The effect of anchoring groups on the electro-optical and charge injection in triphenylamine derivatives@Ti6O12

The triphenylamine (TPA), thiophene and pyrimidine are being used as efficient advanced functional semiconductor materials. In the present study, some new TPA donor–π–acceptor derivatives were designed where TPA moiety acts as donor, thiophene-pyrimidine π-bridge and acetic/cyanoacetic acid as acceptor. The ground-state geometries were optimized at B3LYP/6-31G** level of theory. The excitation energies and oscillator strengths were computed at TD-CAM-B3LYP/6-31G** (polarizable continuum model (PCM), in methanol) level of theory. The electronic, photophysical and charge transport properties were calculated wherever possible the computed values were compared with the available experimental as well as computational data. The electron injection (ΔG inject ), relative electron injection [Formula: see text], electron coupling constants (∣V RP ∣) and light harvesting efficiencies (LHE) have been calculated and compared with referenced compounds. The energies of the lowest unoccupied molecular orbitals (E LUMOs ), diagonal bandgaps and energy level offsets were studied to shed light on the electron transport behavior. The effect of anchoring groups (acetic acid and cyanoacetic acid) was studied on the properties of interests in the dye and dye@ Ti 6 O 12. It was observed that after interaction of dye with the TiO 2 cluster intra-molecular charge transport enhanced from HOMO of the dye to LUMO of the semiconductor cluster. The cyanoacetic acid anchoring group leads the superior LHE, ΔG inject and ∣V RP ∣ which might improve the solar cell performance.

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Exploring the charge injection aptitude in pyrazol and oxazole derivatives by the first-principles approach

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2020-1705 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Ahmad Irfan ◽

Muhammad Imran ◽

Renjith Thomas ◽

Muhammad Asim Raza Basra ◽

Sami Ullah ◽

...

Keyword(s):

Charge Transport ◽

Density Functional ◽

Semiconductor Device ◽

Short Circuit ◽

Short Circuit Current ◽

Electron Injection ◽

Band Alignment ◽

Coupling Constants ◽

Excitation Energies ◽

Biological Potential

Abstract Azole derived products acquired significant consideration in everyday life based on their improved biological potential to the semiconducting substances. The research focused in-depth within pyrazol, and oxazole compounds 1–4 concerning charge transport, structural, optical as well as electronic properties. The density functional theory (DFT) along with time-dependent DFT were used for the optimization of their ground state geometries and excitation energies. We also investigated the molecule’s electron coupling constants (|V RP|) as well as electron injection (ΔG inject) values. For better understanding, charge transport and electronic characteristics were performed through quantum chemical computations. The |V RP| and ΔG inject values of pyrazole, as well as oxazole molecules, exhibited that these compounds could be competent for dye-sensitized solar cell applications. The pyrazole higher diagonal band gap enlightening these might have enhanced fill factor (FF) along with short-circuit current density (J sc ). We have also explored the electron injection, energy level offset, dissociation of excitons, and band alignment of studied compounds to shed light on the functionality of these compounds for photovoltaic and semiconductor device applications.

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Systematic calculations of energy levels and transitions rates in Mo XXVIII

Zeitschrift für Naturforschung A ◽

10.1515/zna-2020-0119 ◽

2020 ◽

Vol 75 (8) ◽

pp. 739-747

Author(s):

Feng Hu ◽

Yan Sun ◽

Maofei Mei

Keyword(s):

Energy Levels ◽

Oscillator Strengths ◽

Atomic Data ◽

Data Sets ◽

Electron Systems ◽

Excitation Energies ◽

Experimental Values ◽

Qed Effects ◽

Hyperfine Structures ◽

Good Agreement

AbstractComplete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Landé gJ-factors and E1, E2, M1, and M2 line strengths, oscillator strengths, transitions rates are reported for the low-lying 41 levels of Mo XXVIII, belonging to the n = 3 states (1s22s22p6)3s23p3, 3s3p4, and 3s23p23d. High-accuracy calculations have been performed as benchmarks in the request for accurate treatments of relativity, electron correlation, and quantum electrodynamic (QED) effects in multi-valence-electron systems. Comparisons are made between the present two data sets, as well as with the experimental results and the experimentally compiled energy values of the National Institute for Standards and Technology wherever available. The calculated values including core-valence correction are found to be in a good agreement with other theoretical and experimental values. The present results are accurate enough for identification and deblending of emission lines involving the n = 3 levels, and are also useful for modeling and diagnosing plasmas.

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Mechanical single-molecule potentiometers with large switching factors from ortho-pentaphenylene foldamers

Nature Communications ◽

10.1038/s41467-020-20311-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jinshi Li ◽

Pingchuan Shen ◽

Shijie Zhen ◽

Chun Tang ◽

Yiling Ye ◽

...

Keyword(s):

Charge Transport ◽

Single Molecule ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Helical Structures ◽

Anchoring Groups ◽

Molecular Conductance ◽

And Control ◽

Helical Molecules ◽

Shed Light

AbstractMolecular potentiometers that can indicate displacement-conductance relationship, and predict and control molecular conductance are of significant importance but rarely developed. Herein, single-molecule potentiometers are designed based on ortho-pentaphenylene. The ortho-pentaphenylene derivatives with anchoring groups adopt multiple folded conformers and undergo conformational interconversion in solutions. Solvent-sensitive multiple conductance originating from different conformers is recorded by scanning tunneling microscopy break junction technique. These pseudo-elastic folded molecules can be stretched and compressed by mechanical force along with a variable conductance by up to two orders of magnitude, providing an impressively higher switching factor (114) than the reported values (ca. 1~25). The multichannel conductance governed by through-space and through-bond conducting pathways is rationalized as the charge transport mechanism for the folded ortho-pentaphenylene derivatives. These findings shed light on exploring robust single-molecule potentiometers based on helical structures, and are conducive to fundamental understanding of charge transport in higher-order helical molecules.

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NMR Properties of the Cyanide Anion, a Quasisymmetric Two-Faced Hydrogen Bonding Acceptor

Symmetry ◽

10.3390/sym13071298 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1298

Author(s):

Ilya G. Shenderovich ◽

Gleb S. Denisov

Keyword(s):

Hydrogen Bonding ◽

Experimental Studies ◽

Polarizable Continuum Model ◽

Coupling Constants ◽

Scalar Coupling ◽

Cyanide Anion ◽

Molecular Systems ◽

Polarizable Continuum ◽

Chemical Shieldings ◽

Nmr Properties

The isotopically enriched cyanide anion, (13C≡15N)−, has a great potential as the NMR probe of non-covalent interactions. However, hydrogen cyanide is highly toxic and can decompose explosively. It is therefore desirable to be able to theoretically estimate any valuable results of certain experiments in advance in order to carry out experimental studies only for the most suitable molecular systems. We report the effect of hydrogen bonding on NMR properties of 15N≡13CH···X and 13C≡15NH···X hydrogen bonding complexes in solution, where X = 19F, 15N, and O=31P, calculated at the ωB97XD/def2tzvp and the polarizable continuum model (PCM) approximations. In many cases, the isotropic 13C and 15N chemical shieldings of the cyanide anion are not the most informative NMR properties of such complexes. Instead, the anisotropy of these chemical shieldings and the values of scalar coupling constants, including those across hydrogen bonds, can be used to characterize the geometry of such complexes in solids and solutions. 1J(15N13C) strongly correlates with the length of the N≡C bond.

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Generalized oscillator strengths and electronic collision cross-sections for nitrogen at excitation energies above 10 eV

Vacuum ◽

10.1016/0042-207x(65)92203-7 ◽

1965 ◽

Vol 15 (9) ◽

pp. 472

Keyword(s):

Cross Sections ◽

Oscillator Strengths ◽

Excitation Energies ◽

Collision Cross Sections ◽

Generalized Oscillator

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Predicting the UV–vis spectra of oxazine dyes

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.7.56 ◽

2011 ◽

Vol 7 ◽

pp. 432-441 ◽

Cited By ~ 36

Author(s):

Scott Fleming ◽

Andrew Mills ◽

Tell Tuttle

Keyword(s):

Excitation Energy ◽

Density Functional ◽

Polarizable Continuum Model ◽

Implicit Solvent ◽

Continuum Approach ◽

Excitation Energies ◽

Functional Theory ◽

Partial Charges ◽

Td Dft ◽

Polarizable Continuum

In the current work we have investigated the ability of time-dependent density functional theory (TD-DFT) to predict the absorption spectra of a series of oxazine dyes and the effect of solvent on the accuracy of these predictions. Based on the results of this study, it is clear that for the series of oxazine dyes an accurate prediction of the excitation energy requires the inclusion of solvent. Implicit solvent included via a polarizable continuum approach was found to be sufficient in reproducing the excitation energies accurately in the majority of cases. Moreover, we found that the SMD solvent model, which is dependent on the full electron density of the solute without partitioning into partial charges, gave more reliable results for our systems relative to the conductor-like polarizable continuum model (CPCM), as implemented in Gaussian 09. In all cases the inclusion of solvent reduces the error in the predicted excitation energy to <0.3 eV and in the majority of cases to <0.1 eV.

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Experimental and Theoretical Studies of 2- (naphthalen-1-yl (piperidin-1-yl) methyl)phenol Compound

Journal of the chemical society of pakistan ◽

10.52568/000694 ◽

2020 ◽

Vol 42 (6) ◽

pp. 818-818

Author(s):

Yeliz Ula Yeliz Ula

Keyword(s):

Molecular Orbital ◽

Theoretical Data ◽

Biologically Active ◽

Oscillator Strengths ◽

Excitation Energies ◽

Petasis Reaction ◽

Vis Spectroscopy ◽

Phenol Compound ◽

Lowest Unoccupied Molecular Orbital ◽

Experimental Values

The 2- (naphthalen-1-yl (piperidin-1-yl) methyl) phenol compound is an alkylaminophenol compound and has been experimentally synthesized by the Petasis reaction. In this study Structural analysis was carried out by FT-IR, NMR, UV-Vis spectroscopy. The high antioxidant value of the compound showed that it could be a potential biologically active drug. Theoretical data support all experimental analysis of the new compound. Comparisons were made by double method. For this purpose, DFT (B3LYP) and HF methods have been used with 6-311G ++ (d, p) set. Also, the compoundand#39;s electronic and structural properties (bond lengths, bond angles and dihedral angles), the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies, electrostatic potential (MEP), vibrational frequencies, Mulliken atomic charges, excitation energies, and oscillator strengths were calculated. As a result; the theoretical and experimental values were found to be compatible.

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Unraveling the Effects of Co-Crystallization on the UV/Vis Absorption Spectra of an N-Salicylideneaniline Derivative. A Computational RI-CC2 Investigation

Molecules ◽

10.3390/molecules25194512 ◽

2020 ◽

Vol 25 (19) ◽

pp. 4512

Author(s):

Jean Quertinmont ◽

Tom Leyssens ◽

Johan Wouters ◽

Benoît Champagne

Keyword(s):

Optical Properties ◽

Crystal Field ◽

Indirect Effects ◽

Density Functional ◽

Crystal Packing ◽

Density Functional Theory Method ◽

Oscillator Strengths ◽

Excitation Energies ◽

Keto Form ◽

Cell Parameters

This work aims at unraveling the effects of co-crystallization on the optical properties of an N-salicylideneaniline-derived molecular switch transforming between an enol and a keto form. This is achieved by way of a two-step multi-scale method where (i) the molecular geometry and unit cell parameters are optimized using a periodic boundary conditions density functional theory method and (ii) the optical properties are computed for a selection of clusters embedded in an array of point-charges that reproduce the crystal field electronic potential. The optical properties (vertical excitation energies and oscillator strengths) are obtained at the RI-CC2/def2-TZVPD level of approximation. This method allows us to decompose the effects of co-crystallization into (i) indirect effects, the geometry changes of the chromophore due to crystal packing with the coformer, and (ii) direct ones, the polarization due to the interacting coformer and to the crystal field. For the former effects, variations of a crucial torsion angle lead to modification of the π-conjugation and therefore to the decrease or increase of the excitation energies. About the latter, they are antagonistic: (i) the coformer is not directly involved in the excitations but its polarization decreases the excitation energies while (ii) the crystal field has the opposite effect. For the co-crystals with succinic and fumaric acids, combining these direct and indirect effects leads to a hypsochromic shift of the first absorption band with respect to the reference crystal, in agreement with experimental data.

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