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Al-Hazmi GH, Hassanien A, Atta A, Refat MS, Saad HA, Shakya S, Adam AMA. Supramolecular charge-transfer complex generated by the interaction between tin(II) 2,3-naphtalocyanine as a donor with DDQ as an acceptor: Spectroscopic studies in solution state and theoretical calculations. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Adam AMA, Saad HA, Refat MS, Hegab MS, Al-Hazmi GH, Mohammed Alsuhaibani A, Mohamed H. The derivation and characterization of quinine charge-transfer complexes with inorganic and organic acceptors in liquid and solid form. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Adam AMA, Altalhi TA, Saad HA, Alsuhaibani AM, Refat MS, Hegab MS. Correlations between spectroscopic data for charge-transfer complexes of two artificial sweeteners, aspartame and neotame, generated with several π-acceptors. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115904] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Exploring the charge-transfer chemistry of fluorine-containing pyrazolin-5-ones: The complexation of 1-methyl-3-trifluoromethyl-2-pyrazoline-5-one with five π-acceptors. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115814] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Adam AMA, Saad HA, Alsuhaibani AM, Refat MS, Hegab MS. Charge-transfer chemistry of azithromycin, the antibiotic used worldwide to treat the coronavirus disease (COVID-19). Part II: Complexation with several π-acceptors (PA, CLA, CHL). J Mol Liq 2021; 325:115121. [PMID: 33518854 PMCID: PMC7837197 DOI: 10.1016/j.molliq.2020.115121] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/10/2020] [Accepted: 12/17/2020] [Indexed: 12/27/2022]
Abstract
Finding a vaccine or cure for the coronavirus disease (COVID-19) responsible for the worldwide pandemic and its economic, medical, and psychological burdens is one of the most pressing issues presently facing the global community. One of the current treatment protocols involves the antibiotic azithromycin (AZM) alone or in combination with other compounds. Obtaining additional insight into the charge-transfer (CT) chemistry of this antibiotic could help researchers and clinicians to improve such treatment protocols. Toward this aim, we investigated the CT interactions between AZM and three π-acceptors: picric acid (PA), chloranilic acid (CLA), and chloranil (CHL) in MeOH solvent. AZM formed colored products at a 1:1 stoichiometry with the acceptors through intermolecular hydrogen bonding. An n → π* interaction was also proposed for the AZM-CHL CT product. The synthesized CT products had markedly different morphologies from the free reactants, exhibiting a semi-crystalline structure composed of spherical particles with diameters ranging from 50 to 90 nm.
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Affiliation(s)
- Abdel Majid A Adam
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Hosam A Saad
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Amnah M Alsuhaibani
- Department of Physical Sport Science, Princess Nourah bint Abdulrahman University, 4545 - King Khalid Airport Unit No. 1, Riyadh 13415-7132, Saudi Arabia
| | - Moamen S Refat
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Mohamed S Hegab
- Deanship of Supportive Studies (D.S.S.), Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
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Adam AMA, Saad HA, Alsuhaibani AM, Refat MS, Hegab MS. Charge-transfer chemistry of azithromycin, the antibiotic used worldwide to treat the coronavirus disease (COVID-19). Part I: Complexation with iodine in different solvents. J Mol Liq 2021; 325:115187. [PMID: 33390633 PMCID: PMC7764390 DOI: 10.1016/j.molliq.2020.115187] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/14/2020] [Accepted: 12/22/2020] [Indexed: 12/24/2022]
Abstract
Around the world, the antibiotic azithromycin (AZM) is currently being used to treat the coronavirus disease (COVID-19) in conjunction with hydroxychloroquine or chloroquine. Investigating the chemical and physical properties of compounds used alone or in combination to combat the COVID-19 pandemic is of vital and pressing importance. The purpose of this study was to characterize the charge transfer (CT) complexation of AZM with iodine in four different solvents: CH2Cl2, CHCl3, CCl4, and C6H5Cl. AZM reacted with iodine at a 1:1 M ratio (AZM to I2) in the CHCl3 solvent and a 1:2 M ratio in the other three solvents, as evidenced by data obtained from an elemental analysis of the solid CT products and spectrophotometric titration and Job's continuous variation method for the soluble CT products. Data obtained from UV-visible and Raman spectroscopies indicated that AZM strongly interacted with iodine in the CH2Cl2, CCl4, and C6H5Cl solvents by a physically potent n→σ* interaction to produce a tri-iodide complex formulated as [AZM·I+]I3 -. XRD and TEM analyses revealed that, in all solvents, the AZM-I2 complex possessed an amorphous structure composed of spherical particles ranging from 80 to 110 nm that tended to aggregate into clusters. The findings described in the present study will hopefully contribute to optimizing the treatment protocols for COVID-19.
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Affiliation(s)
- Abdel Majid A Adam
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Hosam A Saad
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Amnah M Alsuhaibani
- Department of Physical Sport Science, Princess Nourah bint Abdulrahman University, 4545 - King Khalid Airport Unit No. 1, Riyadh 13415-7132, Saudi Arabia
| | - Moamen S Refat
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Mohamed S Hegab
- Deanship of Supportive Studies (D.S.S.), Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
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Balraj C, Balaji S, Karthikeyan M. Systematic measurements of charge transfer complexes caused from 1-phenyl-1,2,3,4-tetrahydroisoquinoline and 4-aminoacetanilide with series of π-acceptors (BQ, DDQ, TCNQ). SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 245:118931. [PMID: 32950855 DOI: 10.1016/j.saa.2020.118931] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/04/2020] [Accepted: 09/05/2020] [Indexed: 06/11/2023]
Abstract
Molecular charge-transfer interaction of a series of electron π-acceptors of 1,4-benzoquinone (BQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and Tetracyanoquinodimethane (TCNQ) with selected donors of 1-phenyl-1,2,3,4-tetrahydroisoquinoline (PTHIQ) and 4-aminoacetanilide (ACE) have been studied in methanol at room temperature. The stoichiometry of the complexes was determined by photometric titration method and was found to be 1:1, in all the cases. Spectro-kinetic interaction studies along with rate constants and observed formation constants (K) indicated that the strength of the complex formations is PTHIQ-BQ < PTHIQ-DDQ < PTHIQ-TCNQ. Also, Similar observations happened in ACE-BQ and < ACE-DDQ < ACE-TCNQ systems. FT-IR results indicated that the point of interaction was identifying in NH moiety of PTHIQ and NH2 moiety of ACE with series of π-acceptor complexes. The experimental results were compared with Ab initio DFT calculations at the B3LYP/6-31 + G(d) level of theory. The increasing order of the experimentally measured formation constant of CT-complexes (PTHIQ and ACE with series of acceptors) was well supported by theoretical HOMO-LUMO energy gap and drastically changes in Mulliken charges of NH moiety of PTHIQ, NH2 moiety of ACE with complexation with acceptors.
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Affiliation(s)
- C Balraj
- Department of Chemistry, Kongu Engineering College (Autonomous), Perundurai, Erode 638060, India.
| | - S Balaji
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India
| | - M Karthikeyan
- Department of Chemistry, Kongu Engineering College (Autonomous), Perundurai, Erode 638060, India
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Ganesh K, Balraj C, Satheshkumar A, Elango KP. Spectroscopic studies on the formation of charge transfer complexes of l-phenylalanine with 2,3,5-trichloro-6-alkoxy-1,4-benzoquinones in aqueous medium. ARAB J CHEM 2019. [DOI: 10.1016/j.arabjc.2014.10.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Satheshkumar A, Elango KP. Spectroscopic and molecular docking studies on the charge transfer complex of bovine serum albumin with quinone in aqueous medium and its influence on the ligand binding property of the protein. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 130:337-343. [PMID: 24802718 DOI: 10.1016/j.saa.2014.03.108] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 03/25/2014] [Accepted: 03/29/2014] [Indexed: 06/03/2023]
Abstract
The spectral techniques such as UV-Vis, (1)H NMR and fluorescence and electrochemical experiments have been employed to investigate the interaction between 2-methoxy-3,5,6-trichloro-1,4-benzoquinone (MQ; a water soluble quinone) and bovine serum albumin (BSA) in aqueous medium. The fluorescence of BSA was quenched by MQ via formation of a 1:1 BSA-MQ charge transfer adduct with a formation constant of 3.3×10(8) L mol(-1). Based on the Forster's theory the binding distance between them is calculated as 2.65 nm indicating high probability of binding. For the first time, influence of quinone on the binding property of various types of ligands such as aspirin, ascorbic acid, nicotinimide and sodium stearate has also been investigated. The results indicated that the strong and spontaneous binding existing between BSA and MQ, decreased the intensity of binding of these ligands with BSA. Since Tryptophan (Trp) is the basic residue present in BSA, a comparison between binding property of Trp-MQ adduct with that of BSA-MQ with these ligands has also been attempted. 1H NMR titration study indicated that the Trp forms a charge transfer complex with MQ, which reduces the interaction of Trp with the ligands. Molecular docking study supported the fact that the quinone interacts with the Trp212 unit of the BSA and the free energy change of binding (ΔG) for the BSA-MQ complex was found to be -46 kJ mol(-1), which is comparable to our experimental free energy of binding (-49 kJ mol(-1)) obtained from fluorescence study.
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Affiliation(s)
- Angupillai Satheshkumar
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624302, India
| | - Kuppanagounder P Elango
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624302, India.
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Ganesh K, El-Mossalamy EH, Satheshkumar A, Balraj C, Elango KP. Molecular complexes of l-phenylalanine with substituted 1,4-benzoquinones in aqueous medium: spectral and theoretical investigations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 116:301-310. [PMID: 23973571 DOI: 10.1016/j.saa.2013.07.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/29/2013] [Accepted: 07/16/2013] [Indexed: 06/02/2023]
Abstract
Various spectral techniques such as UV-Vis, FT-IR, and fluorescence have been employed to investigate the charge transfer interaction of L-phenylalanine (LPA) with substituted 1,4-benzoquinones (MQ(1-4)). Kinetic and thermodynamic properties of the complexes were determined in aqueous medium at physiological condition (pH=7). The interaction of MQ(1-4) with L-phenylalanine (LPA) was found to proceed through the formation of donor-acceptor complex, yielding a radical anion. The stoichiometry of the complexes was determined by Jobs continuous variation method and was found to be 1:1 in all the cases. Fluorescence quenching studies showed that the interaction between the donor and the acceptors is spontaneous. The results indicated that the progressive replacement of chlorine atom (-I effect) by methoxy group (+M effect) in the quinone decreased the electron acceptor property of the quinone. The order of the experimentally measured association constant of these complexes was well supported by DFT/B3LYP calculations.
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Affiliation(s)
- K Ganesh
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624 302, India
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Balraj C, Satheshkumar A, Ganesh K, El-Mossalamy E, Elango K. Synthesis and characterization of molecular complexes of cimetidine with water soluble 1,4-benzoquinones. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2013.07.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Balraj C, Satheshkumar A, Ganesh K, Elango KP. Charge transfer complexes of quinones in aqueous medium: spectroscopic and theoretical studies on interaction of cimetidine with novel substituted 1,4-benzoquinones and its application in colorimetric sensing of anions. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 114:256-266. [PMID: 23770513 DOI: 10.1016/j.saa.2013.05.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 05/13/2013] [Indexed: 06/02/2023]
Abstract
For the first time, the charge transfer (CT) complexes of quinones in aqueous medium have been reported. A series of novel water soluble 1,4-benzoquinones possessing variable number of chloro and methoxy substituents has been employed as electron acceptors (MQ1-4) in the CT complexation with cimetidine (CTD) drug. The mechanism of the interaction has been investigated using various spectral techniques such as UV-Vis, (1)H NMR and FT-IR spectra. The rate of the CT interaction was observed to decrease with progressive replacement of chloro by methoxy substituent in the quinone and this variation is well supported by the formation constant and enthalpy of activation values. Ab initio DFT calculations predicted that the variation in the bond lengths of the carbonyl moieties and the charge densities on the carbonyl oxygen atoms depend largely on the nature of the substituent present in the quinone ring. Also, the HOMO(Donor)-LUMO(Acceptor) energy gaps correlate linearly with the formation constants of the CT complex. The equilibrium, kinetic, electrochemical and theoretical investigations of the CT interaction of these quinones indicated that progressive replacement of electron withdrawing chlorine atom (-I effect) by an electron releasing methoxy group (+M effect) makes these acceptors progressively weaker. The charge-transfer complex, formed between CTD and monomethoxy quinone derivative, has been employed as a new class of chromogenic sensor for the colorimetric sensing of fluoride and acetate ions.
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Affiliation(s)
- C Balraj
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram, India
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Ganesh K, Satheshkumar A, Balraj C, Elango KP. Substituent effect on the electron acceptor property of 1,4-benzoquinone towards the formation of molecular complex with sulfamethoxazole. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 107:156-166. [PMID: 23416920 DOI: 10.1016/j.saa.2013.01.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 12/28/2012] [Accepted: 01/10/2013] [Indexed: 06/01/2023]
Abstract
UV-Vis, (1)H NMR, FT-IR, LC-MS and fluorescence spectral techniques were employed to investigate the mechanism of interaction of sulfamethoxazole with varying number of methoxy/chloro substituted 1,4-benzoquinones (MQ1-4) and to characterize the reaction products. The interactions of MQ1-4 with sulfamethoxazole (SULF) were found to proceed through the formation of a donor-acceptor complex, containing radical anion and its conversion to the product. Fluorescence quenching studies showed that the interaction between the donor and the acceptors are spontaneous. The results indicated that the progressive replacement of chlorine atom (-I effect) by methoxy group (+M effect) in the quinone decreased the electron acceptor property of the quinone. The results of the correlation of experimentally measured binding constants with electrochemical data and ab initio DFT calculations supported these observations.
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Affiliation(s)
- K Ganesh
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624 302, India
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Balraj C, Satheshkumar A, Ganesh K, Elango KP. Spectral and theoretical studies on the molecular complexes of azacyclonol with new π-acceptors, alkoxysubstituted 1,4-benzoquinones. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.09.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ungurean A, Leopold N, David L, Chiş V. Vibrational spectroscopic and DFT study of trimethoprim. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 102:52-58. [PMID: 23220519 DOI: 10.1016/j.saa.2012.10.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 10/10/2012] [Accepted: 10/12/2012] [Indexed: 06/01/2023]
Abstract
Structural investigations by different vibrational spectroscopic methods: FTIR, FT-Raman and surface-enhanced Raman scattering (SERS) spectroscopy, as well as density functional theory (DFT) calculations were performed on trimethoprim (5-(3,4,5-trimethoxybenzyl)pyrimidine-2,4-diamine). A reliable assignment of vibrational IR, Raman and SERS bands was possible by a proper choice of model used in quantum chemical calculations. Based on SERS spectrum analysis it is shown that the molecule is adsorbed on the silver surface through the pyrimidine ring, in a perpendicular orientation. Two theoretical models were used in order to simulate the silver surface and the interaction with trimethoprim molecule, the accuracy of the models being evaluated by comparing the predicted bands position of the two complexes with the SERS result.
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Affiliation(s)
- Alia Ungurean
- Faculty of Physics, Babeş-Bolyai University, Kogălniceanu 1, 400084 Cluj-Napoca, Romania
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Ganesh K, Balraj C, Satheshkumar A, Elango K. Spectroscopic studies on the formation of molecular complexes of sulfamethoxazole with novel 2,3,5-trichloro-6-alkoxy-1,4-benzoquinones. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.09.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Supramolecular Arrangement in Styphnic Acid and Naphthalene-1,4-diol (1 : 1) through a Novel Synthetic Rote for Styphnic Acid. J CHEM-NY 2013. [DOI: 10.1155/2013/107515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The chemical preparation and crystal structure of styphnic acid and naphthalene-1,4-diol (1 : 1) (I) have been reported. The compound crystallizes in the orthorhombic system in space group Pnma and cell parametersa=6.6712(2),b=16.8267(7),c=13.6450(5) ÅandV=1531.71(10) Å3, andZ=4. Crystal structure has been determined and refined toR=0.0576. The crystal structure of I, the asymmetric unit, contains C6H2N3O7, C10H7O, and it is a half portion of both styphnic acid and naphthalene-1,4-diol. The O1–H1⋯O2 intramolecular hydrogen bond was found between the O–H and a nitro group in the styphnic acid unit.
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Ganesh K, Elango KP. Spectroscopic and spectrofluorimetric studies on the interaction of albendazole and trimethoprim with iodine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 93:185-197. [PMID: 22481175 DOI: 10.1016/j.saa.2012.03.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 01/21/2012] [Accepted: 03/03/2012] [Indexed: 05/31/2023]
Abstract
Raman, UV-vis, FT-IR, and fluorescence spectral techniques were employed to investigate the mechanism of interaction of albendazole (ALB) and trimethoprim (TMP) drugs with iodine. Interactions of ALB and TMP with iodine yields triiodide ion and its formation was confirmed by electronic and Raman spectra. The peaks appeared in Raman spectra of the isolated products are at around 145, 113 and 82 cm(-1) are assigned to ν(as)(I-I), ν(s)(I-I) and δ(I(3)(-)) respectively, confirmed the presence of I(3)(-) ion. Formation constant (K), molar extinction coefficient (ɛ) and thermodynamic properties ΔH(#), ΔS(#) and ΔG(#) were determined and discussed. Fluorescence quenching studies indicated that the interaction between the ALB, TMP with iodine are spontaneous and the TMP-iodine interaction is found to be stronger than that the other system. Solvent variation studies indicated that the binding constant increased with an increase in polarity of the medium.
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Affiliation(s)
- K Ganesh
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624 302, India
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Balraj C, Elango KP. Spectroscopic studies on the intermolecular charge transfer interaction of Fe(II)- and Fe(III)-phthalocyanines with 2,3,5,6-tetrachloro-1,4-benzoquinone and its application in colorimetric sensing of amino acids and amines. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 86:44-50. [PMID: 22074888 DOI: 10.1016/j.saa.2011.09.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/17/2011] [Accepted: 09/27/2011] [Indexed: 05/31/2023]
Abstract
The interactions of Fe(II)Pc and Fe(III)Pc with π-acceptor 2,3,5,6-tetrachloro-1,4-benzoquinone (p-chloranil, p-CHL) have been investigated spectroscopically (UV/vis and FT-IR) and spectrofluorimetrically at three different temperatures. The stoichiometry of the complexes was found to be 1:1. The results of electronic spectral studies indicated that the formation constant for Fe(II)Pc-p-CHL system is found to be higher than that for Fe(III)Pc-p-CHL system. This observation is well supported by the results of fluorescence quenching studies and the association constants calculated for Fe(II)Pc-p-CHL system is 4.2 × 10(3) mol L(-1) and that for Fe(III)Pc-p-CHL system is 2.2 × 10(3) mol L(-1). The data are discussed in terms of physico-chemical parameters viz. molar extinction coefficient, oscillator strength, dipole moment, ionization potential, dissociation energy and thermodynamic parameters. The results indicated that the formation of π-π CT complex is spontaneous and endothermic. Preliminary studies indicated that the CT complex can effectively be used as a colorimetric agent for sensing amino acids and amines.
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Affiliation(s)
- Chellamuthu Balraj
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624 302, India
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Balraj C, Satheshkumar A, Ganesh K, Elango KP. Spectral, electrochemical and theoretical studies on the charge transfer complexes of azacyclonol with novel substituted 1,4-benzoquinones possessing tunable electron acceptor properties. RSC Adv 2012. [DOI: 10.1039/c2ra20985c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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