Substituent and solvent effects on UV‐visible absorption spectra of liquid crystalline disubstituted biphenylcyclohexane derivatives – a computational approach

Praveen, P. Lakshmi; Ojha, Durga P.

doi:10.1002/crat.201100481

Cited by 22 publications

(7 citation statements)

References 34 publications

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“…The resistance of a molecule to exchange electron density with the environment is defined as the chemical hardness and when the finite difference approximation is applied, the following simple expression is obtained: (5) With the substitution of I by E HOMO and A by E LUMO can be expressed as: (6) Also the chemical hardness, chemical potential of the molecule was found to be increased, the chemical softness of the molecule was found to be decreased as the dielectric constants of the solvents increased from gas phase to water and was confirmed to decrease as the dielectric constant of the solvents increased from ethanol to water.…”

Section: Resultsmentioning

confidence: 99%

“…So, Iopamidol commonly used for CT, may be also considered as a contrast agent for Magnetic resonance imaging (MRI) applications. 4 The geometry, dipole moment, polarizability, hyperpolarizability, and other molecular properties can be affected by the polarity of the solvent due to variable interactions with the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO) 6,7 and so the polarity of the solvent can influence the stability and reactivity of the molecule. 8 They can be obtained by quantum chemical calculation without laboratory measurements, thus saving time and equipment, reducing safety and disposal concerns.…”

Section: Introductionmentioning

confidence: 99%

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Theoretical B3LYP Study on Electronic Structure of Contrast Agent Iopamidol

Genç

Kandemirli²,

Kandemi̇rlı

2021

ACSi

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Nonionic low-osmolar contrast agents are thought about safe for intravenous or intra-arterial administration. Iopamidol is one of the contrast agents used for diagnostic clinical computed tomography (CT) protocols last four decades years. The molecular structure of Iopamidol was calculated by the B3LYP density functional model with the LANL2DZ basis set by the Gaussian program. The natural bond orbital analysis in terms of the hybridization of atoms and the electronic structure of the title molecule have been analyzed by using the data obtained from the quantum chemical results. First-order hyperpolarizability (βtot), the dipole moment (μ) and polarizability (α) and anisotropic polarizability (Δα) of the molecule have been reported. HOMO and LUMO energies and parameters related to energies, and dipole moment, polarizability and hyperpolarizability show minor dependences on the solvent polarity. The hardness of Iopamidol decreases with increasing solvent polarity. The stability of the Iopamidol contrast agent with the hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital analysis. In addition, thermodynamic properties were obtained in the range of 200–1000 K.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Theoretical B3LYP Study on Electronic Structure of Contrast Agent Iopamidol

Genç

Kandemirli²,

Kandemi̇rlı

2021

ACSi

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show abstract

“…The electronic structures, excitation energies, and excited state wavefunctions have been calculated coupled with the configuration interaction (CI) single level of approximation including all p/p * single excitations. This has been found an adequate to determine the UVevisible absorption spectra [31,32] provided that suitable parameterizations are used. In practice, it requires a comparison of different approximations to gain higher level understanding.…”

Section: Computational Methodologymentioning

confidence: 99%

Calculation of spectral shifts in UV–visible region and photoresponsive behaviour of fluorinated liquid crystals: Effect of solvent and substituent

Praveen¹,

Ojha²

2012

Materials Chemistry and Physics

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“…Recently, we have reported [12,13] the physical behaviour of nematic liquid crystals in benzene (i.e. non-interacting, non-mesogenic and non-polar solvent) -as has Kundu et al [14].…”

Section: Introductionmentioning

confidence: 92%

Semi-empirical analysis on electronic spectra and ultraviolet stability of nematic liquid crystals: effect of solvent and substituent

Praveen¹,

Ojha²

2011

Liquid Crystals

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To cite this article: P. Lakshmi Praveen & Durga P. Ojha (2011) Semi-empirical analysis on electronic spectra and ultraviolet stability of nematic liquid crystals: effect of solvent and substituent, Liquid Crystals, 38:8, 963-970, A semi-empirical analysis has been carried out on two nematic liquid crystals, 4-cyanophenyl-4 -n-pentylbenzoate (CPPB) and 4-cyanophenyl-4 -n-pentoxybenzoate (CPPOB), using the CNDO/S + CI and INDO/S + CI methods. These methods have been applied to simulate and analyse the electronic structures, spectra and ultraviolet (UV) stability of the systems. Phase stability of the systems has also been studied based on molecular charge distribution. The electronic transitions, absorption wavelength, HOMO and LUMO energies are calculated. Furthermore, UV stability of the molecules is discussed in the light of absorption wavelength and electronic transition oscillator strength (f ). The effect of solvent and substituent on these factors is discussed. A comparison among different solvents is also made. These absorption spectra will provide a valuable database for further computational analysis and the other experimental investigations. IntroductionLiquid crystals represent a class of complex fluids that has opened many doors for us to learn a great deal about molecular interactions [1], phase behaviour, transitions and the art of soft condensed matter. These molecular fluids show specific optical properties due to the anisotropy of molecular organisation [2]. This anisotropy plays an important role in applications of the electrical effect, display devices, spatial modulators, etc. The bulk order in these materials has profound control on the way light [3] and electricity behave in the material. A unique insight into this behaviour provides not only information about the particular material under consideration, but also about the global properties of anisotropic fluids and their relationships to other chemical structures and/or physical phenomena.Despite their various applications [4][5][6][7], liquid crystals (LCs) belonging to the 4-cyanophenyl-4 -n-alkylbenzoate (CPnB) homologous series and their composites are less studied than those from cyanobiphenyl series. The simulation of electronic spectra by computational chemistry tools is particularly appealing since a large number of methods have been elaborated and employed to calculate the molecular vertical excitation energies, absorption wavelength and oscillator strength of electronic transitions.In view of this, methods based on Time Dependent Density Functional Theory (TDDFT)

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Substituent and solvent effects on UV‐visible absorption spectra of liquid crystalline disubstituted biphenylcyclohexane derivatives – a computational approach

Cited by 22 publications

References 34 publications

Theoretical B3LYP Study on Electronic Structure of Contrast Agent Iopamidol

Theoretical B3LYP Study on Electronic Structure of Contrast Agent Iopamidol

Calculation of spectral shifts in UV–visible region and photoresponsive behaviour of fluorinated liquid crystals: Effect of solvent and substituent

Semi-empirical analysis on electronic spectra and ultraviolet stability of nematic liquid crystals: effect of solvent and substituent

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