European Journal of Chemistry

4-Carboxyanilinium dihydrogen phosphate monohydrate, an organophosphate adducts of 4-amino benzoic acid: Structural, vibrational, thermal, and computational studies


Main Article Content

Lata Panicker


4-Carboxyanilinium dihydrogen phosphate monohydrate (4-CAH2PO4·H2O), an organophosphate adduct, was synthesized and characterized by single-crystal X-ray diffraction, Fourier transform infrared (FTIR), Differential scanning calorimetry (DSC) and computational analysis performed using CrystalExplorer 21, Gaussian 09W and Multiwfn 3.7 software. The complex 4-CAH2PO4·H2O crystallized in the triclinic space group, P-1, with two molecules each of 4-carboxyanilinium (4-CA) cations, H2PO4 anions, and water, respectively, in an asymmetric unit. Crystal data for C7H12NO7P: triclinic, space group P-1, a = 8.5238(2) Å, b = 8.9068(2) Å, c = 14.4976(4) Å, α = 106.456(2)°, β = 90.195(2)°, γ = 92.811(2)°, = 1054.13(5) Å3, Z = 4, T = 293 K, μ(Cu Kα) = 2.587 mm-1, Dcalc = 1.595 g/cm3, 18182 reflections measured (6.358° ≤ 2Θ ≤ 146.396°), 4149 unique (Rint = 0.1018, Rsigma = 0.0521) which were used in all calculations. The final R1 was 0.0584 (I > 2σ(I)) and wR2 was 0.1712 (all data). The organic layer containing 4-CA cations and the inorganic layer containing phosphate anions and water molecules in 4-CAH2PO4·H2O crystals are connected through a three-dimensional network of strong charge-assisted N–H···O and C-OH···O hydrogen bonds. The fingerprint plot of 4-CAH2PO4·H2O obtained indicated that the most prominent interaction corresponds to the short O···H contact, followed by the H···H and H···C contacts. The intermolecular interaction topology of 4-CAH2PO4·H2O has been quantitatively analyzed. The 4-CAH2PO4·H2O complex was optimized by density functional theory (DFT) with B3LYP/6-31G basis set and the theoretical IR vibrational spectra determined. The noncovalent interaction (NCI) and quantum theory of the atom in the molecule (QTAIM) analysis were done using Multiwfn 3.7 software. 4-CAH2PO4·H2O complex structure and its computational analysis are also compared with that of 4-carboxyanilinium dihydrogen phosphate (4-CAH2PO4).

icon graph This Abstract was viewed 124 times | icon graph Article PDF downloaded 29 times icon graph Article CIF FILE downloaded 0 times

How to Cite
Panicker, L. 4-Carboxyanilinium Dihydrogen Phosphate Monohydrate, an Organophosphate Adducts of 4-Amino Benzoic Acid: Structural, Vibrational, Thermal, and Computational Studies. Eur. J. Chem. 2024, 15, 1-16.

Article Details

Crossref - Scopus - Google - European PMC

[1]. Wojtaś, M.; Ga¸gor, A.; Czupiński, O.; Pietraszko, A.; Jakubas, R. 2,4,6-Trimethylpyridinium perchlorate: Polar properties and correlations with molecular structure of organic-inorganic hybrid crystal. J. Solid State Chem. 2009, 182, 3021-3030.

[2]. Parola, S.; Julián-López, B.; Carlos, L. D.; Sanchez, C. Optical properties of hybrid organic‐inorganic materials and their applications. Adv. Funct. Mater. 2016, 26, 6506-6544.

[3]. Dos Santos, L.; Macchi, P. The role of hydrogen bond in designing molecular optical materials. Crystals (Basel) 2016, 6, 43-56.

[4]. Thakuria, R.; Delori, A.; Jones, W.; Lipert, M. P.; Roy, L.; Rodríguez-Hornedo, N. Pharmaceutical cocrystals and poorly soluble drugs. Int. J. Pharm. 2013, 453, 101-125.

[5]. Bharate, S. S. Recent developments in pharmaceutical salts: FDA approvals from 2015 to 2019. Drug Discov. Today 2021, 26, 384-398.

[6]. Mahé, N.; Nicolaï, B.; Allouchi, H.; Barrio, M.; Do, B.; Céolin, R.; Tamarit, J.-L.; Rietveld, I. B. Crystal structure and solid-state properties of 3,4-diaminopyridine dihydrogen phosphate and their comparison with other diaminopyridine salts. Cryst. Growth Des. 2013, 13, 708-715.

[7]. Benali-Cherif, N.; Abouimrane, A.; Sbai, K.; Merazig, H.; Cherouana, A.; Bendjeddou, L. p-Carboxyphenylammonium dihydrogenmono phosphate monohydrate. Acta Crystallogr. Sect. E Struct. Rep. Online 2002, 58, o160-o161.

[8]. Benali-Cherif, N.; Direm, A.; Allouche, F.; Soudani, K. Hydrogen bonding in 4-carboxyanilinium dihydrogenphosphate. Acta Crystallogr. Sect. E Struct. Rep. Online 2007, 63, o2272-o2274.

[9]. Agilent (2015). CrysAlis PRO. Agilent Technologies Ltd, Yarnton, Oxfordshire, England.

[10]. Sheldrick, G. M. SHELXT- Integrated space-group and crystal-structure determination. Acta Crystallogr. A Found. Adv. 2015, 71, 3-8.

[11]. Sheldrick, G. M. Crystal structure refinement with SHELXL. Acta Crystallogr. C Struct. Chem. 2015, 71, 3-8.

[12]. Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A. K.; Puschmann, H. OLEX2: a complete structure solution, refinement and analysis program. J. Appl. Crystallogr. 2009, 42, 339-341.

[13]. Spackman, P. R.; Turner, M. J.; McKinnon, J. J.; Wolff, S. K.; Grimwood, D. J.; Jayatilaka, D.; Spackman, M. A. CrystalExplorer: a program for Hirshfeld surface analysis, visualization and quantitative analysis of molecular crystals. J. Appl. Crystallogr. 2021, 54, 1006-1011.

[14]. Turner, M. J.; Mckinnon, J. J.; Wolff, S. K.; Grimwood, D. J.; Spackman, P. R.; Jayatilaka, D.; Spackman, M. A. (2017) CrystalExplorer 21, University of Western Australia, Perth, Australia.

[15]. McKinnon, J. J.; Spackman, M. A.; Mitchell, A. S. Novel tools for visualizing and exploring intermolecular interactions in molecular crystals. Acta Crystallogr. B 2004, 60, 627-668.

[16]. Spackman, M. A.; Jayatilaka, D. Hirshfeld surface analysis. CrystEngComm 2009, 11, 19-32.

[17]. Spackman, M. A.; McKinnon, J. J. Fingerprinting intermolecular interactions in molecular crystals. CrystEngComm 2002, 4, 378-392.

[18]. Turner, M. J.; Grabowsky, S.; Jayatilaka, D.; Spackman, M. A. Accurate and efficient model energies for exploring intermolecular interactions in molecular crystals. J. Phys. Chem. Lett. 2014, 5, 4249-4255.

[19]. Mackenzie, C. F.; Spackman, P. R.; Jayatilaka, D.; Spackman, M. A. CrystalExplorermodel energies and energy frameworks: extension to metal coordination compounds, organic salts, solvates and open-shell systems. IUCrJ 2017, 4, 575-587.

[20]. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, J. A.; Vreven, T.; Kudin, K. N.; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.; Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; Pople, J. A. Gaussian 09, Revision A.02, Gaussian, Inc., Wallingford CT, 2009.

[21]. Dennington, R.; Keith, T. A.; Millam, J. M. GaussView, Version 6, Semichem Inc.; Shawnee Mission, KS, 2016.

[22]. Becke, A. D. A new mixing of Hartree-Fock and local density-functional theories. J. Chem. Phys. 1993, 98, 1372-1377.

[23]. Becke, A. D. Density-functional exchange-energy approximation with correct asymptotic behavior. Phys. Rev. A Gen. Phys. 1988, 38, 3098-3100.

[24]. Lu, T.; Chen, F. Multiwfn: A multifunctional wavefunction analyzer. J. Comput. Chem. 2012, 33, 580-592.

[25]. Johnson, C. K. (1976). ORTEPII. Report ORNL-5138. Oak Ridge National Laboratory, Tennessee, USA.

[26]. Panicker, L.; Thomas, S. P.; Wadawale, A.; Girija, K. G.; Row, T. N. G. Reversible order-disorder phase transition and interaction topology in 4-carboxyanilinium nitrate. J. Mol. Struct. 2021, 1227, 129542.

[27]. Benali-Cherif, N.; Direm, A.; Allouche, F.; Boukli-H-Benmenni, L.; Soudani, K. 4-Carboxyanilinium hydrogensulfate. Acta Crystallogr. Sect. E Struct. Rep. Online 2007, 63, o2054-o2056.

[28]. Świsłocka, R.; Samsonowicz, M.; Regulska, E.; Lewandowski, W. Molecular structure of 4-aminobenzoic acid salts with alkali metals. J. Mol. Struct. 2006, 792-793, 227-238.

[29]. Samsonowicz, M.; Hrynaszkiewicz, T.; Świsłocka, R.; Regulska, E.; Lewandowski, W. Experimental and theoretical IR, Raman, NMR spectra of 2-, 3- and 4-aminobenzoic acids. J. Mol. Struct. 2005, 744-747, 345-352.

[30]. Versányi, G. Assignments for Vibrational Spectra of 700 Benzene Derivatives, Akademiai Kiado, Budapest, Hungary, 1973.

[31]. Nakamoto, K. Infrared and Raman spectra of inorganic and coordination compounds: Part A: Theory and applications in inorganic chemistry; Wiley: Hoboken, NJ, USA, 2008.

[32]. Oubouaza, R.; Benson, M.; Wojciechowski, J.; Chtita, S.; Tridane, M.; Belaaouad, S. Synthesis, crystal structure, vibrational study and DFT computation of barium dihydrogenomonophosphate Ba(H2PO4)2. Biointerface Res. Appl. Chem. 2021, 12, 1120-1133.

[33]. Robertson, W. H.; Johnson, M. A. Molecular aspects of Halide ion hydration: The cluster approach. Annu. Rev. Phys. Chem. 2003, 54, 173-213.

[34]. Klähn, M.; Mathias, G.; Kötting, C.; Nonella, M.; Schlitter, J.; Gerwert, K.; Tavan, P. IR spectra of phosphate ions in aqueous solution: Predictions of a DFT/MM approach compared with observations. J. Phys. Chem. A 2004, 108, 6186-6194.

[35]. Baril, J.; Max, J.-J.; Chapados, C. Titrage infrarouge de l'acide phosphorique. Can. J. Chem. 2000, 78, 490-507.

[36]. Panicker, L. 4-Carboxyanilinium phosphite: A structural, vibrational, thermal and computational study. J. Mol. Struct. 2023, 1288, 135773.

[37]. Panicker, L. Structural, vibrational and thermal study of Bis(4-Carboxyanilinium) sulphate a new organo-sulphate adduct of 4-amino benzoic acid. J. Mol. Struct. 2022, 1267, 133631.

[38]. Panicker, L. Structural, vibrational, thermal and computational studies of new organo-selenate compounds bis(4-carboxyanilinium) selenate and bis(4-carboxyanilinium) selenate trihydrate. J. Mol. Struct. 2024, 1296, 136764.

[39]. Tamer, Ö.; Sefa Atalay, A.; Avci, D.; Atalay, Y.; Tarcan, E.; Marchewka, M. K. Optimized geometry, vibration (IR and Raman) spectra and nonlinear optical activity of p-nitroanilinium perchlorate molecule: A theoretical study. Mater. Sci.-Pol. 2016, 34, 192-203.

[40]. Mohankumar, V.; Karunagaran, N.; Pandian, M. S.; Ramasamy, P. Density functional theory calculations and Hirshfeld surface analysis of propyl-para-hydroxybenzoate (PHB) for optoelectronic application. Mater. Sci.-Pol. 2020, 38, 386-393.

[41]. Johnson, E. R.; Keinan, S.; Mori-Sánchez, P.; Contreras-García, J.; Cohen, A. J.; Yang, W. Revealing noncovalent interactions. J. Am. Chem. Soc. 2010, 132, 6498-6506.

[42]. Humphrey, W.; Dalke, A.; Schulten, K. VMD: Visual molecular dynamics. J. Mol. Graph. 1996, 14, 33-38.

[43]. Bader, R. F. W. Atoms in Molecules: A Quantum Theory; Clarendon Press: Oxford, England, 1994.

[44]. Koch, U.; Popelier, P. L. A. Characterization of C-H-O hydrogen bonds on the basis of the charge density. J. Phys. Chem. 1995, 99, 9747-9754.

[45]. Yang, Y.-Z.; Liu, X.-F.; Zhang, R.-B.; Pang, S.-P. Joint experimental and theoretical studies of the surprising stability of the aryl pentazole upon noncovalent binding to β-cyclodextrin. Phys. Chem. Chem. Phys. 2017, 19, 31236-31244.

[46]. Emamian, S.; Lu, T.; Kruse, H.; Emamian, H. Exploring nature and predicting strength of hydrogen bonds: A correlation analysis between atoms‐in‐molecules descriptors, binding energies, and energy components of symmetry‐adapted perturbation theory. J. Comput. Chem. 2019, 40, 2868-2881.

[47]. Rozas, I.; Alkorta, I.; Elguero, J. Behavior of ylides containing N, O, and C atoms as hydrogen bond acceptors. J. Am. Chem. Soc. 2000, 122, 11154-11161.

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).