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Cheng Z, Fan Y, Zhang L, Wang C. Preparation of co-enhanced gold nanoclusters and its application in the detections of 4-hexylresorcinol and Cr6++. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.134712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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S C, H R D, Melavanki R, Basanagouda MM, Mogurampelly S, J T. Computational and spectroscopic studies of biologically active coumarin-based fluorophores. LUMINESCENCE 2020; 36:769-787. [PMID: 33370866 DOI: 10.1002/bio.4002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 12/03/2020] [Accepted: 12/23/2020] [Indexed: 12/24/2022]
Abstract
We used density functional theory (DFT) calculations to examine the various molecular properties of two coumarin derivatives, namely 4-(5-amino-[1,3,4]thiadiazol-2-ylsulfanylmethyl)-7-methyl-chromen-2-one and 4-(5-amino-[1,3,4]thiadiazol-2-ylsulfanylmethyl)-7-methoxy-chromen-2-one at different levels of theory and basis sets. The calculated highest occupied molecular orbital and lowest unoccupied molecular orbital energies revealed that the investigated molecules were chemically active with a tendency for molecular interactions. The theoretical vibrational frequencies of these molecules were found to be consistent with the experimentally obtained frequencies. Moreover, solvatochromic measurements indicated no significant change in absorption spectral peak by varying the polarity of solvent. Under the same conditions we found that there was a red shift of 39 nm in the fluorescence spectral peak with increase in solvent polarity. The solvatochromic data were used to estimate excited dipole moments and the change in dipole moment was interpreted based on resonance structure of molecules.
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Affiliation(s)
- Chandrasekhar S
- Department of Physics, B N M Institute of Technology, Bangalore, India
| | - Deepa H R
- Department of Physics, B N M Institute of Technology, Bangalore, India
| | - Raveendra Melavanki
- Department of Physics, M S Ramaiah Institute of Technology, Bangalore, Karnataka, 560054, India
| | - Mahanthesh M Basanagouda
- P.G. Department of Studies in Chemistry, K.L.E. Society's P.C. Jabin Science College, Hubli, India
| | | | - Thipperudrappa J
- Department of Studies in Physics, Vijayanagara Sri Krishnadevaraya University, Ballari, India
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Ermakova EV, Arslanov VV. Analytical micelles containing amphiphilic aminoanthraquinone solvatochromic reporter receptor. COLLOID JOURNAL 2017. [DOI: 10.1134/s1061933x17060060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Comparative stability-indicating chromatographic methods for determination of 4-hexylresorcinol in pharmaceutical formulation and shrimps. J Pharm Biomed Anal 2017; 145:386-398. [PMID: 28719813 DOI: 10.1016/j.jpba.2017.06.065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 06/25/2017] [Accepted: 06/29/2017] [Indexed: 11/24/2022]
Abstract
Three chromatographic stability-indicating methods were developed for determination of 4-hexylresorcinol in pure form and in a pharmaceutical formulation. Method A was based on a gradient elution liquid chromatographic HPLC determination of 4-hexylresorcinol, its related impurities and in presence of its degradation products. UPLC-MS/MS (Method B) was described for determination of the cited drug in presence of its degradation products. Method C was a thin- layer chromatography (TLC)-densitometry method for the separation and determination of the active ingredient, one of its related impurities and in presence of its degradation products. The mechanism of alkali, oxidative and photodegradation of 4-hexylresorcinol was studied according to ICH guidelines. The degradation products were characterized by the LC-MS/MS method. Methods A and B were applicable for determination of 4-hexylresorcinol residues in shrimp meat. The studied drug was easily degraded in alkali medium giving toxic compounds. The results obtained by the proposed methods were statistically analyzed and compared with those obtained by applying a reported method.
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Zhang T, Zhu J, Zhai Y, Wang H, Bai X, Dong B, Wang H, Song H. A novel mechanism for red emission carbon dots: hydrogen bond dominated molecular states emission. NANOSCALE 2017; 9:13042-13051. [PMID: 28836649 DOI: 10.1039/c7nr03570e] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Carbon dots (CDs) have emerged as novel fluorescent probes due to their remarkable optical properties; however, red emission is still rare, has a relatively low efficiency, and its mechanism remains ambiguous. Herein, relatively efficient red-emission CDs based on p-phenylenediamine were prepared through various solvothermal means, where the highest quantum yield approached 41.1% in n-amyl alcohol, which was the most efficient quantum yield reported to date. Various structural characterizations were performed and confirmed that the red emission originated from the molecular states consisting of a nitrogen-containing organic fluorophore. The CDs were dispersed in different organic solvents and showed tunable emission, evolving from green to orange-red in aprotic solvents and a red emission in protic solvents. Further solvent correlation studies indicated that the hydrogen bond effect between the CDs and solvents was the main mechanism leading to the spectral shift. Accordingly, solid-state luminescent CDs-polymers were fabricated, which also demonstrated continuously tunable emission properties. This work opens a new window for recognizing the generation of tunable and red-emission CDs.
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Affiliation(s)
- Tianxiang Zhang
- State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China.
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Y TV, Agarwal DS, Sarmah A, Yukti, Sakhuja R, Pant DD. Design and synthesis of amino acid appended azo dye hybrid: Characterization, solvatochromic and quantum-chemical calculations using experimental and theoretical approach. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.06.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Thipperudrappa J, Raghavendra UP, Basanagouda M. Photophysical characteristics of biologically active 4-aryloxymethyl coumarins 4PTMBC and 1IPMBC. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 136 Pt C:1475-1483. [PMID: 25459709 DOI: 10.1016/j.saa.2014.10.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 07/21/2014] [Accepted: 10/13/2014] [Indexed: 06/04/2023]
Abstract
The absorption and fluorescence characteristics of biologically active coumarin derivatives 4-p-tolyloxymethyl-benzo[h]coumarin (4PTMBC) and 1-(4-iodo phenoxymethyl)-benzo[f]coumarin (1IPMBC) are studied at room temperature in a series of organic solvents and 1,4-dioxane - acetonitrile solvent mixture. The effect of pure solvents on the spectral properties are analyzed using Lippert-Mataga polarity function, Reichardt's microscopic solvent polarity parameter, Kamlet's and Catalan's multiple linear regression approaches. Both general solute - solvent interactions and hydrogen bonding interactions are operative in these systems. However, the contribution of hydrogen bonding interactions is less compared to general solute-solvent interactions. The solvatochromic correlations are used to estimate excited state dipole moment using experimentally determined ground state dipole moment. The bathochromic shift of the emission spectra and the increase in excited state dipole moment indicate the intramolecular charge transfer (ICT) character in the emitting singlet state. The solvation studies in 1,4-dioxane - acetonitrile solvent mixture suggest that these dyes are preferentially solvated by 1,4-dioxane.
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Affiliation(s)
- J Thipperudrappa
- Department of Physics, B.N.M. Institute of Technology, Bangalore 560 070, India.
| | - U P Raghavendra
- Department of Physics, Bangalore Institute of Technology, Bangalore 560 004, India
| | - Mahantesha Basanagouda
- P.G. Department of Studies in Chemistry, K.L.E. Society's P.C. Jabin Science College, Hubli 580 031, India
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Raghavendra U, Basanagouda M, Melavanki R, Fattepur R, Thipperudrappa J. Solvatochromic studies of biologically active iodinated 4-aryloxymethyl coumarins and estimation of dipole moments. J Mol Liq 2015. [DOI: 10.1016/j.molliq.2014.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Nagaraja D, Melavanki RM, Patil NR, Kusanur RA. Solvent effect on the relative quantum yield and fluorescence quenching of 2DAM. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 130:122-8. [PMID: 24769383 DOI: 10.1016/j.saa.2014.03.063] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 03/01/2014] [Accepted: 03/21/2014] [Indexed: 05/06/2023]
Abstract
The relative quantum yield of diethyl 2-acetamido-2-((3-oxo-3H-benzo[f]chromen-1-yl)methyl)malonate [2DAM] is estimated using single point method with quinine sulfate as standard reference. The quantum yield varies between 0.1161 and 0.3181 depending on the nature of the solvent. The rates of radiative and non radiative decay constants are also calculated. The fluorescence quenching of [2DAM] by aniline is studied at room temperature, by steady state, in five different solvents namely acetonitrile (AN), 1,4 dioxane (DX), 1,2 dichloroethane (DCE), tetrahydrofuran (THF) and toluene (TOL), in order to explore various possible quenching mechanisms. The experimental results show a positive deviation in Stern Volmer plots for all solvents. Various parameters for the quenching process are determined by ground state complex, sphere of action static quenching model and finite sink approximation model. The magnitudes of these rate parameters indicate that positive deviation in the Stern Volmer (SV) plot is due to both static and dynamic processes. Further, finite sink approximation model is used to check whether these bimolecular reactions were diffusion limited or not. The values of distance parameter R' and diffusion co efficient D are determined and then compared with the values of encounter distance R and diffusion coefficient D calculated using Stokes-Einstein equation.
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Affiliation(s)
- D Nagaraja
- Department of Physics, Bangalore Institute of Technology, Bangalore 560004, Karnataka, India
| | - R M Melavanki
- Department of Physics, MS Ramaiah Institute of Technology, Bangalore 560054, Karnataka, India.
| | - N R Patil
- Department of Physics, BVB College of Engineering and Technology, Hubli 580031, Karnataka, India
| | - R A Kusanur
- Department of Chemistry, R.V. College of Engineering, Bangalore 560059, Karnataka, India
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Nagaraja D, Melavanki RM, Patil NR, Geethanjali HS, Kusanur RA. Solvent effect on the relative quantum yield and fluorescence quenching of a newly synthesized coumarin derivative. LUMINESCENCE 2014; 30:495-502. [DOI: 10.1002/bio.2766] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 08/11/2014] [Accepted: 08/11/2014] [Indexed: 11/08/2022]
Affiliation(s)
- D. Nagaraja
- Department of PhysicsBangalore Institute of Technology Bangalore 560004 Karnataka India
| | - R. M. Melavanki
- Department of PhysicsM S Ramaiah Institute of Technology Bangalore 560054 Karnataka India
| | - N. R. Patil
- Department of PhysicsB V B College of Engineering and Technology Hubli 580031 Karnataka India
| | - H. S. Geethanjali
- Department of PhysicsBangalore Institute of Technology Bangalore 560004 Karnataka India
| | - R. A. Kusanur
- Department of ChemistryR. V. College of Engineering Bangalore 560059 Karnataka India
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Deepa HR, Thipperudrappa J, Suresh Kumar HM. Effect of solvents on the spectroscopic properties of LD-489 & LD-473: estimation of ground and excited state dipole moments by solvatochromic shift method. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 108:288-294. [PMID: 23501941 DOI: 10.1016/j.saa.2013.01.084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 01/04/2013] [Accepted: 01/23/2013] [Indexed: 06/01/2023]
Abstract
The absorption and fluorescence spectra of 6,7,8,9-tetrahydro-6,8,9-trimethyl-4-(trifluoro methyl)-2H-pyrano[2,3-b][1,8]naphthyridin-2-one (LD-489) and 1,2,3,8-tetrahydro-1,2,3,3,8-pentamethyl-5-(trifluoromethyl)-7H-pyrrolo[3,2-g]quinolin-7-one (LD-473) have been recorded at room temperature in different solvents and 1,4-dioxane-acetonitrile solvent mixtures. The UV-Visible absorption spectra are less sensitive to solvent polarity than the corresponding fluorescence spectra in both the dyes which show pronounced solvatochromic effect. The effects of solvents upon the spectral properties are analyzed using Lippert-Mataga polarity function, Richardts microscopic solvent polarity parameter and Catalán's multiple linear regression approach. Both general solute-solvent interactions and specific interactions are operative in these systems. The solvatochromic correlations are used to estimate excited state dipole moments using experimentally determined ground state dipole moments. The excited state dipole moment for both the dyes are found to be larger than their corresponding ground state dipole moment and is interpreted based on their resonance structures.
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Affiliation(s)
- H R Deepa
- Department of Physics, B.N.M. Institute of Technology, Bangalore 560 070, India
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Solvatochromic shift studies in LD-425 and LD-423: Estimation of ground and excited state dipole moments. J Mol Liq 2013. [DOI: 10.1016/j.molliq.2013.02.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Synthesis and spectroscopy of novel branched fluorescent dyes containing benzophenone parts and the possibility as fluorescence probes. J Fluoresc 2010; 21:149-59. [PMID: 20585975 DOI: 10.1007/s10895-010-0699-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 06/22/2010] [Indexed: 10/19/2022]
Abstract
This paper describes a new fluorescent family of branched dyes containing benzophenone unit including 4-N, N-diphenylamino-4'-phenacyl-stilbene (C1), 4,4'-di(4-benzoylphenylethylene)yl-triphenylamine (C2) and 4,4',4″-tri(4-benzoylphenylethylene)yl-triphenylamine (C3). Benzophenone part is coupled with core through C-C double bond. The chemical structures of the derivatives are characterized with (1)H and (13)C nuclear magnetic resonance and elemental analysis. Strong π-π stacking interactions are discovered with the analysis of the X-ray crystallographic data of C1. The absorption maxima and emission maxima of the derivatives exhibit gradual bathochromic shift from C1 to C3. The optical density of C1, C2 and C3 are shown to be related to the number of branches. The changes of dipole moments between the excited and ground states for C1, C2 and C3 were estimated to be 4.356, 8.091 and 8.479 Derby, respectively by Lippert equation, confirming that the internal charge transfer (ICT) dominates the process of excited singlet state. The possibility as fluorescence probes of the derivatives on the estimation of what region of micelles interacting with samples was evaluated.
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