Effect of alkyl chain on the NLO property of nonylphenol isomers: a DFT study

Abstract

Density functional theory (DFT) method was employed to study the nonlinear optical (NLO) response of the nonylphenol isomers with different alkyl substituents (methyl, ethyl, propyl, and isopropyl). The linear alkyl chain (hyperpolarizability, b T ) and alkyl group aggregation (Hyper Rayleigh scattering hyperpolarizability, b HRS ) in nonylphenol isomer has a strong positive influence on the NLO property. Among all the substituents, the methyl dominated alkyl chain nonylphenol isomers are strong NLO materials due to their large polarizability and hyperpolarizability values compared to that of urea/phenol. The absorption spectra obtained from TD-DFT study suggest that the absorption bands are shifted towards the UVVis region, dominated by p-p* transitions. The C-HÁÁÁp intramolecular interactions are a blue shift in nature; however, their function and influence on the NLO property is insignificant. The Rayleigh scattering is dominant for methyl and ethyl substituent, while in the Rayleigh activity is controlled by the natural light. Graphical abstract

Performance of Hybrid DFT Compared to MP2 Methods in Calculating Nonlinear Optical Properties of Divinylpyrene Derivative Molecules

“…According to the calculated values of the static hyperpolarizabilies β 0 , we observe significant variations from one isomer to another. The magnitude of β 0 value increases slightly from the isomer (1,3) to the isomer (1,4), and strongly to isomer (1,5). It acquires its maximum for the isomer (1,6), the difference between the two latter being relatively small.…”

“…Because of their numerous applications in the areas of photonics and optoelectronics, 1−3 various types of NLO active materials have been developed over the recent years. These materials are used in technical applications like lasers, 4 optical data storage devices, biological imaging, 5 signal processing, and in electro-optical modulation as well. 6,7 These materials range from being inorganic to organic to organometallic.…”

“…Because of their numerous applications in the areas of photonics and optoelectronics, − various types of NLO active materials have been developed over the recent years. These materials are used in technical applications like lasers, optical data storage devices, biological imaging, signal processing, and in electro-optical modulation as well. , These materials range from being inorganic to organic to organometallic. − In order to identify additional and more efficient materials for further NLO applications, many studies were conducted on organic materials, including, for instance, the polycyclic aromatic hydrocarbons (PAH) or, polynuclear aromatic hydrocarbons. − These latter are a series of hydrocarbons in which carbon atoms are arranged in multiple aromatic rings sharing one or more C–C bond. The resulting structures are molecules wherein all carbon and hydrogen atoms are lying in the same plane.…”

“…Figure 3. (a) Evolution of first hyperpolarizability β 0 , (b) μ (Debye), (c) ΔE electronic relative energy (kcal/mol), (d) gaps ΔE H-L (eV),(e) E(2)(kcal/mol), and (f) π*/π quotient with respect to the substitution positions(1,3),(1,4),(1,5),(1,6),(1,7),(1,8), and (1,9).…”