Solvent, substituents and pH effects towards the spectral shifts of some highly colored indicators

Mamdouh S. Masoud, Rehab M.I. Elsamra, Sokaina S. Hemdan


: The solvatochromic responses of six indicators namely Sudan orange, Alizarin yellow R, Aurin tricarboxylic acid, Alizarin yellow GG, Titan yellow and Eriochrome black-T dissolved in seven solvents of different polarities have been measured at room temperature. The UV/Vis absorption spectral shifts were analyzed by multiple linear regression analysis and Kamlet-Taft's equation. The observed solvatochromism was found to depend on the presence of donor and acceptor substituents in the conjugated systems of the indicator and the physical properties of the solvent molecules. The pH effects on the wavenumbers of the absorption band maxima of some indicators with different constituents were discussed at room temperature and the mechanism of ionization was explained. The dissociation constants (pKa) of the investigated compounds were precisely assessed and the existence of individual predominant ionic species was assigned by constructing distribution diagrams at different pH ranges.


azo dyes; solvatochromism; Kamlet-Taft parameters; acid dissociation constant

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R. W. Sabnis, Hand book of acid-base indicators, Squire, Sanders & Dempsey LLP, San Francisco, USA, 2007

M. S. Zakerhamidi, M. Keshavarz, H. Tajalli, A. Ghanadzadeh, S. Ahmadi, M. Moghadam, S. H. Hosseini, V. Hooshangi, J. Mol. Liq. 154 (2010) 94

G. S. Uscumlic, J. B. Nikolic, J. Serb. Chem. Soc. 74 (2009) 1335

Y. D. Daldal, E. C. Demiralay, S. A. Ozkan, J. Braz. Chem. Soc. 27 (2016) 493

M. S. Masoud, A. M. Hindawy, M. A. Mostafa, A. M. Ramadan, Spectrosc. Lett. 30 (1997) 1227

M. S. Masoud, E. A. Khalil, A. M. Ramadan, Y. M. Gohar, A. H. Sweyllam, Spectrochim. Acta 67A (2007) 669

M. S. Masoud, E. A. Khalil, A. M. Ramadan, S. A. Mokhtar, O. F. Hafez, Syn. React. Inorg. Metal-Org. Nano-Metal Chem. 44 (2014) 402

M. S. Masoud, A. M. Hafez, M. Sh. Ramadan, A. E. Ali, J. Serb. Chem. Soc. 67 (2002) 833

M. S. Masoud, A. M. Hindawy, A. A. Soayed, M. Y. Abd El-Kaway, Fluid Phase Equilib. 312 (2011) 37

M. S. Masoud, E. A. Khalil, S. Abou El Enein, H. M. Kamel, Eur. J. Chem. 2 (2011) 420

M. S. Masoud, A. M. Ramadan, A. A. Soayed, S. M. S. Ammar, J. Iran. Chem. Soc. 13 (2016) 931

F. W. Fowler, A. R. Katritzky, R. J. D. Rutherford, J. Chem. Soc. B (1971) 460

C. Reichardt, Chem. Rev. 94 (1994) 2319

J. G. Kirkwood, J. Chem. Phys. 2 (1934) 351

J. G. David, H. E. Hallam, Spectrochim. Acta 23A (1967) 593

M. J. Kamlet, J. -L. M. Abboud, M. H. Abraham, R. W. Taft, J. Org. Chem. 48 (1983) 2877

L. J. Hilliard, D. S. Foulk, H. S. Gold, C. E. Rechsteiner, Anal. Chim. Acta 133 (1981) 319

R. W. Taft, J. -L. M. Abboud, M. J. Kamlet, J. Org. Chem.49 (1984) 2001

M. Dakiky, K. Kanan, K. Khamis, Dyes Pigm. 41 (1999) 199

İ. Sıdır, E. Taşal, Y. Gülseven, T. Gungor, H. Berber, C. Oğretir, Int. J. Hydrogen Energy 34 (2009) 5267

N. M. Rageh, Spectrochim. Acta 60A (2004) 103

A. R. Monahan, A. F. De Luca, A. T. Ward, J. Org. Chem. 36 (1971) 3838

N. Valentic, D. Mijin, G. Uscumlic, A. Marinkovic, S. Petrovic, Arkivoc 12 (2006) 81

R. M. Issa, H. Sadek, I. I. Ezzat, Z. Phys. Chem. 74 (1971) 17

A. A. Muk, M. B. Pravica, Anal. Chim. Acta 45 (1969) 534

J. C. Colleter, Ann. Chim. (Paris), 5 (1960) 415

D. V. Jahagirdar, D. D. Khanolkar, J. lnorg. Nucl. Chem. 35 (I973) 921

P. W. Alexander, R. J. Sleet, Aust. J. Chem. 23 (1970) 1183

E. Bosch, J. Guiteras, A. Izquierdo, M. D. Prat, Anal. Lett. 21 (1988) 1273.



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