Spectral and non-linear optical properties of cyanine bases' derivatives of benzo[c,d]indole (original) (raw)
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Non-Linear Optical Properties Study of Two Heterocyclic Compounds
International Journal of pharma and Bio Sciences
In an attempt towards understanding the relation between molecular structure-nonlinear optic activity (NLO) among heterocycles, with special reference to the identity, number and position of the heteroatom, semiempirical calculations were carried out. This paper reports the Non-linear optical properties of two heterocyclic compounds namely 3-[2-Oxo-2-(2-oxo-2H-chromen-3-yl)ethylidene]-1,3-dihydro-indol-2-one (3OCEDI) and Quinolin-8-ol (QL). To understand the Non-Linear Optical properties of coumarin dyes we computed dipole moment (μ), electronic polarizability (α), and the mean was first hyperpolarizability (βo) using B3LYP density functional theory method in conjunction with 6-31G(d, p) basis set.All the calculations were carried out in gas phase and in acetonitrile medium. The optimized geometry of both compounds shows a 3D helical structure. The results indicate that given the same number and type of atoms and double bonds in a molecule, linear conjugation excels over cyclic or crossed conjugation in enhancing hyperpolarizabilities and it seems to be far more critical than a chiral centre.
The Journal of Physical Chemistry A, 2009
The electronic structures of a homologous series of indole and benzofuran derivatives, in which the nitrogen or oxygen atom is replaced by group 15 and group 16 heavier heteroatoms, have been investigated by means of various spectroscopic techniques coupled with density functional calculations. It was found that the excitation energies of the group 16 benzoheteroles systematically shift to the red in the order of benzofuran , benzothiophene , benzoselenophene (8), and benzotellurophene . In contrast, the electronic absorption spectra of the group 15 benzoheteroles, 1-phenyl derivatives of indole (1b), phosphindole (2b), arsindole (3b), stibindole (4b), and bismuindole (5b), did not exhibit this type of spectral shift. X-ray analysis and density functional theory (DFT) studies revealed that 2b-5b adopt a bent conformation both in the crystalline and in the solution phases. In contrast, planar structures were calculated for the group 16 heterocycles. Using the observed spectroscopic properties and time-dependent density functional theory (TDDFT) calculations, the electronic absorption spectra of the present heterocycles were assigned. A molecular orbital analysis was performed to rationalize the effect of replacement of the heteroatom on the electronic structures. The observed magnetic circular dichroism (MCD) sign patterns of these heterocycles are interpreted according to Michl's perimeter model.
Nonlinear optical study of p-bromo-benzylidene aniline-substituted
8th Iberoamerican Optics Meeting and 11th Latin American Meeting on Optics, Lasers, and Applications, 2013
Schiff bases in general are important molecules from several aspects. They are compounds with a functional group that contains a carbon-nitrogen double bond with the nitrogen atom connected to an aryl or alkyl group, not hydrogen. Imines are crucial synthetic intermediates, they do have biological role and the salicylidene types may exibit thermocromic or photocromic properties. These latter two are connected to structural features, i.e., to the possibility of proton transfer complex formation. In this work, the Z-Scan technique is used to measure the nonlinear optical properties of p-bromo-benzylidene aniline substituted. All compounds display absorption bands in the range between 250 and 440 nm, being transparent in the near infrared region. Under 405 nm milliseconds excitation, the nonlinear optical process of p-bromo-benzylidene aniline substituted in DMSO solutions is caused by laser heating. The optical nonlinearity is proportional to the value of linear absorption and depends on substituent and his position. Downloaded From: http://proceedings.spiedigitallibrary.org/ on 02/25/2014 Terms of Use: http://spiedl.org/terms Proc. of SPIE Vol. 8785 87853Q-3 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 02/25/2014 Terms of Use: http://spiedl.org/terms
ACS Omega
The nonlinear optical (NLO) properties of meta-nitroaniline (m-NA) are evaluated via Huckel−Agrawal's approximation in a solvent environment. In this context, both the 1 B and the intramolecular charge transfer (ICT) electronic transitions are considered. The benzene ring currents on the clockwise or counterclockwise direction and the corresponding Brillouin zone from 0 to π are also considered. Besides, the Bloch equations were applied to a single cell n = 1 defined on the benzene ring. We have considered that the light beam was directed along the ring benzene bonds of m-NA; this topological hypothesis changed the crystal structure to a linear chain and the calculated optical properties were found near the experimental ones. In addition, the Fermi's golden rule was applied to the crystal state and then the calculated refraction index of m-NA had an error of less than 3% of the experimental one. On the other hand, the molar absorptivity ε of m-NA in acetonitrile for the 1 B and intramolecular ICT transitions was experimentally determined to be 11 981 and 1192 L mol −1 cm −1 , respectively. With this methodology, we found that the change of the charge in the NO 2 group has also a strong influence on the linear and NLO properties. In addition, the dipole transition moments, which are originated from the carbon between the carbons joined to NO 2 and NH 2 , are mainly involved in the NLO properties. Thus, the first hyperpolarizability β z was 1.69 × 10 −30 esu at λ Laser = 1064 nm, 27% of the experimental value. We attribute this difference to the evaluation of the excited dipole moment. If we attribute a separation of charge of 0.1 e in the excited state, the new dipole moment allows for the simulation of the experimental value. Besides, the calculated value of χ (3) for m-NA in a solution of acetonitrile is 2.9 × 10 −13 esu at λ Laser = 1064 nm, 158% of the experimental value. The discrepancy between these values is attributed to the influence of the electronic correlation effects, that is, because of resonance structures of the aromatic ring and the zwitterionic pair of nitro and aniline. Besides, we have also evaluated the second hyperpolarizability γ, the second-order susceptibility χ (2) of m-NA and their values have similar differences to the experimental values. This type of approach is important because it reduces computing time and gives insight into the molecular causes responsible for linear and NLO properties in this type of functional groups, which can be used as building blocks in more complex polymer systems.
Semi-empirical calculations of the nonlinear optical properties of polycyclic aromatic compounds
Chemical Physics, 1994
A systematic study of factors influencing nonlinear optical properties, in particular the second hyperpolarizability ( y) , is conducted for a series of polycyclic aromatic hydrocarbons (PAHs). The HOMO-LUMO gap, polarizability (cu), first hyperpolarizability ( p), and second hyperpolarizability of polycyclic aromatic compounds are computed by using semi-empirical MNDO-FF calculation implemented in the MOPAC package. For linear polyacenes, the linear and nonlinear properties and total resonance energy are found to increase while the HOMO-LUMO gap and resonance energy per electron decrease as the number of six-membered rings increases. For nonlinear PAHs, the chain topology should be taken into account. An empirical formula is given to relate the computed ( y) and (cu ) . 0301-0104/94/S 07.00 0 1994 Elsevier Science B.V. All rights reserved. SSDZ 0301-0104(93)E0387-B
Computational and Theoretical Chemistry, 2011
The nonlinear optical (NLO) properties of a series of anilines and N,N-dimethylanilines are studied with second-order Møller-Plesset perturbation theory (MP2). The effect of solvents on the calculated NLO properties is investigated by considering a wide range of solvent systems within the polarizable continuum model. In order to identify systems with high first-order hyperpolarizability, the effects of four basic variations to the molecules on the calculated NLO properties are studied. The modifications comprise changes to the donor strength (NH 2 to N(CH 3 ) 2 ), changes to the acceptor strength (NO 2 , CN and CHO), variation of additional substituents (H, CH 3 , Br, OCH 3 ), and changes in the conjugation length. It is found that the first-order hyperpolarizability increases when the compounds have N,N-dimethyl as donor, vinyl nitro group as acceptor at the 4-position, and a methoxy group as substituent at the 2-position.
Physical Chemistry Research, 2018
This work investigates the structural and nonlinear optical properties of a D-A type 1-[4-({(E)-[4-(methylsulfanyl)phenyl]methylidene}amino)phenyl]ethanone, MMP in which charge transfer occurs from -SCH3 donor to -COCH3 acceptor group through methylidene backbone; and some of its modeled analogues using quantum chemical calculations with pure BLYP and hybrid B3LYP correlation with high basis sets, 6-31G* and 6-31G* in gas phase in a bid to understand their structure-property relationship. The molecular properties like the FMOs energies, dipole moments (μ), polarizabilities (α), molecular first hyperpolarizabilities (β) were obtained. The results showed that the molecular properties were enhanced upon substitution with different groups. The β value is a measure of second order susceptibility of molecule; MMP has a β value of 2.44 x10-30 esu (B3LYP), 3.75 times of urea (0.65 x10-30 esu) and 2.61 x10-30(BLYP), 4.02 times that of urea. The experimental SHG efficiency of MMP is 4.13 time...
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 2014
FT-IR and the effect of various organic solvents on the UV-vis spectras were compared with X-ray and DFT results. NBO, NPA, Mulliken population method and Fukui function analysis were performed. HOMO, LUMO, local reactivity and chemical reactivity were performed. g r a p h i c a l a b s t r a c t
Revista de Chimie
The quantum mechanical and spectral study of two related compounds, namely, 1-p-nitro-benzoyl-benzo[f]quinolinium methylid (BF1) and its cycloadduction derivative 1-p-nitro-benzoyl-2,3-dicarbomethoxy-pyrrolo-[1,2a]-benzo[f]quinoline (BF2) was carried out. Some electro-optical parameters in ground state were estimated by ab initio method. The solvatochromic behavior of the visible spectrum absorption band of the studied molecules in solvents with different macroscopic electro-optical proprieties was analyzed in order to estimate some microscopic molecular parameters of BF1 and BF2 in the excited state. Thus it was evidenced that, by excitation, the increase of BF1dipole moment and electric polarizability occurred while for BF2 either the increase or the decrease of these two parameters was found. The study is of practical importance for further synthesis of new derived compounds with potential applications in life sciences.