A DFT study on functionalization of acrolein on Ni-doped (ZnO)6 nanocluster in dye-sensitized solar cells

In this work, the functionalization of Acrolein on the Nickel-doped Zn6O6 (A-NiZn5O6) nanocluster with different adsorption configurations (C, M1 & M2) as the π conjugated bridging in dye-sensitized solar cells (DSSC) compared with the anchoring group [6,6] - phenyl-C61-butyric acid methyl ester (PCBM) have been investigated through (DFT/TD-DFT)) calculations by Gaussian 09 program. The interaction between the NiZn5O6 and the Acrolein has been explored through three functional groups are = O Carbonyl group (C), -CH Methyl group (M1), and -CH2 Methylene group (M2) of the Acrolein. The nature of the interaction between the Acrolein and NiZn5O6 has been exhaustively studied in terms of energy gap (Eg), global reactivity descriptors, molecular geometries, adsorption energy, the density of states, Mulliken atomic charges, molecular electrostatic potential, and the UV-Vis spectra for each adsorption site. The frontier molecular orbital analysis study indicated that all dyes could give a suitable electron vaccination from the LUMO orbital of A-NiZn5O6 to the HOMO orbital of PCBM. The adsorption process significantly improved the incident photon to the current conversion potency of the A-NiZn5O6. The determination of density functional theory calculations revealed that the C site of A-NiZn5O6 material was faced with a lower chemical hardness and energy gap (Eg) as well as a higher electron accepting power and light harvesting efficiency compared to other sites.

Adsorption of alanine with heteroatom substituted fullerene for solar cell application: A DFT study

C₂₀ is the most important fullerene cage and alanine is the simplest representation of a backbone unit of the protein. The absorption feasibility of alanine molecule in the Si-doped C₂₀ and B-doped C₂₀ fullerenes has been studied based on calculated electronic properties of fullerenes using density functional theory (DFT). In this work, we explore the ability of Si-doped C₂₀, B-doped C₂₀ fullerene to interact with alanine at the DFT-B3LYP/6-31G, RHF level of theory. We find that noticeable structural change takes place in C₂₀ when one of its carbon is substituted with Si or B. The molecular geometry, electronic properties and vibrational analysis have also been performed on the title compounds. The NMR study reveals the aromaticity of the pure and doped fullerene compounds. Stability of the doped fullerene - alanine compound arises from hyper conjugative interactions. It leads to one of the major property of bioactivity, charge transfer and delocalization of charge and this properties has been analyzed using Natural Bond Orbital (NBO) analysis. The energy gap of the doped fullerene reveals that there is a decrease in the size of energy gap significantly, making them more reactive as compared to C₂₀ fullerene. Theoretical studies of the electronic spectra by using time - dependent density functional theory (TD-DFT) method were helpful to interpret the observed electronic transition state. We aim to optimize the performance of the solar cells by altering the frontier orbital energy gaps. Considering all studied properties, it may be inferred that the applicability of C₂₀ fullerene as the non-linear optical (NLO) material and its NLO property would increase on doping fullerene with Si and B atom. Specifically C₁₉Si would be better among them.

Density functional theory (DFT) investigations on doped fullerene with heteroatom substitution

Structures and stabilities of dodecahedral fullerene C19X (X=Ni, Ti) and C20 have been investigated by quantum chemical calculations based on density functional theory. The geometrical structures, relative stabilities, dielectric constant of the doped cages were studied systematically and compared with those of the fullerene C20 cage. A series of dodecahedral functionalized derivatives have been studied at the B3LYP/6-31G level of density functional theory (DFT). The relative and formation energies of compounds, Mulliken charges, occupancy, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), the HOMO-LUMO band gap and chemical potential (μ) were calculated. The doping effect is discussed in terms of the change in the CC bond length and total dipole moment. The obtained result indicates that the CC bond length increases as a result of doping. The NBO analysis showed that there is a hyper conjugative interaction between the hetero atoms such as titanium and nickel lone-pair electron of doped fullerene with bonding and antibonding (σ(∗)) orbital of carbon atom of fullerene. The stability of the molecule, arising from charge delocalization, has been analyzed using Natural Bond Orbital (NBO) analysis. The nucleus - independent that more negative NICS values in doped fullerene than those of C20. The condensed Fukui Function and the newly introduced the atomic descriptors S (fk) to determine the local reactive sites of the molecular systems during electrophilic, nucleophilic and radical attacks have been calculated for the fullerene C20 compound.

DFT simulations and vibrational analysis of FTIR and FT-Raman spectra of 2-amino-4-methyl benzonitrile

This work deals with the vibrational spectroscopy of 2-amino-4-methyl benzonitrile (AMB) by means of quantum chemical calculations. The mid and far FTIR and FT-Raman spectra were measured in the condensed state. Hartree-Fock (HF/6-31G(*)) and density functional theory (DFT, B3LYP/6-31G(*)) ab initio methods have been performed to interpret the observed vibrational spectra. The vibrational spectra were interpreted with the aid of normal coordinate analysis based on scaled density functional force field. The results of the calculations were applied to simulated infrared and Raman spectra of the title compound, which showed excellent agreement with the observed spectra.

Density functional theory study of Fourier transform infrared and Raman spectra of 2-amino-5-chloro benzonitrile

The vibrational spectra of 2-amino-5-chloro benzonitrile (ACB) have been obtained by density functional theory (DFT) calculations. Normal coordinate analysis has been carried out to support the vibrational analysis. The results were compared with the experimental values. With the help of scaling procedures, the observed FTIR and FT Raman vibrational frequencies were analysed and compared with the theoretically predicted vibrational spectra. The assignments of bands to various normal modes of the molecules were also carried out.

Density functional theory studies on tautomeric stability and infrared and Raman spectra of some purine derivatives

The molecular vibrations of 6-hydroxy-purine (6HP) and 6-amino-purine (6AP) were investigated in polycrystalline sample, at room temperature by Fourier transform infrared (FTIR) and FT-Raman spectroscopy. The spectra of the above compounds have been recorded in the region 4000-50, 3500-100 cm(-1), respectively. They were interpreted with the aid of normal coordinate analysis following full structure optimization and force field calculations based on density functional theory (DFT) using HF/6-31G* and B3LYP/6-311+G** methods and basis set combinations. The results of the calculations were applied to simulated infrared and Raman spectra of the title compounds, which showed excellent agreement with the observed spectra. The dipole moment and the tautometric stability of purine derivatives were also studied.

Analysis of vibrational spectra of 4-amino-2,6-dichloropyridine and 2-chloro-3,5-dinitropyridine based on density functional theory calculations

This work deals with the vibrational spectroscopy of 4-amino-2,6-dichloropyridine (ADCP) and 2-chloro-3,5-dinitropyridine (CDNP) by means of quantum chemical calculations. The mid and far FTIR and FT-Raman spectra were measured in the condensed state. The fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT) with the standard B3LYP/6-31G(*) and B3LYP/6-311+G(**) methods and basis set combinations, and was scaled using various scale factors which yields a good agreement between observed and calculated frequencies. The vibrational spectra were interpreted with the aid of normal coordinate analysis based on scaled density functional force field. The results of the calculations were applied to simulated infrared and Raman spectra of the title compounds, which showed excellent agreement with the observed spectra.