Investigation of optoelectronic properties of triphenylamine-based dyes featuring heterocyclic anchoring groups for DSSCs’ applications: a theoretical study

This research article published by Springer Nature Switzerland AG., 2020Design and synthesis of new potent sensitizers are of interest for realization of high-efficiency Dye Sensitized Solar Cells (DSSCs). Modification of the triphenylamine-based dyes by introducing suitable anchoring groups aimed at improvement of optoelectronic properties is attempted in our work. The molecular structure, molecular orbitals and energies, electronic absorption spectra, free energies of electron injection and dye regeneration, chemical reactivity parameters and adsorption to TiO2 semiconductor have been reported. Density functional theory (DFT) and time-dependent DFT (TD-DFT) were used to obtain the reported properties. The results reveal superior optical, electronic properties, chemical reactivity parameters and adsorption energies for the investigated dyes. The findings evince that the dyes featuring heterocyclic anchoring groups could be potential candidates for DSSCs’ applications; the new materials are worthy of being investigated experimentally

Theoretical study of the structure and stability of the Na2Cl+, NaCl 2−, Na3Cl 2+, and Na2Cl 3− ions

This research article published by Springer Nature Switzerland AG., 2007The geometrical parameters, normal vibration frequencies, and thermochemical characteristics of the Na2Cl+, NaCl 2−, Na3Cl 2+, and Na2Cl 3− ions in saturated vapors over sodium chloride were calculated by the ab initio methods including electron correlation. According to calculations, the Na2Cl+ and NaCl 2− triatomic ions have a linear equilibrium D ∞h configuration. The pentaatomic ions can exist in the form of the D ∞h linear isomer, C 2v planar cyclic isomer, or D 3h bipyramidal isomer. At ∼1000 K the Na3Cl 2+ and Na2Cl 3− ions exist predominantly in the form of the linear isomers. The energies and enthalpies of the ion-molecule reactions involving the above ions were calculated. The formation enthalpy of the ions Δf H 0(0 K) was determined: 230 ± 2 kJ/mol (Na2Cl+), −96 ± 4 kJ/mol (Na2Cl 3−), −616 ± 2 kJ/mol (NaCl 2−), and −935 ± 4 kJ/mol (Na2Cl 3−)

Structural and thermodynamic characteristics of ionic associates in vapors over sodium bromide and iodide

This research article published by Springer Nature Switzerland AG., 2010Nonempirical methods are used to calculate the geometric parameters, the frequencies of normal vibrations, and thermochemical characteristics of ions existing in saturated vapors over sodium bromide and iodide: Na2X+, NaX 2−, Na3X 2+, and Na2X 3− (X = Br, I). According to the calculations, Na2X+ and NaX 2− triatomic ions have a linear equilibrium configuration of D ∞h symmetry. Pentaatomic ions can exist in the form of three isomers: linear with D ∞h symmetry, planar cyclic with C 2v symmetry, and bipyramidal with D 3h symmetry. At a temperature of ∼1000 K, Na3X 2+ and NaX 3− pentaatomic ions are shown to be present in vapor mainly in the form of linear isomers. The energies and enthalpies of ion molecular reactions with the participation of the above ions are calculated, and the formation enthalpies of the ions are determined, Δ f H o(0 K): 293±2 kJ/mol (Na2Br+), 354±2 kJ/mol (Na2I+), −536±2 kJ/mol (NaBr 2−, −458±2 kJ/mol (NaI 2−, 24±5 kJ/mol (Na3Br 2+, 143±5 kJ/mol (Na3I 2+, −810±5 kJ/mol (Na2Br 3−, and −675±5 kJ/mol (Na2I 3−

Synthesis of a chiral steroid ring D precursor starting from carvone

A chiral five-membered, silyl enol ether containing, steroid ring D precursor has been synthesized front carvone. This silyl enol ether has been applied in the synthesis of a chiral C17 functionalized steroid skeleton using the addition of a carbocation, generated with ZnBr2 from a Torgov reagent, followed by cyclization of the adduct by treatment with acid

Calculation of the Thermodynamic Characteristics of Ions in Vapor over Sodium Fluoride

This research article published Springer Nature Switzerland AG.,2008The geometric parameters, normal vibration frequencies, and thermochemical characteristics of the ions present in vapor over sodium fluoride, Na2F+, Na3F 2+, NaF 2−, and Na2F 3−, were calculated ab initio by the Hartree-Fock method and taking into account electron correlation. The main equilibrium configuration of all ions was found to be the linear configuration of D ∞h symmetry. Pentaatomic ions could also exist as two isomers, planar cyclic of C 2v symmetry and bipyramidal of D 3h symmetry. Their energies were higher than that of the D ∞h isomers, and their contents in vapor were negligibly low. The energies and enthalpies of dissociation of the ions with the elimination of the NaF molecule were calculated. The enthalpies of formation of the ions were obtained

Synthesis of a chiral steroid ring D precursor starting from carvone

A chiral five-membered, silyl enol ether containing, steroid ring D precursor has been synthesized front carvone. This silyl enol ether has been applied in the synthesis of a chiral C17 functionalized steroid skeleton using the addition of a carbocation, generated with ZnBr2 from a Torgov reagent, followed by cyclization of the adduct by treatment with acid

Structure and thermodynamic properties of positive and negative cluster ions in saturated vapour over barium dichloride

This research article published by Taylor &Francis Online, 2013Geometrical structure, vibration spectra, and enthalpies of dissociation have been investigated for the ions BaCl3−, Ba2Cl3+, Ba3Cl5+, and Ba4Cl7+ which were detected earlier in the saturated vapour over BaCl2. Quantum chemical methods of density functional theory, the second and the fourth order Møller–Plesset perturbation theory have been applied. The effective core potential with cc-pVTZ basis set for barium atom and two full-electron basis sets including the diffuse and polarised basis functions for chlorine atom were used. The effect of the basis set size and the computation method on the results was analysed. According to the results, all the ions possess the compact shaped structure. The equilibrium geometrical structures were found as follows: the planar D3h for BaCl3−, triple bridged bipyramidal D3h for Ba2Cl3+, hexabridged D3h for Ba3Cl5+, and septuple bridged C2v for Ba4Cl7+. For positive ions, the different isomeric structures were considered, but no isomers for these ions have been found. The geometrical parameters and vibration frequencies were utilised for computing of thermodynamic functions of the ions, and then the thermodynamic functions were used for the treatment of the experimental mass spectrometric data. The enthalpies of formation ΔfH°(0 K) of the ions were determined (in kJ/mol): −994 ± 6 (BaCl3−), −481 ± 10 (Ba2Cl3+), −1276 ± 14 (Ba3Cl5+), −2048 ± 35 (Ba4Cl7+)