European Journal of Chemistry

Spectroscopic study of solvent effects on the electronic absorption spectra of morpholine and its complexes


Main Article Content

Mamdouh Saad Masoud
Alaa Eldin Ali
Gehan Shaaban Elasala
Rehab Elsaid Elwardany


The electronic absorption spectra of morpholine and its five morpholine complexes have been studied in different solvents of various polarities. The regression and correlation coefficients have been calculated with the SPSS program. Solvation energy relationships were deduced from spectral shifts and correlated with solvent parameters α (solvent hydrogen bond donor acidity), β (solvent hydrogen bond acceptor basicity), and π* (dipolarity/polarizability). The percentage contributions of the calculated solvatochromic parameters show that classic solvation effects play a major role in explaining the spectral shifts in all investigated complexes. The blue shift of [Fe(MOR)3Cl3]·4H2O, [Ni(MOR)4Cl2]·4H2O, and [Cu(MOR)4Cl2]·6H2O complexes is due to the formation of hydrogen bonds, which suggests the stabilization of the ground electronic state compared with the excited state. [CuNi(MOR)2Cl4]·4H2O and [CuZn(MOR)3Cl4]·2H2O are mixed metal complexes that suffer a red shift due to the solute-solvent interactions, which causes stabilization of the excited solute state with increasing solvent polarity. The bands are affected by specific solute-solvent interactions including hydrogen bond donor ability (acidity) and hydrogen bond acceptor ability (basicity) and nonspecific solute-solvent interactions including electromagnetic interaction between the dipole moments of solute and polar solvents.

icon graph This Abstract was viewed 381 times | icon graph Article PDF downloaded 167 times

How to Cite
Masoud, M. S.; Ali, A. E.; Elasala, G. S.; Elwardany, R. E. Spectroscopic Study of Solvent Effects on the Electronic Absorption Spectra of Morpholine and Its Complexes. Eur. J. Chem. 2023, 14, 53-64.

Article Details

Crossref - Scopus - Google - European PMC

[1]. Duhalde, V.; Lahille, B.; Camou, F.; Pédeboscq, S.; Pometan, J.-P. Bon usage des antibiotiques: étude prospective sur l'utilisation du linézolide dans un hôpital universitaire français. Pathol. Biol. (Paris) 2007, 55, 478-481.

[2]. Marcireau, C.; Guilloton, M.; Karst, F. In vivo effects of fenpropimorph on the yeast Saccharomyces cerevisiae and determination of the molecular basis of the antifungal property. Antimicrob. Agents Chemother. 1990, 34, 989-993.

[3]. de Almeida, K. J.; Ramalho, T. C.; Rinkevicius, Z.; Vahtras, O.; Agren, H.; Cesar, A. Theoretical study of specific solvent effects on the optical and magnetic properties of copper(II) acetylacetonate. J. Phys. Chem. A 2011, 115, 1331-1339.

[4]. Kosenkov, D.; Slipchenko, L. V. Solvent effects on the electronic transitions of p-nitroaniline: a QM/EFP study. J. Phys. Chem. A 2011, 115, 392-401.

[5]. Gülseven Sıdır, Y.; Sıdır, I.; Taşal, E.; Ermiş, E. Studies on the electronic absorption spectra of some monoazo derivatives. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2011, 78, 640-647.

[6]. Adegoke, O. A.; Idowu, O. S. Solvatochromic behaviours and structure-spectra relationships of 4-carboxyl-2,6-dinitrophenylazohydroxy naphthalenes. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2010, 75, 719-727.

[7]. Baughman, B. M.; Stennett, E.; Lipner, R. E.; Rudawsky, A. C.; Schmidtke, S. J. Structural and spectroscopic studies of the photophysical properties of benzophenone derivatives. J. Phys. Chem. A 2009, 113, 8011-8019.

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

[9]. Warde, U.; Sekar, N. Solvatochromic benzo[h] coumarins: Synthesis, solvatochromism, NLO and DFT study. Opt. Mater. (Amst.) 2017, 72, 346-358.

[10]. Masoud, M. S.; Shaker, M. A.; Ali, A. E.; Elasal, G. S. Solvatochromaticity and pH dependence of the electronic absorption spectra of some purines and pyrimidines and their metal complexes. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2011, 79, 538-547.

[11]. Van Uitert, L. G.; Haas, C. G. Studies on coördination compounds. I. a method for determining thermodynamic equilibrium constants in mixed Solvents1, 2. J. Am. Chem. Soc. 1953, 75, 451-455.

[12]. Masoud, M. S.; Ali, A. E.; Elasala, G. S.; Elwardany, R. E. Structural and thermal studies on some morpholine complexes. J. Mol. Struct. 2019, 1175, 648-662.

[13]. Knapp, J. S.; Emtiazl, G.; Yusoff, S.; Heron, S. T. The utilization of morpholine as a sole nitrogen source by Gram-negative bacteria. Letters in Applied Microbiology 1996, 23, 334-338.

[14]. Knapp, J. S.; Whytell, A. J. The biodegradation of morpholine in river water and activated sludge. Environ. Pollut. 1990, 68, 67-79.

[15]. Díaz, M. S.; Freile, M. L.; Gutiérrez, M. I. Solvent effect on the UV/Vis absorption and fluorescence spectroscopic properties of berberine. Photochem. Photobiol. Sci. 2009, 8, 970-974.

[16]. Hanesch; Scholger Mapping of heavy metal loadings in soils by means of magnetic susceptibility measurements. Environ. Geol. 2002, 42, 857-870.

[17]. Ahuja, I. S.; Singh, R. Morpholine complexes with divalent nickel thiocyanate. Transit. Met. Chem. 1977, 2, 132-135.

[18]. Ahuja, I. S.; Singh, R. Bidentate bridged morpholine complexes with zinc(II) and cadmium(II) cyanides. J. Coord. Chem. 1976, 5, 167-170.

[19]. Kramer, P.; Nowak, T. The preparation and characterization of Cr(III) and Co(III) complexes of GDP and GTP and their interactions with avian phosphoenolpyruvate carboxykinase. J. Inorg. Biochem. 1988, 32, 135-151.

[20]. Jogi, P.; Mounika, K.; Padmaja, M.; M., L.; Gyanakumari, C. Synthesis, characterization and antibacterial studies of some transition metal complexes of a Schiff base derived from 2-(aminomethyl)- benzimidazole and thiophene-2-carbaxaldehyde. E-J. Chem. 2011, 8, 1662-1669.

[21]. Tabbì, G.; Giuffrida, A.; Bonomo, R. P. Determination of formal redox potentials in aqueous solution of copper(II) complexes with ligands having nitrogen and oxygen donor atoms and comparison with their EPR and UV-Vis spectral features. J. Inorg. Biochem. 2013, 128, 137-145.

[22]. Figgins, P. E.; Busch, D. H. Complexes of Iron(II), Cobalt(II) and Nickel(II) with Biacetyl-bis-methylimine, 2-Pyridinal-methylimine and 2,6-Pyridindial-bis-methylimine. J. Am. Chem. Soc. 1960, 82, 820-824.

[23]. Anan, N. A.; Hassan, S. M.; Saad, E. M.; Butler, I. S.; Mostafa, S. I. Preparation, characterization and pH-metric measurements of 4-hydroxysalicylidenechitosan Schiff-base complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Ru(III), Rh(III), Pd(II) and Au(III). Carbohydr. Res. 2011, 346, 775-793.

[24]. Louis, C.; Che, M. EPR investigation of the coordination sphere of molybdenum(5+) ions on thermally reduced silica-supported molybdenum catalysts prepared by the grafting method. J. Phys. Chem. 1987, 91, 2875-2883.

[25]. Husain, M. M.; Sindhu, R.; Tandon, H. C. Determination of excited singlet-state dipole moments of hydroxy and methoxy coumarins using solvatochromic method. Eur. J. Chem. 2012, 3, 75-80.

[26]. George, J.; George, M.; Alex, J.; Sajan, D.; Shihab, N. K.; Vinitha, G.; Chitra, R. Growth of Morpholin-4-ium hydrogen tartrate single crystal for optical limiting application. Opt. Laser Technol. 2019, 119, 105647.

[27]. Airinei, A.; Homocianu, M.; Dorohoi, D. O. Changes induced by solvent polarity in electronic absorption spectra of some azo disperse dyes. J. Mol. Liq. 2010, 157, 13-17.

[28]. Iwanek, W.; Mattay, J. Ground state and excited state association: chiral recognition between 2,2′-dihydroxy-1,1′-binaphthyl and amines. J. Photochem. Photobiol. A Chem. 1992, 67, 209-226.

[29]. David, J. G.; Hallam, H. E. Infra-red solvent shifts and molecular interactions-X triatomic molecules, CS2, COS and SO2. Spectrochim. Acta A 1967, 23, 593-603.

[30]. Abe, T. Theory of solvent effects on molecular electronic spectra. Frequency shifts. Bull. Chem. Soc. Jpn. 1965, 38, 1314-1318.

[31]. Fowler, F. W.; Katritzky, A. R.; Rutherford, R. J. D. The correlation of solvent effects on physical and chemical properties. J. Chem. Soc. 1971, 460-469.

[32]. Hammud, H. H.; Ghannoum, A. M.; Fares, F. A.; Abramian, L. K.; Bouhadir, K. H. New 1,6-heptadienes with pyrimidine bases attached: Syntheses and spectroscopic analyses. J. Mol. Struct. 2008, 881, 11-20.

[33]. Asuero, A. G.; Sayago, A.; González, A. G. The correlation coefficient: An overview. Crit. Rev. Anal. Chem. 2006, 36, 41-59.

[34]. Husain, M. M.; Sindhu, R.; Tandon, H. C. Photophysical properties and estimation of ground and excited state dipole moments of 7-diethylamino and 7-diethylamino-4-methyl coumarin dyes from absorption and emission spectra. Eur. J. Chem. 2012, 3, 87-93.

[35]. Masoud, M. S.; Ali, A. E.; Ghareeb, D. A.; Nasr, N. M. Spectroscopic behavior and equilibrium studies of some metallocephalosporins. J. Mol. Liq. 2016, 224, 914-929.

[36]. Masoud, M. S.; Hindawy, A. M.; Soayed, A. A.; El-Kaway, M. Y. A. Changes induced by solvent polarity in electronic absorption spectra of some nucleic acid constituents. Fluid Phase Equilib. 2011, 312, 37-59.

[37]. Zuleta, J. A.; Bevilacqua, J. M.; Eisenberg, R. Solvatochromic and emissive properties of pt(II) complexes with 1,1- and 1,2-ditholates. Coord. Chem. Rev. 1991, 111, 237-248.

[38]. Golchoubian, H.; Moayyedi, G.; Rezaee, E.; Bruno, G. Synthesis, characterization and solvatochromism study of mixed-chelate copper(II) complexes: A combined experimental and density functional theoretical study. Polyhedron 2015, 96, 71-78.

[39]. Abu-Eittah, R. H.; Khedr, M. K. The electronic absorption spectra of pyridine azides, solvent-solute interaction. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2009, 71, 1688-1694.

[40]. Wang, P.; Anderko, A. Computation of dielectric constants of solvent mixtures and electrolyte solutions. Fluid Phase Equilib. 2001, 186, 103-122.

[41]. Laurence, C.; Nicolet, P.; Dalati, M. T.; Abboud, J.-L. M.; Notario, R. The empirical treatment of solvent-solute interactions: 15 years of .Pi. J. Phys. Chem. 1994, 98, 5807-5816.

[42]. Gálico, D. A.; Nova, C. V.; Guerra, R. B.; Bannach, G. Thermal and spectroscopic studies of the antioxidant food additive propyl gallate. Food Chem. 2015, 182, 89-94.

[43]. Osman, A.; Abu-Eittah, R. Complex formation between copper(II) and thiobarbiturates. J. Pharm. Sci. 1980, 69, 1164-1168.

[44]. Trišović, N.; Banjac, N.; Valentić, N.; Ušćumlić, G. Solvent effects on the structure-activity relationship of phenytoin-like anticonvulsant drugs. J. Solution Chem. 2009, 38, 199-208.

[45]. Sıdır, İ.; Taşal, E.; Gülseven, Y.; Güngör, T.; Berber, H.; Öğretir, C. Studies on solvatochromic behavior of some monoazo derivatives using electronic absorption spectra. Int. J. Hydrogen Energy 2009, 34, 5267-5273.

[46]. Ebead, Y. H.; Selim, M. A.; Ibrahim, S. A. Solvatochromic, acid-base features and time effect of some azo dyes derived from 1,3-benzothiazol-2-ylacetonitrile: experimental and semiempirical investigations. Spectrochim. Acta A Mol. Biomol. Spectrosc. 2010, 75, 760-768.

[47]. Chiappe, C.; Pieraccini, D. Ionic liquids: solvent properties and organic reactivity. J. Phys. Org. Chem. 2005, 18, 275-297.

[48]. Crowhurst, L.; Falcone, R.; Lancaster, N. L.; Llopis-Mestre, V.; Welton, T. Using Kamlet-Taft solvent descriptors to explain the reactivity of anionic nucleophiles in ionic liquids. J. Org. Chem. 2006, 71, 8847-8853.

[49]. Duereh, A.; Sato, Y.; Smith, R. L., Jr; Inomata, H. Analysis of the cybotactic region of two renewable lactone-water mixed-solvent systems that exhibit synergistic Kamlet-Taft basicity. J. Phys. Chem. B 2016, 120, 4467-4481.

[50]. Eto, M.; Tajiri, O.; Nakagawa, H.; Harano, K. Correlation of thione-to-thiol rearrangement rates of xanthates with solvent scales. Analysis of the reaction behavior by the Kamlet-Taft parameters, , α and β. Tetrahedron 1998, 54, 8009-8014.

[51]. Yazdanbakhsh, M. R.; Mohammadi, A. Synthesis, substituent effects and solvatochromic properties of some disperse azo dyes derived from N-phenyl-2, 2′-iminodiethanol. J. Mol. Liq. 2009, 148, 35-39.

[52]. Reichardt, C. Solvents and solvent effects: An introduction. Org. Process Res. Dev. 2007, 11, 105-113.

Supporting Agencies

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

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).