouz, A. and A. Obed Agha, The influence of surfactants and solvents on the stability constant value of some azo dyes formation between oximes and the diazotized Sulphanilic acid salt. Journal of Education and Science, 2005. 17(2): p. 10-16.
29. Hawaiz, F.E., D.J. Raheem, and M.K. Samad, Synthesis and Characterization of Some New Azoimine Dyes and their Applications. Synthesis and Characterization of Some New Azoimine Dyes and their Applications, 2016. 18.
30. Özkınalı, S., M.S. Çavuş, and B.U. Sakin, synthesis, characterisation and DFT calculations of azo-imine dyes. Journal of the Turkish Chemical Society Section A: Chemistry, 2018. 5(1): p. 159-178.
31. Al-Marsumi, A. and M. Al-Niemi, Determination of thermodynamic parameters and studying the stability of some aromatic complexes derived from 4-dimethyl aminobenzaldehyde with dinitro aniline reagent. EDITORIAL BOARD, 2021. 16(2-3): p. 19.
32. Ali Mohsin, A.H., H. Al-Niemi, and M. Mahmoud, Thermodynamic study for the stability of aromatic complexes formation derived from the reaction of 4-dimethyl amino benzaldehyde with diazotized dinitro aniline reagents. Egyptian Journal of Chemistry, 2022. 65(2): p. 421-437.
33. Kshash, A.H., Synthesis and Characterization of Novel Nitroaniline-Based Azo Compounds as Acid-Base Indicators. Iraqi Journal for Applied Science, 2025. 2(4): p. 18-29.
34. Mohammed Abdulrazaq Mahdy, & Noor H. M. Saeed. (2025). A comparative study of the theoretical and practical values of ionization constants for amino acid derivatives in the neutral and anionic states. Applied Chemical Engineering, 8(4), ACE-5796. https://doi.org/10.59429/ace.v8i4.5796
35. Al-Ghouti, M., et al., Thermodynamic behaviour and the effect of temperature on the removal of dyes from aqueous solution using modified diatomite: a kinetic study. Journal of Colloid and Interface Science, 2005. 287(1): p. 6-13
36. Hasb, A. M., & Saeed, N. H. (2025). Chlorination of n-benzoyl valine by sodium n-chloro-para-toluene sulfonyl amide (cat) hydrochloric acidic: a kinetic and mechanism study. Kimya Problemleri, 23(2), 239-248.
37. Bernasconi, C.F., M.L. Ragains, and S. Bhattacharya, Reactions that generate aromatic molecules: is aromatic stabilization less or more advanced than bond changes at the transition state? Kinetic and thermodynamic acidities of rhenium carbene complexes. Journal of the American Chemical Society, 2003. 125(40): p. 12328- 12336.
38. Reeves, R. and L. Tong, Kinetics of Reaction of Nucleophilic Reagents with Naphthoquinone Imine Dyes in Alkaline Solution. Journal of the American Chemical Society, 1962. 84(11): p. 2050-2057.
39. Maqbool, T., P. Srikiratiwong, and H.S. Fogler, Effect of temperature on the precipitation kinetics of asphaltenes. Energy & fuels, 2011. 25(2): p. 694-700.
40. Al-Niemi, H. and M. Mahmoud, Kinetic Study for the reactions of paracetamol with diazotized (P-nitroaniline & sulfanilic acid sodium salt) reagents. Egyptian Journal of Chemistry, 2023. 66(2): p. 535-542.
41. Mohammed, I.Y. and I.K. Jassism, Synthesis of New Heterocyclic Polymers from Chalcone. Iraqi National Journal of Chemistry, 2017. 17(1).
42. Ahmed, N. and H. Ridha, Synthesis of Some New Chalcone Compounds Derived From (Phenyl Quinoxaline Methyl Benzotriazol) of an Expected Biological Activity. Journal of Education and Science, 2019. 28(2): p. 1.0- 22.0.
43. Mwene-Mbeja, T.M., Chemical stability of pharmaceutical organic compounds. Am. J. Biomed. Sci. Res, 2019. 6: p. 14-22
44. Dong, J., et al., Determination of the half-life of 161Tb. Applied Radiation and Isotopes, 2023. 193: p. 110647.
45. Kiraci, A. and H. Yurtseven, Temperature dependence of the Raman frequency, damping constant and the activation energy of a soft-optic mode in ferroelectric barium titanate. Ferroelectrics, 2012. 432(1): p. 14-21.
46. Terracciano, A.C., et al., Effect of catalytically active Ce0. 8Gd0. 2O1. 9 coating on the heterogeneous combustion of methane within MgO stabilized ZrO2 porous ceramics. Combustion and Flame, 2017. 180: p. 32-39.
47. Jensen, F., Activation energies and the Arrhenius equation. Quality and Reliability Engineering International, 1985. 1(1): p. 13-17.
48. Balachandran, V., A. Lakshmi, and A. Janaki, Ab initio, DFT, HOMO–LUMO and Natural Bond Orbital analyses of the electronic structure of 2-mercapto-1-methylimidazole. Journal of Molecular Structure, 2011. 1006(1-3): p. 395-401.
49. Sebastian, S., et al., Study on conformational stability, molecular structure, vibrational spectra, NBO, TD-DFT, HOMO and LUMO analysis of 3, 5-dinitrosalicylic acid by DFT techniques. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2015. 136: p. 1107-1118.
50. Puzzarini, C., J.F. Stanton, and J. Gauss, Quantum-chemical calculation of spectroscopic parameters for rotational spectroscopy. International Reviews in Physical Chemistry, 2010. 29(2): p. 273-367.
51. Sweeting, S.G., et al., The solubility and stability of heterocyclic chalcones compared with trans-chalcone. Structural Science, 2020. 76(1): p. 13-17.
52. v. Kostanecki, S. and J. Tambor, Ueber die sechs isomeren Monooxybenzalacetophenone (Monooxychalkone). Berichte der deutschen chemischen Gesellschaft, 1899. 32(2): p. 1921-1926.
53. Sharma, V., V. Kumar, and P. Kumar, Heterocyclic chalcone analogues as potential anticancer agents. AntiCancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry-Anti-Cancer Agents), 2013. 13(3): p. 422-432
54. Yadav, N., et al., Antimalarial activity of newly synthesized chalcone derivatives in vitro. Chemical biology & drug design, 2012. 80(2): p. 340-347.
55. Sharma, N., et al., Design, economical synthesis and antiplasmodial evaluation of vanillin derived allylated chalcones and their marked synergism with artemisinin against chloroquine resistant strains of Plasmodium falciparum. European Journal of Medicinal Chemistry, 2014. 79: p. 350-368.
56. Guantai, E.M., et al., Enone–and chalcone–chloroquinoline hybrid analogues: in silico guided design, synthesis, antiplasmodial activity, in vitro metabolism, and mechanistic studies. Journal of medicinal chemistry, 2011. 54(10): p. 3637-3649.
57. Mishra, N., et al., Synthesis of novel substituted 1, 3-diaryl propenone derivatives and their antimalarial activity in vitro. European journal of medicinal chemistry, 2008. 43(7): p. 1530-1535
58. Valla, A., et al., New syntheses and potential antimalarial activities of new ‘retinoid-like chalcones’. European journal of medicinal chemistry, 2006. 41(1): p. 142-146.
59. Rammohan, A., et al., Chalcone synthesis, properties and medicinal applications: a review. Environmental Chemistry Letters, 2020. 18(2): p. 433-458.
60. Sreevidya, T.V., B. Narayana, and H.S. Yathirajan, Synthesis and characterization of some chalcones and their cyclohexenone derivatives. Central European Journal of Chemistry, 2010. 8(1): p. 174.
61. Rossi, G. and J. Avellino, An evaluation of the antihistaminic activity of a new series of chalcone derivatives. American journal of pharmacy and the sciences supporting public health, 1957. 129(9): p. 324-331.
62. Gan, F.-F., et al., Novel dual-targeting anti-proliferative dihydrotriazine-chalcone derivatives display suppression of cancer cell invasion and inflammation by inhibiting the NF-κB signaling pathway. Food and chemical toxicology, 2018. 116: p. 238-248.
63. Hsieh, C.-Y., et al., Design and synthesis of benzimidazole-chalcone derivatives as potential anticancer agents. Molecules, 2019. 24(18): p. 3259.
64. Khanapure, S., et al., Anticancer activity of ruthenocenyl chalcones and their molecular docking studies. Journal of Molecular Structure, 2018. 1173: p. 142-147.
65. Wan, Z., et al., Synthesis, antiviral bioactivity of novel 4-thioquinazoline derivatives containing chalcone moiety. Molecules, 2015. 20(7): p. 11861-11874.
66. Benouda, H., et al., Synthesis of a series of chalcones and related flavones and evaluation of their antibacterial and antifungal activities. Letters in Drug Design & Discovery, 2019. 16(1): p. 93-100.
67. Monga, V., et al., Synthesis and evaluation of new chalcones, derived pyrazoline and cyclohexenone derivatives as potent antimicrobial, antitubercular and antileishmanial agents. Medicinal chemistry research, 2014. 23(4): p. 2019-2032.
68. Bandgar, B.P., et al., Synthesis and biological evaluation of simple methoxylated chalcones as anticancer, anti-inflammatory and antioxidant agents. Bioorganic & medicinal chemistry, 2010. 18(3): p. 1364-1370.
69. Al Ajelly, H.M.S., The Pharmaceutical Prof le of Oxazine Compound Derived from Chalcones. Am J Pharmacol Ther, 2021. 5(1): p. 006-008.
70. Arbeloa, F.L., et al., Handbook of advanced electronic and photonic materials and devices. HS Nalwa (Ed.), 2001. 7.
71. Al Hammouri, S., Synthesis and Biological Evaluation of Chalcones, Isoxazole and Pyrazole Derivatives Attached with Adamantyl Substituent. 2019.
72. Ibrahim-Ouali, M. and F. Dumur, Steroidal chalcones and derivatives: A review. ARKIVOC-Online Journal of Organic Chemistry, 2022. 2021.
73. Rao, C.M., et al., Synthesis, characterization and anti microbial activity of novel chalcones and its di hydro pyrimidinenones. International journal of life science and pharma research, 2015. 5(3): p. P13-P16.
74. Uwakwe, K., et al., Molecular dynamics simulations and quantum chemical calculations for the adsorption of some imidazoline derivatives on iron surface. Global Journal of Pure and Applied Sciences, 2017. 23(1): p. 69-80
75. Ali Mohsin, A.H., H. Al-Niemi, and M. Mahmoud, Thermodynamic study for the stability of aromatic complexes formation derived from the reaction of 4-dimethyl amino benzaldehyde with diazotized dinitro aniline reagents. Egyptian Journal of Chemistry, 2022. 65(2): p. 421-437.
76. Meng, G., et al., Modular click chemistry libraries for functional screens using a diazotizing reagent. Nature, 2019. 574(7776): p. 86-89.
77. Mohammed, H.A., K.S. Ahmed, and S.I. Hamadamin, Kinetics and Thermodynamic Studies of the Iodination of Sultams Using A Spectroscopic Technique.
78. Balachandran, V., A. Lakshmi, and A. Janaki, Ab initio, DFT, HOMO–LUMO and Natural Bond Orbital analyses of the electronic structure of 2-mercapto-1-methylimidazole. Journal of Molecular Structure, 2011. 1006(1-3): p. 395-401.
79. Sebastian, S., et al., Study on conformational stability, molecular structure, vibrational spectra, NBO, TDDFT, HOMO and LUMO analysis of 3, 5-dinitrosalicylic acid by DFT techniques. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2015. 136: p. 1107-1118.
80. Puzzarini, C., J.F. Stanton, and J. Gauss, Quantum-chemical calculation of spectroscopic parameters for rotational spectroscopy. International Reviews in Physical Chemistry, 2010. 29(2): p. 273-367.
81. Al-Ghouti, M., et al., Thermodynamic behaviour and the effect of temperature on the removal of dyes from aqueous solution using modified diatomite: a kinetic study. Journal of Colloid and Interface Science, 2005. 287(1): p. 6-13.
82. Reeves, R. and L. Tong, Kinetics of Reaction of Nucleophilic Reagents with Naphthoquinone Imine Dyes in Alkaline Solution. Journal of the American Chemical Society, 1962. 84(11): p. 2050-2057.
83. Maqbool, T., P. Srikiratiwong, and H.S. Fogler, Effect of temperature on the precipitation kinetics of asphaltenes. Energy & fuels, 2011. 25(2): p. 694-700.
84. Al-Niemi, H. and M. Mahmoud, Kinetic Study for the reactions of paracetamol with diazotized (Pnitroaniline & sulfanilic acid sodium salt) reagents. Egyptian Journal of Chemistry, 2023. 66(2): p. 535-542.
85. Yeğiner, G., et al., Transition metal (II) complexes with a novel azo-azomethine Schiff base ligand: Synthesis, structural and spectroscopic characterization, thermal properties and biological applications. Journal of fluorescence, 2017. 27(6): p. 2239-2251.
86. Elbadawy, H.A., et al., Synthesis, characterization, computational and dyeing behavior of Cu (II) and Zn (II) metal complexes derived from azo-Schiff bases containing phenol derivatives. BMC chemistry, 2025. 19(1): p. 207.