Electronic structure, cationic, and excited states of nitrogen-containing spiroborates.

Context: This paper presents the results of the study of the electronic structure and cationic and excited states of three spiroborate complexes (2-acetylacetonato-1,3,2-benzodioxaborol, its NH- and NMe-derivatives) and three corresponding ligands (acetylacetone, 4-aminopent-3-en-2-one, and 4-methylaminopent-3-en-2-one). Materials based on spiroborates are used in medicine, for example, as a drug carrier. In industry, spiroborate anions are used in ionic liquids and as alternative high performance lubricants.

XPS and quantum chemical analysis of 4Me-BODIPY derivatives.

The results of a X-ray photoelectron spectroscopy (XPS) and steady-state absorption spectroscopy study of the electronic structure, and cationic and excited states of a series of 1,3,5,7-tetramethyl-substituted BODIPYs (4Me,2R-BODIPYs) are presented. The experimental data were interpreted using high-level quantum chemical computations, including the algebraic diagrammatic construction method for the polarization propagator of the second order (ADC(2)), the outer-valence Green's function (OVGF) method, the density functional (DFT) approach, and the time-dependent DFT (TD-DFT) approach. Substitution effects on the XPS and absorption spectra were determined for 2,6-positions of 4Me,2R-BODIPY pyrrole nuclei (R = H, Br, Bu, benzyl).

Optical properties and electronic structure of Eu(III) complexes with HMPA and TPPO.

Two adducts of Eu(III) tris-hexofluoroacetylacetonate with HMPA (OP(N(CH)), hexamethylphosphotriamide) and TPPO (OP(CH), triphenylphosphine oxide) were studied by optical spectroscopy and quantum chemistry (DFT/TD-DFT). The structure of the higher occupied molecular orbitals (MO) of the two adducts determines differences in the position of the excitation band maximum of hfac ligands. According to the calculation data, all excited states are caused by the transition to 3 vacant π* MOs of hfac ligands.

Photoelectron spectra and electronic structure of boron diacetate formazanates.

The electronic structure and cationic states of two 1,5-diphenylformazanes and two boron diacetate (B(OAc)) formazanates were modeled using the outer valence Green's function (OVGF) and density functional theory (DFT) methods. Comparison of data of the OVGF and ultraviolet photoelectron spectroscopy (UPS) methods made it possible to determine an effect of functional groups and complexing agents on energies of cationic states. Addition of NO-group at the γ-position of the chelate cycle causes stabilization of levels the five upper occupied molecular orbitals (MO) and destabilization of the bonding orbital π + π level.

Halide Perovskite-Derived Compounds RbTeX (X = Cl, Br, and I): Electronic Structure of the Ground and First Excited States.

Herein, we report a study of the electronic structure of the ground and first excited states of RbTeCl, RbTeBr, and RbTeI halide-perovskite-derived crystals. Using X-ray photoelectron spectroscopy (XPS) measurements and density functional theory and multiconfiguration self-consistent field (MCSCF) calculations, the experimental and theoretical XPS spectra of the valence region were obtained. In addition, the effects of the cations and halogen atoms on the electronic structure were determined, and the classification of the excited states in double point group representation was carried out.

Theoretical insights into UV-Vis absorption spectra of difluoroboron β-diketonates with an extended π system: An analysis based on DFT and TD-DFT calculations.

The UV-Vis absorption spectra of difluoroboron β-diketonates with aromatic substituents at the β-carbon are studied thoroughly using DFT and TD-DFT with the CAM-B3LYP functional. The complicated experimental spectra of these dyes can be correctly interpreted by considering their structural features. A closer look at the calculated data shows that the conformational flexibility of these compounds markedly influences their spectral shape.

Spectroscopic and quantum chemical study of difluoroboron β-diketonate luminophores: Isomeric acetylnaphtholate chelates.

The electronic structure and optical properties of the isomeric difluoroboron β-diketonates, 2,2-difluoro-4-methylnaphtho-[2,1-e]-1,3,2-dioxaborin (I) and 2,2-difluoro-4-methylnaphtho-[1,2-e]-1,3,2-dioxaborin (II), were studied by means of X-ray photoelectron, absorption and luminescence spectroscopies. The experimental results were interpreted using high-level ab initio quantum chemical computations, including the algebraic-diagrammatic construction method for the polarization propagator of the second and third orders (ADC(2) and ADC(3)), the outer-valence Green's function (OVGF) method, and the time-dependent density functional (TDDFT) approach. The X-ray photoelectron measurements were assigned in the entire energy range using the results of the Kohn-Sham orbital calculations which employed the B3LYP functional.

Electronic structure and optical properties of Ln(III) nitrate adducts with 1,10-phenanthroline.

Adducts of tris-nitrates of rare-earth elements Ce(III), Nd(III), Eu(III), and Er(III) with two molecules of 1,10-phenanthroline with formula Ln(NO)(Phen) are studied by X-ray photoelectron spectroscopy (XPS) and quantum chemistry (DFT/TDDFT). The geometric structure for DFT modeling is build using X-ray diffraction data. To analyze the composition and differences of the electronic structure in the series under study, XPS spectra were obtained for which interpretation was performed using calculated data.

Correction: Ab initio calculation of energy levels of trivalent lanthanide ions.

Correction for 'Ab initio calculation of energy levels of trivalent lanthanide ions' by Alexandra Ya. Freidzon et al., Phys.

Ab initio calculation of energy levels of trivalent lanthanide ions.

The energy levels of Ln3+ ions are known to be only slightly dependent on the ion environment. This allows one to predict the spectra of f-f transitions in Ln3+ complexes using group theory and simple semiempirical models: Russell-Saunders scheme for spin-orbit coupling, ligand-field theory for the splitting of the electronic levels, and Judd-Ofelt parameterization for reproducing the intensity of f-f transitions. Nevertheless, a fully ab initio computational scheme employing no empirical parameterization and suitable for any asymmetrical environment of Ln3+ would be instructive.

Boron difluoride dibenzoylmethane derivatives: Electronic structure and luminescence.

Electronic structure and optical properties of boron difluoride dibenzoylmethanate and four of its derivatives have been studied by X-ray photoelectron spectroscopy, absorption and luminescence spectroscopy and quantum chemistry (DFT, TDDFT). The relative quantum luminescence yields have been revealed to correlate with charge transfers of HOMO-LUMO transitions, energy barriers of aromatic substituents rotation and the lifetime of excited states in the investigated complexes. The bathochromic shift of intensive bands in the optical spectra has been observed to occur when the functional groups are introduced into p-positions of phenyl cycles due to destabilizing HOMO levels.

Electronic Structure and Optical Properties of Boron Difluoride Dibenzoylmethane Derivatives.

Electronic structure and optical properties of boron difluoride dibenzoylmethanate BF2Dbm and its four derivatives were studied using X-ray photoelectron spectroscopy, absorption and luminescence spectroscopy, and quantum chemistry (DFT and TDDFT). In a series of the studied compounds, the relationship of molecular design and optical properties has been revealed. At the transition from BF2Dbm to BF2Dbm(OCH3)2, the HOMO-LUMO energy gap decreases, resulting in a bathochromic shift of the optical spectra.

Luminescence of solvate of boron difluoride dibenzoylmethanate with benzene: aggregates formation.

The concentration dependence of spectral-luminescence properties of solutions boron difluoride dibenzoylmethanate (DBMBF2) in benzene and chloroform has been studied through stationary and time-resolved emission spectroscopy methods. The formation of J-aggregates in the solution of DBMBF2 in chloroform has been revealed and a crystalline adduct of DBMBF2 with benzene has been obtained. A bright blue adduct luminescence is due only to the luminescence of J-aggregates, unlike the crystals of DBMBF2, for which the luminescence of excimers and J-aggregates has been observed.