European Journal of Chemistry

Exploring solvatochromism in Nile Blue 690 dye: Evaluating dipole moments across the ground and excited states


Main Article Content

Darukaswamy Tulahalli Hirematada
Mallikarjun Kalagouda Patil
Sanjeev Ramchandra Inamdar
Kotresh Mare Goudar


This study investigates the photophysical properties of Nile Blue 690 (NB-690) dye using spectroscopic techniques. Absorption and fluorescence spectroscopy were used to analyze NB-690, revealing pronounced bathochromic shifts in both absorption and fluorescence spectra, indicative of the π → π* transition. The study focuses on estimating ground- and excited-state dipole moments of NB-690 through solvatochromic shifts in absorption and fluorescence spectra. Various computational methods, including the Bilot-Kawski approach for ground state dipole moment computation, and the Reichardt correlation, the Bakhshiev, the Lippert-Mataga, and the Kawski-Chamma-Viallet methods for calculating the excited state dipole moment, were utilized. The results demonstrate excited-state dipole moment values of 6.922, 5.529, 5.529, 5.529, and 4.615 D, respectively, using the Lippert-Mataga, Bakhshiev, Kawski-Chamma-Viallet and solvent polarity correlation approaches. Significantly, the excited state dipole moment surpasses the ground state dipole moment, attributed to the significant π-electron density redistribution upon excitation. Intriguingly, both excited- and ground-state dipole moments align parallel to each other at a 0° angle. In general, these findings underscore the potential utility of NB-690 in optoelectronic applications, highlighting its responsiveness to environmental signals and providing valuable information for further exploration in the field.

icon graph This Abstract was viewed 94 times | icon graph Article PDF downloaded 20 times

How to Cite
Hirematada, D. T.; Patil, M. K.; Inamdar, S. R.; Goudar, K. M. Exploring Solvatochromism in Nile Blue 690 Dye: Evaluating Dipole Moments across the Ground and Excited States. Eur. J. Chem. 2024, 15, 178-185.

Article Details

Crossref - Scopus - Google - European PMC

[1]. Jose, J.; Burgess, K. Benzophenoxazine-based fluorescent dyes for labeling biomolecules. Tetrahedron 2006, 62, 11021-11037.

[2]. Ghoneim, N. Photophysics of Nile red in solution. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2000, 56, 1003-1010.

[3]. Ghanadzadeh, A.; Zeini, A.; Kashef, A. Environment effect on the electronic absorption spectra of crystal violet. J. Mol. Liq. 2007, 133, 61-67.

[4]. Ghanadzadeh Gilani, A.; Moghadam, M.; Zakerhamidi, M. S. Solvatochromism of Nile red in anisotropic media. Dyes Pigm. 2012, 92, 1052-1057.

[5]. Blanchard, G. J. Ultrafast stimulated emission spectroscopy. In Topics in Fluorescence Spectroscopy; Springer US: Boston, MA, 2002; pp. 253-303.

[6]. Kubinyi, M.; Grofcsik, A.; Pápai, I.; Jeremy Jones, W. Rotational reorientation dynamics of nile blue A and oxazine 720 in protic solvents. Chem. Phys. 2003, 286, 81-96.

[7]. Grofcsik, A.; Kubinyi, M.; Ruzsinszky, A.; Veszprémi, T.; Jones, W. J. Quantum chemical studies on excited state intermolecular proton transfer of oxazine dyes. J. Mol. Struct. 2000, 555, 15-19.

[8]. Simon, J. D.; Thompson, P. A. Spectroscopy and rotational dynamics of oxazine 725 in alcohols: A test of dielectric friction theories. J. Chem. Phys. 1990, 92, 2891-2896.

[9]. Blanchard, G. J. A study of the state-dependent reorientation dynamics of oxazine 725 in primary normal aliphatic alcohols. J. Phys. Chem. 1988, 92, 6303-6307.

[10]. Sackett, D. L.; Wolff, J. Nile red as a polarity-sensitive fluorescent probe of hydrophobic protein surfaces. Anal. Biochem. 1987, 167, 228-234.

[11]. Fleming, S.; Mills, A.; Tuttle, T. Predicting the UV-vis spectra of oxazine dyes. Beilstein J. Org. Chem. 2011, 7, 432-441.

[12]. Sackett, D. L.; Knutson, J. R.; Wolff, J. Hydrophobic surfaces of tubulin probed by time-resolved and steady-state fluorescence of nile red. J. Biol. Chem. 1990, 265, 14899-14906.

[13]. Hejazi, M. S.; Raoof, J.-B.; Ojani, R.; Golabi, S. M.; Asl, E. H. Brilliant cresyl blue as electroactive indicator in electrochemical DNA oligonucleotide sensors. Bioelectrochemistry 2010, 78, 141-146.

[14]. Ensafi, A. A.; Amini, M. A highly selective optical sensor for catalytic determination of ultra-trace amounts of nitrite in water and foods based on brilliant cresyl blue as a sensing reagent. Sens. Actuators B Chem. 2010, 147, 61-66.

[15]. Peng, J.-J.; Liu, S.-P.; Wang, L.; He, Y.-Q. Studying the interaction between CdTe quantum dots and Nile blue by absorption, fluorescence and resonance Rayleigh scattering spectra. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2010, 75, 1571-1576.

[16]. Jose, J.; Ueno, Y.; Burgess, K. Water‐soluble Nile Blue derivatives: Syntheses and photophysical properties. Chem. Eur. J. 2009, 15, 418-423.

[17]. Zheng, H.; Chen, X.-L.; Zhu, C.-Q.; Li, D.-H.; Chen, Q.-Y.; Xu, J.-G. Brilliant cresyl blue as a new red region fluorescent probe for determination of nucleic acids. Microchem. J. 2000, 64, 263-269.

[18]. Gilani, A. G.; Moghadam, M.; Zakerhamidi, M. S. Dimeric spectra analysis in Microsoft Excel: A comparative study. Comput. Methods Programs Biomed. 2011, 104, 175-181.

[19]. Mannekutla, J. R.; Mulimani, B. G.; Inamdar, S. R. Solvent effect on absorption and fluorescence spectra of coumarin laser dyes: Evaluation of ground and excited state dipole moments. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2008, 69, 419-426.

[20]. Thipperudrappa, J.; Biradar, D. S.; Manohara, S. R.; Hanagodimath, S. M.; Inamadar, S. R.; Manekutla, R. J. Solvent effects on the absorption and fluorescence spectra of some laser dyes: Estimation of ground and excited-state dipole moments. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2008, 69, 991-997.

[21]. Rautela, R.; Joshi, N. K.; Joshi, H. C.; Tewari, N.; Pant, S. Solvatochromic study of 2-hydroxy-4-methylquinoline for the determination of dipole moments and solute-solvent interactions. J. Mol. Liq. 2010, 154, 47-51.

[22]. Tewari, N.; Joshi, N. K.; Rautela, R.; Gahlaut, R.; Joshi, H. C.; Pant, S. On the ground and excited state dipole moments of dansylamide from solvatochromic shifts of absorption and fluorescence spectra. J. Mol. Liq. 2011, 160, 150-153.

[23]. Kanya, R.; Ohshima, Y. Determination of dipole moment change on the electronic excitation of isolated Coumarin 153 by pendular-state spectroscopy. Chem. Phys. Lett. 2003, 370, 211-217.

[24]. Kawski, A. On the estimation of excited-state dipole moments from solvatochromic shifts of absorption and fluorescence spectra. Z. Naturforsch. A 2002, 57, 255-262.

[25]. Homocianu, M.; Airinei, A.; Dorohoi, D. O.; Olariu, I.; Fifere, N. Solvatochromic effects in the UV/vis absorption spectra of some pyridazinium ylides. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2011, 82, 355-359.

[26]. Kawski, A.; Kukliński, B.; Bojarski, P. Excited state dipole moments of 4-(dimethylamino)benzaldehyde. Chem. Phys. Lett. 2007, 448, 208-212.

[27]. Raikar, U. S.; Renuka, C. G.; Nadaf, Y. F.; Mulimani, B. G.; Karguppikar, A. M.; Soudagar, M. K. Solvent effects on the absorption and fluorescence spectra of coumarins 6 and 7 molecules: Determination of ground and excited state dipole moment. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2006, 65, 673-677.

[28]. Biradar, D. S.; Siddlingeshwar, B.; Hanagodimath, S. M. Estimation of ground and excited state dipole moments of some laser dyes. J. Mol. Struct. 2008, 875, 108-112.

[29]. Reichardt, C. Solvatochromic dyes as solvent polarity indicators. Chem. Rev. 1994, 94, 2319-2358.

[30]. Ghanadzadeh Gilani, A.; Hosseini, S. E.; Moghadam, M.; Alizadeh, E. Excited state electric dipole moment of nile blue and brilliant cresyl blue: A comparative study. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2012, 89, 231-237.

[31]. Martinez, V.; Henary, M. Nile red and Nile blue: Applications and syntheses of structural analogues. Chemistry 2016, 22, 13764-13782.

[32]. Arslan, H.; Mansuroglu, D. S.; VanDerveer, D.; Binzet, G. The molecular structure and vibrational spectra of N-(2,2-diphenylacetyl)-N′-(naphthalen-1yl)-thiourea by Hartree-Fock and density functional methods. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2009, 72, 561-571.

[33]. Lombardi, J. R. Correlation between structure and dipole moments in the excited states of substituted benzenes. J. Am. Chem. Soc. 1970, 92, 1831-1833.

[34]. Lee, S. H.; Suh, J. K.; Li, M. Determination of bovine serum albumin by its enhancement effect of Nile blue fluorescence. Bull. Korean Chem. Soc. 2003, 24, 45-48.

[35]. Das, K.; Jain, B.; Patel, H. S. Nile Blue in Triton-X 100/benzene-hexane reverse micelles: a fluorescence spectroscopic study. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2004, 60, 2059-2064.

[36]. Krihak, M.; Murtagh, M. T.; Shahriari, M. R. Spectroscopic Study of the Effects of Various Solvents and Sol-Gel Hosts on the Chemical and Photochemical Properties of Thionin and Nile Blue A. J. Solgel Sci. Technol. 1997, 10, 153-163.

[37]. Maliwal, B. P.; Kuśba, J.; Lakowicz, J. R. Fluorescence energy transfer in one dimension: Frequency‐domain fluorescence study of DNA-fluorophore complexes. Biopolymers 1995, 35, 245-255.

[38]. Lakowicz, J. R.; Piszczek, G.; Kang, J. S. On the possibility of long-wavelength long-lifetime high-quantum-yield luminophores. Anal. Biochem. 2001, 288, 62-75.

[39]. Nikas, D. C.; Foley, J. W.; Black, P. M. Fluorescent imaging in a glioma model in vivo. Lasers Surg. Med .2001, 29, 11-17.

[40]. Lin, C. E.; Shulok, J. R.; Wong, Y. K.; Schanbacher, C. F.; Cincotta, L.; Foley, J. W. Photosensitization, Uptake, and Retention of Phenoxazine Nile Blue Derivatives in Human Bladder Carcinoma Cells. Cancer Res 1991, 51 (4), 1109-1116 article/51/4/1109/497497/Photosensitization-Uptake-and-Retention-of.

[41]. Lin, C.-W.; Shulok, J. R. Enhancement of nile blue derivative‐induced photocytotoxicity by nigericin and low cytoplasmic pH.Photochem. Photobiol. 1994, 60, 143-146.

[42]. Pihlasalo, S.; Engbert, A.; Martikkala, E.; Ylander, P.; Hänninen, P.; Härmä, H. Nonspecific particle-based method with two-photon excitation detection for sensitive protein quantification and cell counting. Anal. Chem. 2013, 85, 2689-2696.

[43]. Nadaf, Y. F.; Mulimani, B. G.; Gopal, M.; Inamdar, S. R. Ground and excited state dipole moments of some exalite UV laser dyes from solvatochromic method using solvent polarity parameters. Theochem. 2004, 678, 177-181.

[44]. Bilot, L.; Kawski, A. ZurTheorie des Einflusses von Lösungsmitteln auf die Elektronenspektren der Moleküle. Z. Naturforsch. A 1962, 17, 621-627.

[45]. Rabek, J. F. Progress in Photochemistry and Photophysics, Volume V; CRC Press: Boca Raton, FL, 1992.

[46]. Lippert, E. Dipolmoment und Elektronenstruktur von angeregten Molekülen. Z. Naturforsch. A 1955, 10, 541-545.

[47]. Mataga, N.; Kaifu, Y.; Koizumi, M. Solvent effects upon fluorescence spectra and the dipole moments of excited molecules. Bull. Chem. Soc. Jpn. 1956, 29, 465-470.

[48]. Bakhshiev, N. G. Universal molecular interactions and their effect on the position of the electronic spectra of molecules in two-component solutions. Opt. Spectrosc. 1961, 10, 379-384.

[49]. Rauf, M. A.; Graham, J. P.; Bukallah, S. B.; Al-Saedi, M. A. S. Solvatochromic behavior on the absorption and fluorescence spectra of Rose Bengal dye in various solvents. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2009, 72, 133-137.

[50]. Lee, J.-M.; Ruckes, S.; Prausnitz, J. M. Solvent polarities and Kamlet−Taft parameters for ionic liquids containing a pyridinium cation. J. Phys. Chem. B 2008, 112, 1473-1476.

[51]. Edward, J. T. Molecular volumes and the Stokes-Einstein equation. J. Chem. Educ. 1970, 47, 261.

[52]. Najare, M. S.; Patil, M. K.; Mantur, S.; Nadaf, A. A.; Inamdar, S. R.; Khazi, I. A. M. Highly conjugated D-π-A-π-D form of novel benzo[b]thiophene substituted 1,3,4‑oxadiazole derivatives; Thermal, optical properties, solvatochromism and DFT studies. J. Mol. Liq. 2018, 272, 507-519.

[53]. Kostjukov, V.; Leontieva, S.; Savchenko, E.; Rybakova, K.; Voronin, D. Photoexcitation of Nile blue dye in aqueous solution: Td-dft study. Russian Journal of Biological Physics and Chemistry 2022, 7, 209-221.

[54]. Mehata, M. S.; Singh, A. K.; Sinha, R. K. Experimental and theoretical study of hydroxyquinolines: hydroxyl group position dependent dipole moment and charge-separation in the photoexcited state leading to fluorescence. Methods Appl. Fluoresc. 2016, 4, 045004.

[55]. Suppan, P. Excited-state dipole moments from absorption/ fluorescence solvatochromic ratios. Chem. Phys. Lett. 1983, 94, 272-275.

Supporting Agencies

Karnatak University, Dharwad-580003, Karnataka, India
Most read articles by the same author(s)

Most read articles by the same author(s)


Dimensions - Altmetric - scite_ - PlumX

Downloads and views


Download data is not yet available.


Metrics Loading ...
License Terms
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

License Terms


Copyright © 2024 by Authors. This work is published and licensed by Atlanta Publishing House LLC, Atlanta, GA, USA. The full terms of this license are available at and incorporate the Creative Commons Attribution-Non Commercial (CC BY NC) (International, v4.0) License ( By accessing the work, you hereby accept the Terms. This is an open access article distributed under the terms and conditions of the CC BY NC License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited without any further permission from Atlanta Publishing House LLC (European Journal of Chemistry). No use, distribution, or reproduction is permitted which does not comply with these terms. Permissions for commercial use of this work beyond the scope of the License ( are administered by Atlanta Publishing House LLC (European Journal of Chemistry).