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10. Experimental and DFT Quantum Chemical Studies on Structural, Vibrational and Molecular Properties of Some Substituted 4-Phenylphenols.

Author

Ravindranath, L., Srishailam, K., and Venkatram Reddy, B.

Subjects
*CHEMICAL shift (Nuclear magnetic resonance), *INTRAMOLECULAR charge transfer, *FRONTIER orbitals, *RAMAN spectroscopy, *INFRARED spectra, *WAVENUMBER
Abstract

Fourier Transform infrared spectra (4000–400 cm−1) and Fourier Transform Raman spectra (4000–50 cm−1) were recorded for 2-chloro-4-phenylphenol (CP); 2-nitro-4-phenylphenol (NP); and 2-amino-4-phenylphenol (AP). 1H and 13C NMR spectra, along with UV-Vis spectra of the three samples were also measured. Quantum chemical calculations, at the level of DFT/B3LYP/6-311++G(d,p) theory were implemented to study their ground state geometry, vibrational wave numbers, infrared and Raman intensities, 1H and 13C NMR spectra, frontier molecular orbital parameters, NLO behavior, NBO properties, thermodynamic quantities, rotational constants and MESP behavior. TD-DFT variant was employed to simulate electronic transitions of these molecules. Observed and calculated vibrational frequencies agreed with an rms error 7.44, 8.98 and 6.97 cm−1, the corresponding RMSD values being 7.09, 9.39 and 6.59 cm−1 for CP, NP and AP, respectively. Experimental chemical shifts concurred, with their theoretical counterparts, with RMSD value, 0.19, 0.29 and 0.56 ppm for 1H NMR; and 6.34, 6.28 and 5.39 ppm for 13C NMR, respectively, in CP, NP and AP. This kind of agreement was also true for absorption maxima (λmax) of their electronic transitions in solution form. Frontier molecular orbitals were found useful to understand origin of electronic transition maxima and chemical reactivity of the three molecules which was supported by NBO analyses. The computations showed that the three molecules were potentially good for developing NLO materials. MESP investigations showed that the most reactive sites are at oxygen atoms in the three molecules. Moreover, we also made an attempt to understand the effect of deactivating (Cl, NO2) and activating (NH2) groups on certain properties of the three molecules. Presence of intra-molecular hydrogen bond was predicted in CP, NP and AP. Structure parameters for CP, NP and AP agree well with their experimental counterparts. Computed and measured frequencies, chemical shifts and electronic transitions agree acceptably. Effect of activating and deactivating groups is studied. CP, NP and AP are potential NLO materials. Intra-molecular charge transfer (ICT) is demonstrated using NBO analysis. [ABSTRACT FROM AUTHOR]

Published
2023
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11. Electronic Spectra (Experimental and Simulated), and DFT Investigation of NLO, FMO, NBO, and MESP Characteristics of Some Biphenylcarboxaldehydes.

Author

Srishailam, K., Ravindranath, L., Venkatram Reddy, B., and Ramana Rao, G.

Subjects
*ELECTRONIC spectra, *FRONTIER orbitals, *INTRAMOLECULAR charge transfer, *NATURAL orbitals
Abstract

Experimental UV–Visible spectral data for biphenyl-4-carboxaldehyde (B4A), biphenyl-3-carboxaldehyde (B3A), and biphenyl-2-carboxaldehyde (B2A) were obtained in the spectral space 200–400 nm in a solution of CDCl3. In order to substantiate the experimental data, theoretical quantum chemical calculations were made using time-dependent DFT (TD-DFT) formalism employing B3LYP functional in combination with 6–311++G(d,p) for the three molecules in CDCl3 solution phase. Certain global reactivity descriptors were evaluated with the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) (FMOs) analysis, with in the frame work of DFT/B3LYP/6–311++G(d,p) method for the three molecules being investigated. The non-linear optical (NLO) material profiles of the three molecules consisting of their static NLO parameters were theoretically investigated to find their utility for NLO applications. Hyperconjugative interactions, as revealed by natural bond orbital (NBO) analysis, helped to explain NLO behavior of the molecules in terms of intramolecular charge transfer (ICT). The reactive sites of B4A, B3A, and B2A molecules were probed by MESP surface analysis. Experimental and simulated electronic absorption maxima agree well for, B4A, B3A, and B2A. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) orbitals are used to understand π→π* UV–Visible transitions in the three molecules. The molecules are highly reactive and stable. B4A and B3A are good for developing NLO materials. Space around oxygen atom of the aldehyde moiety of the molecules is the most favorable site, for electrophilic attack. [ABSTRACT FROM AUTHOR]

Published
2023
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18. Electronic Spectra (Experimental and Simulated), and DFT Investigation of NLO, FMO, NBO, and MESP Characteristics of Some Biphenylcarboxaldehydes

Author

Srishailam, K., Ravindranath, L., Reddy, B. Venkatram, and Rao, G. Ramana

Abstract

Experimental UV–Visible spectral data for biphenyl-4-carboxaldehyde (B4A), biphenyl-3-carboxaldehyde (B3A), and biphenyl-2-carboxaldehyde (B2A) were obtained in the spectral space 200–400 nm in a solution of CDCl3. In order to substantiate the experimental data, theoretical quantum chemical calculations were made using time-dependent DFT (TD-DFT) formalism employing B3LYP functional in combination with 6–311++G(d,p) for the three molecules in CDCl3 solution phase. Certain global reactivity descriptors were evaluated with the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) (FMOs) analysis, with in the frame work of DFT/B3LYP/6–311++G(d,p) method for the three molecules being investigated. The non-linear optical (NLO) material profiles of the three molecules consisting of their static NLO parameters were theoretically investigated to find their utility for NLO applications. Hyperconjugative interactions, as revealed by natural bond orbital (NBO) analysis, helped to explain NLO behavior of the molecules in terms of intramolecular charge transfer (ICT). The reactive sites of B4A, B3A, and B2A molecules were probed by MESP surface analysis. Experimental and simulated electronic absorption maxima agree well for, B4A, B3A, and B2A. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) orbitals are used to understand π→π* UV–Visible transitions in the three molecules. The molecules are highly reactive and stable. B4A and B3A are good for developing NLO materials. Space around oxygen atom of the aldehyde moiety of the molecules is the most favorable site, for electrophilic attack.

Published
2022
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27. SYNTHESIS AND ANTIMICROBIAL EVALUATION OF CERTAIN ARYLAZO IMIDAZOLES

Author

M. Sreedevi Meesaraganda, Spoorthy Yadati Narasimha, Ravindranath L. Krishna Rao, and Raghavendra Guru Prasad Aluru

Subjects
Pharmacology, Gram-negative bacteria, biology, Serial dilution, Chemistry, Gram-positive bacteria, Pharmaceutical Science, Antimicrobial, Bioinformatics, biology.organism_classification, Minimum inhibitory concentration, Proton NMR, Antibacterial activity, Spectral data, Nuclear chemistry
Abstract

Seven novel arylazo imidazoles were synthesized and structures have been elucidated on the basis of elemental analysis, IR and 1H NMR spectral data. Antibacterial activity studies was done against two gram positive bacteria (S. aureus, P.aeruginosa,) and two gram negative bacteria (E.coli and B.subtili), while antifungal activity studies was done against C.albicans and A.nigerz. Minimum inhibitory concentration was found out by Serial dilution method. Antibacterial and antifungal activity studies of the title compounds (IIIa-IIIe) was compared with standards namely Furacin and Flucanazole. All the synthesized arylazo imidazoles have shown significant activity against the tested microbes. The compounds IIIb, IIIc and IIId exhibit relatively higher activity than the standards.

Published
2013

33. Direct and simultaneous spectrophotometric determination of Fe (III) and Ni (II) using salicylaldehyde acetoacetic acid hydrazone – applications

Author

Srilalitha, V., Guru Prasad, A. Raghavendra, Kumar, K. Raman, Seshagiri, V., and Ravindranath, L. K.

Subjects
Revistas, Departamento de Química, Ni(II), Determinación simultánea, Química, Facultad de Ciencias, Zero crossing measurement, Revista Avances en Química, Medición a cruzamiento cero, Spectrophotometry, Simultaneous determination, Fe(III), Applicaciones, Applications, Artículos Científicos [Revista Avances en Química], Espectrofotometría
Abstract

Un método espectrométrico rápido, simple y sensible ha sido desarrollado para la determinación de Fe(III) y Ni(II) usando la hidrazona del ácido saliciladehido acetoacético (SAAH) como reactivo cromofórico. Las curvas de calibración lineal fueron obtenidas en cada caso. El método propuesto es aplicado para la determinación simultánea de Fe(III) y Ni(II) empleando su espectros de primer orden. El método está basado en la medición de cruzamiento cero de las amplitudes de la primera derivada. Las amplitudes de la primera derivada a 525 nm y 395 nm obedecen la ley de Beer en el rango de concentración 0,054-0,270 μg/mL y 0,112-0,561 μg/mL para Fe(III) y Ni(II), respectivamente. Un gran número de iones no interfieren en el presente método. El método es usado para la determinación de cantidades micro de Fe(III) y Ni(II) en mezclas de acero y en mezclas sintéticas. A rapid, simple and sensitive spectrophotometric method has been developed for determination of Fe (III) and Ni (II) using salicylaldehyde acetoacetic acid hydrazone (SAAH) as a chromophoric reagent. The linear calibration ranges were obtained in each case. The proposed method is applied for the simultaneous determination of Fe (III) and Ni (II) utilizing their first order spectra. The method is based on the zero crossing measurement of first derivative amplitudes. The first derivative amplitudes at 525 nm and 395 nm obey Beer's law in the concentration range 0.054-0.270 μg/mL and 0.112-0.561 μg/mL for Fe (III) and Ni (II) respectively. A large number of foreign ions do not interfere in the present method. The method is used for the determination of micro amounts of Fe (III) and Ni (II) in alloy steels and in synthetic mixtures. 153-159 guruprasadar@yahoo.co.in cuatrimestre

Published
2011

40. Erratum: Elevated osteonectin/SPARC expression in primary prostate cancer predicts metastatic progression

Author

DeRosa, C A, primary, Furusato, B, additional, Shaheduzzaman, S, additional, Srikantan, V, additional, Wang, Z, additional, Chen, Y, additional, Siefert, M, additional, Ravindranath, L, additional, Young, D, additional, Nau, M, additional, Dobi, A, additional, Werner, T, additional, McLeod, D G, additional, Vahey, M T, additional, Sesterhenn, I A, additional, Srivastava, S, additional, and Petrovics, G, additional

Published
2011
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41. Elevated osteonectin/SPARC expression in primary prostate cancer predicts metastatic progression

Author

DeRosa, C A, primary, Furusato, B, additional, Shaheduzzaman, S, additional, Srikantan, V, additional, Wang, Z, additional, Chen, Y, additional, Siefert, M, additional, Ravindranath, L, additional, Young, D, additional, Nau, M, additional, Dobi, A, additional, Werner, T, additional, McLeod, D G, additional, Vahey, M T, additional, Sesterhenn, I A, additional, Srivastava, S, additional, and Petrovics, G, additional

Published
2011
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45. Development and validation of a highly sensitive LC-MS/MS method for simultaneous quantitation of nortriptyline and 10-hydroxynortriptyline in human plasma: application to a human pharmacokinetic study

Author

Hotha, Kishore Kumar, primary, Ravindranath, L. K., additional, Veera, K. N. Jaya, additional, Kumar, K. Kishore, additional, Reddy, Y. Ramachandra, additional, Jagadeesh, B., additional, Rao, D. V. Narayana, additional, Bharathi, D. Vijaya, additional, and Mullangi, Ramesh, additional

Published
2010
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50. Transcriptome analyses of benign and malignant prostate epithelial cells in formalin-fixed paraffin-embedded whole-mounted radical prostatectomy specimens

Author

Furusato, B, primary, Shaheduzzaman, S, additional, Petrovics, G, additional, Dobi, A, additional, Seifert, M, additional, Ravindranath, L, additional, Nau, M E, additional, Werner, T, additional, Vahey, M, additional, McLeod, D G, additional, Srivastava, S, additional, and Sesterhenn, I A, additional

Published
2007
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