Enlargement of New 3-dimethylaminoanisole (3DMA) Free Essay Example

The present work attention on the design and enlargement of new 3-dimethylaminoanisole (3DMA) derivatives in alternate Donor-Acceptor (D-A) structure for solar cells applications. Six molecules based on 3DMA combined with the electron-rich benzene and triphenylamine units have been investigated using the DFT and TD-DFT methods with B3LYP functional implemented with 6-31+G(d, p) basis set. These results indicate that the extension of pi-conjugation can efficiently improve the absorption intensity. The absorption spectra red-shifts is because the increased ?-spacers significantly destabilize the highest occupied molecular orbital level, whereas the lowest unoccupied molecular orbital level has negligible changed.

This simulation is estimated to assist the design, high – performance dyes for dye-sensitized solar cells applications. This work presents a systematic investigation of the nonlinear optical properties of 3DMA. The FT-IR and FT-Raman spectra of 3-dimethylaminoanisole have been recorded. The vibrational frequencies of the title compound were obtained theoretically by DFT/B3LYP calculations employing the standard 6-31+G(d,p) and cc-pVTZ basis set for optimized geometry and was compared with observed spectrums.

Dye-sensitized solar cells (DSSCs)

Methoxy group, anisole is a hydrogen-bond acceptor molecule, whose aromatic ring is more electron-rich than that in benzene. In such kind of molecules, the role of the substituents is very important. Owing to the symmetry properties and also because of the limited information about the molecular parameters, reliable theoretical calculations for such a molecule is not possible. Therefore, it was thought worthwhile to understand the role of the substituents.

Dye-sensitized solar cells (DSSCs) have concerned substantial attention as prospective low-cost replacements to silicon-based photovoltaic technology [1].

High-performance sensitizers capable of wide-band spectral capture are recognized to be a promising strategy for improving the cost-efficiency of the DSSCs. From this, organic sensitizers are recognized to be ideal for traditionally used sensitizers. The organic dyes have stronger light harvesting efficiency because of their high molar extinction coefficient. The common solar dye-design involves donor connected to an electron acceptor anchoring functionality which allows fine- tuning of optical and electrochemical properties. For donors, benzene and triphenylamines [2, 3], have been successfully used. The electron acceptor anchoring functionality may be chosen as cyanoacrylic acid, nitro and carboxylic acid group functionality are being developed and optimized by several research groups.

Quantum chemical methods have already proven to be very useful in determining the molecular structure and reactivity [4]. Density functional theory (DFT) [5, 6] has provided a very useful framework for developing new criteria for rationalizing, predicting, and eventually understanding many aspects of chemical processes [7-11]. A variety of chemical concepts which are now widely used as descriptors of chemical reactivity, e.g., electronegativity [8] hardness or softness quantities etc., appear naturally within DFT. The Fukui function [10] representing the relative local softness of the electron gas, measures the local electron density population displacements corresponding to the inflow of a single electron.

Due to these applications and the unswerving properties of anisole, a complete vibrational study of 3-Dimetylaminoanisole (3DMA) is undertaken. It has been reported the geometrical structure, quantum chemical calculations, charge distribution among atoms and surfaces, Global reactivity descriptors are also calculated to understand the reactive nature of the compound. Moreover, nonlinear optical, thermodynamical, magnetic properties of 3DMA also studied using B3LYP/ 6-31+G (d, p) and cc-pVTZ basis set. On existent a temperately green solvent, anisole have been effectively pragmatic to process organic/polymer solar cells [12]. From this 3-Dimethylaminoanisole preferably bring in to produce good dye sensitizer.

Experimental and computational details

The sample 3DMA was purchased from the Sigma Aldrich with a purity of greater than 97% and it was used as such without further purification. The Fourier transform infrared (FT-IR) spectrum of the sample was recorded at room temperature in the region 4000-400 cm-1 using Perkin-Elmer spectrum1 spectrophotometer equipped with the composition of the pellet. The Fourier transform Raman (FT-Raman) BRUKER-RFS 27 spectrometer was used for the FT-Raman spectral measurements at room temperature. The sample was packed in a glass tube of about 5 mm diameter and excited in the 180° geometry with 1064 nm laser line at 100 MW power from a diode pumped air cooled-cw Nd:YAG laser as an excitation wavelength in the region 4000-100 cm-1.

Calculations of the title compound were carried out with Gaussian 09W program [13] using the DFT levels of theory using the standard B3LYP/ 6-31+G(d,p) & cc-pVTZ basis sets to predict the molecular structure and vibrational wavenumbers. Molecular geometry (Fig. 1) was fully optimized by optimization algorithm using redundant internal coordinates. The computed wavenumber values contain known systematic errors and hence, we have used the scaling factors 0.9613 and 0.9747 for 6-31+G (d, p) and cc-pVTZ basis sets, respectively [14]. The absence of imaginary wavenumbers of the calculated vibrational spectrum confirms that the structure deduced corresponds to minimum energy. The assignments of the calculated wavenumbers are aided by the animation option of GAUSSVIEW program, which gives a visual presentation of the vibrational modes [15]. The potential energy distribution (PED) is calculated with the help of MOLVIB program version 7.0 written by Sundius [16, 17].

Results and Discussion

The molecular structure of the 3DMA be applicable to C1 point group symmetry. The optimized molecular structure is took from GAUSSIAN 09W and GAUSSVIEW programs as shown in Fig.1 the compound encloses 2-methyl group and amino with anisole. The energy of the 3DMA at B3LYP/6-31+G (d, p) and cc-pVTZ levels are -480.724 and -480.913 Hartees respectively. Table 1 compares the calculated bond lengths and angles for 3DMA with those experimentally available from X-ray diffraction data [18]. From the theoretical values, it is observed that most of the optimized bond lengths are slightly larger than the experimental values, due to that the theoretical calculations belonging to isolated molecules in gaseous phase while the experimental results belong to molecules in solid phase [19]. From the Table 1 we found that in dimethylamino group the hydrogen atom (H10, H17,H15,H21) is in plane with the molecular structure and the other hydrogen atoms namely (H15, H16, H9, H11, H19, H20) are not in plane with the molecular structure. This was proved by the dihedral angle values shown in the Table 1-. The theoretically calculated C-C bond lengths and bond angles are excellent agreement with experimental values. The C-H bond length values in the methyl group are slightly larger than aromatic C-H bond length values.

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