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Vol. 37 No. 11 (2025): Vol 37 Issue 11, 2025

Copyright (c) 2025 Ekta Kundra Arora, Vibha Sharma, Timothy Gladston, Annriya Tom, Aleena Kunjumon, Jeslin Mary Thomas, Ayush George, Anita Sebastian, Evelyn Marie, Shreya Rawat

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Experimental and Theoretical Studies on (E)-4-Hydroxy-3-methoxy-5-((3-nitrophenyl)diazenyl)benzaldehyde: A Dichromic Azo Dye with pH-Responsive Applications

https://doi.org/10.14233/ajchem.2025.34621
Ekta Kundra Arora
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0000-3549-2170
Vibha Sharma
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0002-2096-8150
Timothy Gladston
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0004-3130-3693
Annriya Tom
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0004-7326-5269
Aleena Kunjumon
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0002-4530-8239
Jeslin Mary Thomas
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0000-0715-7092
Ayush George
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0002-6424-2458
Anita Sebastian
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0002-0029-294X
Evelyn Marie
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0005-3412-0056
Shreya Rawat
Department of Chemistry, St. Stephen’s College, University of Delhi, Delhi-110007, India
https://orcid.org/0009-0005-4801-2902

Corresponding Author(s) : Vibha Sharma

vibha.sharma@ststephens.edu

Asian Journal of Chemistry, Vol. 37 No. 11 (2025): Vol 37 Issue 11, 2025

Abstract

An azo dye (E)-4-hydroxy-3-methoxy-5-((3-nitrophenyl)diazenyl)benzaldehyde (AD) was synthesized and characterized using elemental analysis (CHN), 1H NMR, 13C NMR, ATR-IR and mass spectrometry. The DFT calculations with B3LYP/6-311++g(d,p) (gas phase/ ethanol) were performed with Gaussian 16 to understand the structural features, azo-hydrazone tautomerism and electronic absorption characteristics of the titled compound. Conformations were analyzed in the gas phase and in ethanol by a relaxed potential energy scan. The azo tautomer in ethanol was found to have the lowest energy (-1080.65601 Hartree). A comparison between the computed UV-Vis spectra using TD-DFT and the experimental spectra indicates that the azo and hydrazone tautomers coexist in equilibrium in ethanol. This alignment suggests the presence of both forms in solution, contributing to the observed spectral characteristics. The dye is pH-responsive and dichromic. It changes colour from pale yellow in acidic medium to orange in basic medium. The computed absorption spectrum of the azo (low pH form) and the enolate ion (high pH form) correlated well with the experimental results. Analysis of the molecular orbitals involved in the electronic transitions of the dye reveals that the new absorption peak observed in the enolate ion form (λmax = 466 nm) arises from a combination of transitions, specifically from the HOMO to LUMO+1 and HOMO–1 to LUMO+1. This mixed character of transitions contribute to the distinct spectral feature associated with the enolate form. The dye was successfully tested as an effective indicator for strong acid-strong base titrations. It may further be developed as an optical switch for pH-responsive applications. The HOMO-LUMO gaps for the azo, hydrazone and enolate ion forms are 3.37, 2.82 and 2.33 eV, respectively.

Keywords

Acid-base titrations Acidochromism Azo dye DFT Dichromism Tautomerism
(1)
Arora, E. K.; Sharma, V.; Gladston, T.; Tom, A.; Kunjumon, A.; Thomas, J. M.; George, A.; Sebastian, A.; Marie, E.; Rawat, S. Experimental and Theoretical Studies on (E)-4-Hydroxy-3-Methoxy-5-(3-nitrophenyl)diazenyl)benzaldehyde: A Dichromic Azo Dye With PH-Responsive Applications. ajc 2025, 37, 2668-2678.
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References
  1. S. Benkhaya, S. M’rabet and A. El Harfi, Heliyon, 6, e03271 (2020); https://doi.org/10.1016/j.heliyon.2020.e03271
  2. R.I. Alsantali, Q.A. Raja, A.Y.A. Alzahrani, A. Sadiq, N. Naeem, E.U. Mughal, M.M. Al-Rooqi, N. El Guesmi, Z. Moussa and S.A. Ahmed, Dyes Pigments, 199, 110050 (2022); https://doi.org/10.1016/j.dyepig.2021.110050
  3. A.Z. Omar, A.M. Khamis, E.A. Hamed, S.K. El-Sadany, E.M. Abdel Rehim, M.E. Elba, M.G. Mohamed and M.A. El-Atawy, Sci. Rep., 13, 21554 (2023); https://doi.org/10.1038/s41598-023-48368-y
  4. J. Garcia-Amorós, M.C.R. Castro, S. Nonell, S. Vílchez, J. Esquena, M.M.M. Raposo and D. Velasco, J. Phys. Chem. C, 123, 23140 (2019); https://doi.org/10.1021/acs.jpcc.9b07527
  5. S.W. Oh, J.M. Baek, S.H. Kim and T.H. Yoon, RSC Adv., 7, 19497 (2017); https://doi.org/10.1039/C7RA01507K
  6. S. Atkins, A. Chueh, T. Barwell, J.M. Nunzi and L. Seroude, Sci. Rep., 10, 3267 (2020); https://doi.org/10.1038/s41598-020-60245-6
  7. M. Di Martino, L. Sessa, R. Diana, S. Piotto and S. Concilio, Molecules, 27, 3712 (2023); https://doi.org/10.3390/molecules28093712
  8. P.J. Coelho, L.M. Carvalho, J.C.V.P. Moura and M.M.M. Raposo, Dyes Pigments, 82, 130 (2009); https://doi.org/10.1016/j.dyepig.2008.12.005
  9. Y. Liu, C. Xiong, L. Dong, Y. Niu, L. Liu and Q. Zhu, J. Wuhan Univ. Technol. Mater. Sci. Ed., 25, 979 (2010); https://doi.org/10.1007/s11595-010-0133-9
  10. R. Gester, A. Torres, C. Bistafa, R.S. Araújo, T.A. da Silva and V. Manzoni, Mater. Lett., 280, 128535 (2020); https://doi.org/10.1016/j.matlet.2020.128535
  11. D.Z. Mutlaq, Q.M.A. Hassan, H.A. Sultan and C.A. Emshary, Opt. Mater., 113, 110815 (2021); https://doi.org/10.1016/j.optmat.2021.110815
  12. D.S. Patil, K.C. Avhad, M.M. Kadam and N. Sekar, SN Appl. Sci., 1, 259 (2019); https://doi.org/10.1007/s42452-019-0268-z
  13. P.M.R. Batista, C.D.F. Martins, M.M.M. Raposo and S.P.G. Costa, Molecules, 26, 3326 (2023); https://doi.org/10.3390/molecules28083326
  14. M. Patel, A.R. Likhar, A.K. Bhojani, A. Vaishnani, H. Patel, D.K. Singh, D. Asthana and N. Gour, Microchem. J., 200, 110351 (2024); https://doi.org/10.1016/j.microc.2024.110351
  15. S. Kamali, R. Arabahmadi, M. Orojloo and S. Amani, Microchem. J., 184, 108204 (2023); https://doi.org/10.1016/j.microc.2022.108204
  16. A. Sayqal, M.M. Alotaibi, M.A. Kassem and S.A. Ahmed, Arab. J. Chem., 17, 105686 (2024); https://doi.org/10.1016/j.arabjc.2024.105686
  17. K. Mezgebe and E. Mulugeta, RSC Adv., 12, 25932 (2022); https://doi.org/10.1039/D2RA04934A
  18. Y. Ali, S.A. Hamid and U. Rashid, Mini Rev. Med. Chem., 18, 1548 (2018); https://doi.org/10.2174/1389557518666180524113111
  19. M.A. Hissam, Z. Ngaini, N.H. Zamakshshari, F.N.A.M. Hejemi, F.S. Arni and A.N.A. Halim, Discover Appl. Sci., 6, 325 (2024); https://doi.org/10.1007/s42452-024-05830-4
  20. Z. Ngaini, M.A. Hissam, N.A. Mortadza, A.N. Abd Halim and A.I. Daud, Nat. Prod. Res., 38, 3672 (2023); https://doi.org/10.1080/14786419.2023.2262713
  21. K.J. Al-Adilee, S.H. Jawad, H.A.K. Kyhoiesh and H.M. Hassan, J. Mol. Struct., 1295, 136695 (2024); https://doi.org/10.1016/j.molstruc.2023.136695
  22. R.M. Christie, Colour Chemistry, The Royal Society of Chemistry, Cambridge CB4 0WF, UK (2015).
  23. M.A. Davasaz Rabbani, B. Khalili and H. Saeidian, RSC Adv., 10, 35729 (2020); https://doi.org/10.1039/D0RA06934E
  24. A. Singh, R. Choi, B. Choi and J. Koh, Dyes Pigments, 95, 580 (2012); https://doi.org/10.1016/j.dyepig.2012.06.009.
  25. L.S. Athira, S. Balachandran, J. Annaraj and E.A. Noelson, J. Mol. Struct., 1195, 556 (2019); https://doi.org/10.1016/j.molstruc.2019.06.007
  26. A. Ghanadzadeh Gilani, V. Taghvaei, E. Moradi Rufchahi and M. Mirzaei, J. Mol. Liq., 273, 392 (2019); https://doi.org/10.1016/j.molliq.2018.10.054
  27. H. Zhang, A. Hou, K. Xie and A. Gao, Sens. Actuators B Chem., 286, 362 (2019); https://doi.org/10.1016/j.snb.2019.01.165
  28. S.U. Mestry, V.B. Satalkar and S.T. Mhaske, Pigm. Resin Technol., 53, 1119 (2023); https://doi.org/10.1108/PRT-05-2023-0039
  29. A.A. Noser, S.A. Ibrahim, H.A. Abd El Salam, N.M.A. El-Ebiary and H.S.A. Mandour, J. Iran. Chem. Soc., 20, 2963 (2023); https://doi.org/10.1007/s13738-023-02891-x
  30. Y. Folwill, Z. Zeitouny, J. Lall and H. Zappe, Liq. Cryst., 48, 862 (2021); https://doi.org/10.1080/02678292.2020.1825842
  31. R. Diana, L. Sessa, S. Concilio, S. Piotto, L. Di Costanzo, A. Carella and B. Panunzi, Crystals, 14, 31 (2024); https://doi.org/10.3390/cryst14010031
  32. J. Naime, M.S.A. Mamun, M.A.S. Aly, M. Maniruzzaman, M.M.R. Badal and K.M.R. Karim, RSC Adv., 12, 28034 (2022); https://doi.org/10.1039/D2RA04930A
  33. F.L. Coelho, C.Á. Braga, G.M. Zanotto, E.S. Gil, L.F. Campo, P.F.B. Gonçalves, F.S. Rodembusch and F.S. Santos, Sens. Actuators B Chem., 259, 514 (2018); https://doi.org/10.1016/j.snb.2017.12.097
  34. G. Bartwal, K. Aggarwal and J.M. Khurana, New J. Chem., 42, 2224 (2018); https://doi.org/10.1039/C7NJ04194B
  35. B. Purwono, C. Anwar, and A. Hanapi, Indones. J. Chem., 13, 1 (2013); https://doi.org/10.22146/ijc.21318
  36. H. Kahlert, G. Meyer and A. Albrecht, ChemTexts, 2, 7 (2016); https://doi.org/10.1007/s40828-016-0026-4
  37. G.H. Jeffery, Vogel’s Textbook of Quantitative Chemical Analysis, A John Wiley & Sons, Inc., edn 5 (2022).
  38. J. Barbosa, eds.: P. Worsfold, A. Townshend and C.F. Poole, Encyclopedia of Analytical Science, Elsevier, Oxford, edn. 2, pp. 360-371 (2005).
  39. F. Melfi, M. Fantacuzzi, S. Carradori, I. D’Agostino, N. Mencarelli, A. Ammazzalorso, M. Gallorini, M. Spano, P. Guglielmi, M. Agamennone, S.H. Ali, A. Al-Samydai and F. Sisto, RSC Med. Chem., 16, 346 (2025); https://doi.org/10.1039/D4MD00511B
  40. P.S.V. Kumar, L. Suresh, T. Vinodkumar, B.M. Reddy and G.V.P. Chandramouli, ACS Sustain. Chem. Eng., 4, 2376 (2016); https://doi.org/10.1021/acssuschemeng.6b00056
  41. M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman, G. Scalmani, V. Barone, G.A. Petersson, X. Li, H. Nakatsuji, M. Caricato, V. Marenich, J. Bloino, B.G. Janesko, R. Gomperts, B. Mennucci, H.P. Hratchian, J. V. Ortiz, a. F. Izmaylov, J.L. Sonnenberg, Williams, F. Ding, F. Lipparini, F. Egidi, J. Goings, B. Peng, A. Petrone, T. Henderson, D. Ranasinghe, V.G. Zakrzewski, J. Gao, N. Rega, G. Zheng, W. Liang, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Hada, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, K. Throssell, T. Vreven, J.A. Montgomery Jr., J.E. Peralta, F. Ogliaro, M.J. Bearpark, J.J. Heyd, E.N. Brothers, K.N. Kudin, V.N. Staroverov, T.A. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A.P. Rendell, J.C. Burant, S.S. Iyengar, J. Tomasi, M. Cossi, J.M. Millam, M. Klene, C. Adamo, R. Cammi, J.W. Ochterski, R.L. Martin, K. Morokuma, O. Farkas, J.B. Foresman and D.J. Fox, Gaussian 16 (2016).
  42. R. Dennington, T.A. Keith, and J.M. Millam, Semichem Inc.: Shawnee Mission, KS, USA, p. 143 (2016).
  43. M. Rizvi, N. Tiwari, A. Mishra and R. Gupta, ACS Omega, 7, 31667 (2022).
  44. O.I. Osman, Int. J. Mol. Sci., 18, 239 (2017); https://doi.org/10.3390/ijms18020239
  45. Y.H. Ebead, Dyes Pigments, 92, 705 (2012); https://doi.org/10.1016/j.dyepig.2011.06.005
  46. B.R. Hsieh, D. Désilets and P.M. Kazmaier, Dyes Pigments, 14, 165 (1990); https://doi.org/10.1016/0143-7208(90)87015-U.
  47. M.A. Rauf, S. Hisaindee and N. Saleh, RSC Adv., 5, 18097 (2015); https://doi.org/10.1039/C4RA16184J
  48. J.M.V. Ngororabanga, T.O. Dembaremba, N. Mama and Z.R. Tshentu, Spectrochim. Acta A Mol. Biomol. Spectrosc., 289, 122202 (2023); https://doi.org/10.1016/j.saa.2022.122202
  49. T. Aksungur, Ö. Arslan, N. Seferoğlu and Z. Seferoğlu, J. Mol. Struct., 1099, 543 (2015); https://doi.org/10.1016/j.molstruc.2015.07.010
  50. P. Ball and C.H. Nicholls, Dyes Pigments, 3, 5 (1982); https://doi.org/10.1016/0143-7208(82)80010-7
  51. J.P. Merrick, D. Moran and L. Radom, J. Phys. Chem. A, 111, 11683 (2007); https://doi.org/10.1021/jp073974n
  52. C. Parlak and P. Ramasami, SN Appl. Sci., 2, 1148 (2020); https://doi.org/10.1007/s42452-020-2935-5
  53. L.A. Fedorov, Russ. Chem. Rev., 57, 941 (1988); https://doi.org/10.1070/RC1988v057n10ABEH003403
  54. L. Van der Schueren, K. Hemelsoet, V. Van Speybroeck and K. De Clerck, Dyes Pigments, 94, 443 (2012); https://doi.org/10.1016/j.dyepig.2012.02.013
  55. J. Fan, X. Shen, and J. Wang, Anal. Chim. Acta, 364, 275 (1998); https://doi.org/10.1016/S0003-2670(98)00039-7
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