Nature Of Electronic Transitions Research Articles

Exploring the physical properties of PVA/PEG polymeric material upon doping with nano gadolinium oxide

Nano gadolinium oxide doped polyvinyl alcohol/polyethylene glycol blend (PVA/PEG) was prepared by sol–gel and casting methods. Rietveld refinement method was used for structural and microstructural investigation. The X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared (FTIR) techniques were applied to study the formation of nano Gd2O3 doped PVA/PEG-blend. Differential scanning calorimetry technique (DSC) was utilized to investigate the glass transition, the melting and degradation temperatures of undoped and doped PVA/PEG blends. The melting temperature was increased slightly while the degradation temperature was reduced upon doping with nano Gd2O3. The behavior of the absorbance and other different optical parameters were studied in detail using UV-spectrophotometer. A variation in the optical bandgap of the PVA/PEG blend was observed while the values of refractive index and extinction coefficient were enhanced as the amount of Gd2O3 increased in the blend. The influence of nano Gd2O3 doping on the different dispersion parameters was examined using Wemple and DiDomenico approximation model. The nature of electronic transitions of different samples was examined by comparing the optical band gap obtained from Tauc’s relation and dielectric loss parameter.

Platinum(II) Complex of Benzimidazole-Derived N-Heterocyclic Carbene: Synthesis, Characterization, and Photophysical Properties

Platinum(II) complex of benzimidazole-derived N-heterocyclic carbene with formula [PtCl2(DMSO)(bimy)] was successfully synthesized via one pot reaction between 1,3-diisopropyl benzimidazolium (bimy×HBr), Ag2O and [PtCl2(DMSO)] (DMSO = dimethyl sulfoxide). The complex was characterized by means of multinuclear (1H and 13C{1H}) magnetic resonance and single crystal X-ray diffraction (XRD). The UV-Vis absorption spectra of the compound show an absorption shoulder above 300 nm. Under excitation by 285 nm UV lamp, solution of the compound in DCM is highly emissive showing emission maxima at around 410 nm. DFT calculations were also carried out for the complex to gain insight on its electronic structure and the nature of electronic transition involved in the absorption/emission process.

Facile access to furo[2′,3′:4,5]pyrido[3,2,1-jk]carbazol-5-ones as blue emitters: photophysical, electrochemical, thermal and DFT studies

A series of thermally stable (up to ≤339°C) and blue fluorescent furo[2′,3′:4,5]pyrido[3,2,1-jk]carbazol-5-ones (FPCOs) with high quantum yields (Ø ≥ 0.75) are reported. These hybrid scaffolds have been synthesized from a bunch of Morita‐Baylis‐Hillman acetate of nitroalkenes and 4-hydroxy-6H-pyrido[3,2,1-jk]carbazol-6-one (HPCO) promoted by DABCO as an organobase at room temperature. All the new chemical structures were assigned by their spectroscopic techniques such as FT-IR, 1H NMR and 13C NMR, HRMS. The solvatochromic studies of targeted scaffolds exhibited blue shifts in absorption and emission spectra with increasing the polarity of solvents. Interestingly, higher quantum yields were also obtained in case of low polar solvents as well as products containing electron-donating groups. The density functional theory calculations indicated that electron-donating substituents led to the lower HOMO-LUMO gap, resulting in bathochromic shifts in absorption spectra. Moreover, chemical hardness, global softness and chemical potential descriptors of compounds are well-estimated. The nature of electronic transition of synthesized scaffolds was well addressed by TD-DFT calculations. In addition, by using NBO and surface analysis calculations, the most nucleophilic and electrophilic sites of title scaffolds were assigned. Interestingly, the cyclic voltammograms of all the FCPOs were shown only one irreversible reduction peak values (-0.62 V to -0.73 V). Therefore, promising charge carrier properties, good thermal robustness and electrochemical stability would make them potential candidates for electronic devices.

Ground and Excited State Electronic Structures of d8-Squared Planar Platinum(II) and Gold(III) Complexes Bearing Cyclometallated 2,6-Diphenylpyridine and Pyrene-Derived N-Heterocyclic Carbene

Electronic structures of four pyrene-derived N-heterocyclic carbene complexes of platinum(II) and gold(III) bearing cyclometallated 2,6-diphenylpyridine have been investigated theoretically. The structures of all complexes in gas phase have been first optimized. Different functionals and basis sets have been tested to find the best theoretical method. The results show that B3PW91 (LANL2DZ/6-31G*) combination give the best description of the molecules as compared with experimentally determined structural features. Using the calculation data from that best functional and mixed basis set combination, frontier molecular orbitals of the complexes have been examined. To gain understanding on the nature of electronic transitions in the UV-vis absorption spectra of the compounds, TD-DFT calculations have been carried out. A details analysis of the vertical excitation reveals that the nature of all the vertical electronic transitions in the complexes. Notably, the lowest energy transitions are πcb + dPt → $$\pi _{{{\text{cb}}}}^{{\text{*}}}$$ (for Pt1 and Pt2) and πCNC → dAu + $$\pi _{{{\text{CNC}}}}^{{\text{*}}}$$ (for Au1 and Au2) charge transfer in nature. A sharp contrast in lowest energy triplet excited state for d8‑squared planar Au1 and Pt1 has been demonstrated. While no contribution from gold(III) d orbital to the SOMO and SOMO – 1 orbital of Au1, there is significant contribution of platinum(II) dyz orbital in the SOMO – 1 orbital of Pt1, suggesting possible interaction of this singly occupied orbital with radical of π-symmetry substrates.

Non-Monotone Dispersion of Carriers in Size-Quantized Nanostructures with Violated Symmetries

The features of the energy spectrum and the movement of carriers in one-dimensional asymmetric semiconductor nanosystems are considered. Asymmetric structures with an additional dip in the potential profile in the quantum wells allow one to vary the positions of the dimensionally quantized levels. An additional influence of the external magnetic field leads to non-monotonic dispersion and lateral local drift of carriers. Such violations of fundamental symmetry will entail corresponding changes in the nature of electronic transitions. The analysis of the dynamic properties of the electronic system of the nanostructure with the asymmetry of the quantum profile was carried out, depending on the intensity of the external magnetic field.

On the electronic transitions of α-Fe2O3 hematite nanoparticles with different size and morphology: Analysis by simultaneous deconvolution of UV–vis absorption and MCD spectra

Nanostructures of the naturally-existing most stable iron oxide, hematite (α-Fe2O3), gain significant research interest in various recent applications. In this study, we put the main focus on magneto-optical (MO) properties of hematite nanoparticles synthesized by a solvothermal approach, and the effects of size, morphology, and particle aggregation on the magnetic circular dichroism (MCD) and conventional absorption spectra are investigated. Simultaneous deconvolution of UV–vis absorption and MCD spectra allows us to discuss the nature of electronic transitions of various hematite nanoarchitectures on the basis of possible transitions in the 3d5 system, giving enhanced spectral resolution and detailed assignments. Consequently, we find (i) characteristic size- and shape-dependent MCD responses at 450–470 nm; and (ii) the presence of both spin-allowed pair excitation and Laporte-forbidden d–d transition with opposite MCD signs in close energy at around 550 nm.

Photophysical, kinetic and thermodynamic study of one-component Type II thioxanthone acetic acid photoinitiators

In this study, One-Component Type II thioxanthone acetic acid based photoinitiators, as well as the conventional Type II photoinitiator with phenyl acetic acid based co-initiators, have been investigated in terms of their photophysical, kinetic and thermodynamic properties by a series of Density Functional Theory (DFT) calculations. Experimental UV–Vis spectra have been compared with computationally generated UV–Vis spectra via Time-Dependent DFT (TD-DFT) and by taking into consideration the vibrational and dynamic effects (Wigner). Natural transition orbitals have been generated for thioxanthone acetic acid derivatives to understand the physical nature of electronic transitions. Furthermore, kinetic and thermodynamic parameters of radical attack to the monomer of thioxanthone acetic acid based radicals and phenyl acetic acid based co-initiator radicals have been investigated. Comparison of the thermodynamic parameters of the initiating radicals has shown that initiation is more favorable with exocyclic radicals in both cases. Exocyclic radicals of the thioxanthone acetic acid derivatives and phenyl acetic acid derivates have been found to have comparable activation energies for their attack to methyl methacrylate. Furthermore, the spin densities and the radical Fukui functions of the attacking radicals have been nicely correlated with the activation barriers. In this way, a fast and predictive approach for the determination of radical reactivity in photopolymerization reactions has been proposed; this enables the evaluation of the initiation efficiency of the photoinitiators prior to synthesis.

Chiral Functionalization of an Atomically Precise Noble Metal Cluster: Insights into the Origin of Chirality and Photoluminescence.

We probe the origin of photoluminescence of an atomically precise noble metal cluster, Ag24Au1(DMBT)18 (DMBT = 2,4-dimethylbenzenethiolate), and the origin of chirality in its chirally functionalized derivatives, Ag24Au1(R/S-BINAS)x(DMBT)18-2x, with x = 1-7 (R/S-BINAS = R/S-1,1'-[binaphthalene]-2,2'-dithiol), using chiroptical spectroscopic measurements and density functional theory (DFT) calculations. Combination of chiroptical and luminescence spectroscopies to understand the nature of electronic transitions has not been applied to such molecule-like metal clusters. In order to impart chirality to the achiral Ag24Au1(DMBT)18 cluster, the chiral ligand, R/S-BINAS, was incorporated into it. A series of clusters, Ag24Au1(R/S-BINAS)x(DMBT)18-2x, with x = 1-7, were synthesized. We demonstrate that the low-energy electronic transitions undergo an unexpected achiral to chiral and back to achiral transition from pure Ag24Au1(DMBT)18 to Ag24Au1(R/S-BINAS)x(DMBT)18-2x, by increasing the number of BINAS ligands. The UV/vis, luminescence, circular dichroism, and circularly polarized luminescence spectroscopic measurements, in conjunction with DFT calculations, suggest that the photoluminescence in Ag24Au1(DMBT)18 and its chirally functionalized derivatives originates from the transitions involving the whole Ag24Au1S18 framework and not merely from the icosahedral Ag12Au1 core. These results suggest that the chiroptical signatures and photoluminescence in these cluster systems cannot be solely attributed to any one of the structural components, that is, the metal core or the protecting metal-ligand oligomeric units, but rather to their interaction and that the ligand shell plays a crucial role. Our work demonstrates that chiroptical spectroscopic techniques such as circular dichroism and circularly polarized luminescence represent useful tools to understand the nature of electronic transitions in ligand-protected metal clusters and that this approach can be utilized for gaining deeper insights into the structure-property relationships of the electronic transitions of such molecule-like clusters.

Photophysical Studies of a Catechol Based Polyfunctional Dipodal Chelator: Application for Optical Probe for Selective Detection of Fe(III).

A novel catechol based dipodal fluorescent chelator N,N'-bis[3-[(E)-(2,3-dihydroxyphenyl)methyleneamino]propyl]propanediamide(MPC), has been developed and its photophysical behaviour was studied by experimental (UV-VIS and fluorescence) and DFT method. The design of the molecule has been inspired from the naturally occurring siderophore enterobactin, a catechol based chelator with amide linkage, that shows an excellent binding efficiency towards Fe(III). The dipodal molecule (MPC) presented here, carries two catechol pendant binding moieties linked to the malonate central unit through propylene spacers by amide linkage. MPC showed good selectivity for Fe(III) at 10-4M concentration in aqueous medium amongst the biologically and environmentally important metal ions chosen viz., Na(I), K(I), Al(III), Cr(III), Fe(III), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II), by demonstrating a remarkable quenching in the fluorescent emission from 262a.u. to 55a.u. at λmax = 477nm. Also, the pre-organized assembled ligand favored an efficient Fe (III) encapsulation through coordination by imine nitrogen and catecholate oxygen donors. High formation constant (log β = 31.3) for 1:1 metal-ligand complex evaluated by both potentiometric and spectrophotometric methods, established the strong binding efficiency of the ligand for Fe(III) metal ion. The binding stoichiometry in the complex was also confirmed from Stern -Volmer and Hill Plot analysis. Further investigation on the emission behavior of MPC in a completely DMSO system explored its suitability for extensive applications in the areas such as, metallurgy, material science, iron contamination remedial in the materials etc.. DFT studies suggest that the ligand displays a U-shaped geometry with a parallel π-stacking and the hydrogen bond between two arms. The experimental infrared, electronic, fluorescence, 1H nmr, 13C nmr spectra were correlated with the theoretical results. The nature of electronic transitions were identified from the TDDFT calculation. The ligand forms a hexa-coordinated complex with six Fe-O bonds extending an orthorhombic geometry due distortion from a regular octahedron.

Optical Dielectric Loss as a Novel Approach to Specify the Types of Electron Transition: XRD and UV-vis as a Non-Destructive Techniques for Structural and Optical Characterization of PEO Based Nanocomposites.

The structure and optical properties of polyethylene oxide (PEO) doped with tin titanate (SnTiO3) nano-filler were studied by X-ray diffraction (XRD) and UV-Vis spectroscopy as non-destructive techniques. PEO-based composed polymer electrolytes inserted with SnTiO3 nano-particles (NPs) were synthesized through the solution cast technique. The change from crystalline phase to amorphous phase of the host polymer was established by the lowering of the intensity and broadening of the crystalline peaks. The optical constants of PEO/SnTiO3 nano-composite (NC), such as, refractive index (n), optical absorption coefficient (α), dielectric loss (εi), as well as dielectric constant (εr) were determined for pure PEO and PEO/SnTiO3 NC. From these findings, the value of n of PEO altered from 2.13 to 2.47 upon the addition of 4 wt.% SnTiO3NPs. The value of εr also increased from 4.5 to 6.3, with addition of 4 wt.% SnTiO3. The fundamental optical absorption edge of the PEO shifted toward lower photon energy upon the addition of the SnTiO3 NPs, confirming a decrement in the optical band gap energy of PEO. The band gap shifted from 4.78 eV to 4.612 eV for PEO-doped with 4 wt.% SnTiO3. The nature of electronic transitions in the pure and the composite material were studied on the basis of Tauc’s model, while optical εi examination was also carried out to calculate the optical band gap.

Synthesis and Electronic Transitions of the Dye Based on 1-{2-[4-(3-Hydroxy-2-oxo-2H-chromen-4-yl)phenyl]-2-oxoethyl}-4-methylpyridinium Bromide

4-[4-(2-Bromoacetyl)phenyl]-3-hydroxy-2H-chromen-2-one reacted with pyridine and 4-methylpyridine to give the corresponding quaternary pyridinium salts. The condensation of 1-{2-[4-(3-hydroxy-2-oxo-2H-chromen-4-yl)phenyl]-2-oxoethyl}-4-methylpyridinium bromide with 4-(dimethylamino)benzaldehyde afforded a new biscyanine dye whose electronic spectrum showed two absorption maxima originating from interactions of chromophores. The nature of electronic transitions in the dye molecule was analyzed by quantum chemical calculations.

A Comparative Study of Theoretical Methods to Estimate Semiconductor Nanoparticles’ Size

In this paper, we compare four different methods to estimate nanoparticle diameters from optical absorption measurements, using transmission electron microscopy (TEM) images as a reference for the nanoparticle size. Three solutions of colloidal nanoparticles coated with thiophenol with different diameters were synthesized by thiolate decomposition. The nanoparticle sizes were controlled by the addition of a certain volume of a 1% sulphur solution in toluene. TEM measurements showed that the average diameter for each type of these nanoparticles was 2.8 nm, 3.2 nm, and 4.0 nm. The methods studied for the calculation of the nanoparticles diameter were: The Brus model, the hyperbolic band model (HBM), the Henglein model, and the Yu equation. We evaluated the importance of a good knowledge of the nanoparticle bandgap energy, and the nature of electronic transitions in the semiconductor. We studied the effects that small variations in the electron and hole effective mass values produced in the Brus equation and in the HBM model for CdS, PbS, and ZnS nanoparticles. Finally, a comparison was performed between the data provided by these models and the experimental results obtained with TEM images. In conclusion, we observed that the best approximation to the experimental results with TEM images was the Brus equation. However, when the bandgap energy was close to the bulk bandgap energy, the theoretical models did not adjust correctly to the size measured from the TEM images.

Engineering the structural, optical and dielectric properties of ZnSe thin films via aluminum nanosandwiching

In this work, two stacked layers of ZnSe thin films are nanosandwiched with aluminum slabs of variable thickness in the range of 10–100 nm. The films which are studied by the X-ray diffraction and ultra-violet visible light spectroscopy techniques exhibit interesting features presented by extension of the cubic lattice parameter, increase in the grain size and reduction in both of the microstrains and defect density. The Al nanosandwiching successfully engineered the energy band gap through narrowing it from 2.84 to 1.85 eV. In addition, the Al nanosandwiching is observed to form interbands that widens upon increasing the Al layer thickness. It also changed the electronic transition nature from direct allowed to direct forbidden type. Moreover, remarkable enhancement in the light absorbability by 796 times is observed near 1.72 eV for two stacked ZnSe layers nanosandwiched with Al slab of thickness of 100 nm. The dielectric constant is also increased three times and the dielectric tunability vary in the range of 3.0-1.2 eV. The nonlinearity in the dielectric spectra and the engineering of the band gap that become more pronounced in the presence of Al slabs make the ZnSe more attractive for nonlinear optical applications.

Spectral-Luminescent Properties of Some Benzaldehyde Derivatives

Substituted benzaldehydes, which are widespread in nature, exhibit antibacterial, anti-inflammatory, antiviral, and anticarcinogenic activity with low toxicity, which makes them promising in medicine. The results of an experimental and theoretical study of the spectral-luminescent properties of four neutral forms of hydroxy- and methoxy-substituted benzaldehydes are presented. The absorption spectra of the studied compounds in hexane and ethanol were obtained. The spectra of fluorescence and fluorescence excitation of the substances in ethanol solutions were measured. Based on quantum chemical calculations, the orbital nature of electronic transitions, the features of the electron density distribution upon excitation, and changes in the structure of the compound are determined and the rate constants of photophysical processes are estimated. According to calculations, in all the compounds studied, the S1 state is formed by the nπ* transition and the intensity of the long-wavelength bands in these compounds is formed by one or two ππ* transitions. The fluorescence quantum yield is estimated from experimental and theoretical data. The results of analysis and comparison of experimental data with the results of quantum chemical calculations allow a conclusion that the neutral forms of the studied substituted benzaldehydes are not responsible for the fluorescence observed in experiments with ethanol solutions.

Synthesis, crystal structure, spectroscopic investigations, and computational studies of Ni(II) and Pd(II) complexes with asymmetric tetradentate NOON Schiff base ligand

In the present study, an asymmetric tetradentate NOON Schiff base ligand 2,2′-((4-methyl-1,2-phenylene)bis(nitrilomethylylidene))bis(4-chlorophenol) (H2L) was synthesized by condensation of 4-methylphenylenediamine with 5-chlorosalicylaldehyde. The Ni(II) and Pd(II) Schiff base complexes were synthesized from the reaction of Ni(OAc)2·4H2O and Pd(OAc)2 with the Schiff base ligand (H2L) in methanol and acetonitrile, respectively. The ligand and its complexes were characterized by FT-IR, 1H NMR, UV-Vis spectroscopy, and elemental analyses. Moreover, the crystal structure of the ligand and Pd(II) complex has been determined by single-crystal X-ray crystallography. The single-crystal X-ray analysis of PdL complex demonstrated a four-coordinated complex by two nitrogen atoms and two phenolate groups. In addition, DFT and TD-DFT calculations were done using M06-2X and B3LYP levels of theory along with Def2-TZVP and ATZP basis sets for ligand and its complexes. Theoretical IR and nature of electronic transition in TD-TDFT data were analyzed by frequency and NBO-CMO calculations.

Vapour deposited nanocomposite films of perylene bis azo-imides with improved photoresponsiveness by visible light

The paper presents preparation of nanocomposite thin films of three newly synthesized perylene bis azo-imides in polyimide matrix by vapour deposition, results of DFT quantum chemical calculations on the optimized molecular geometry of trans (E) and cis (Z) isomers of the studied dyes as well as photoinduced birefringence measurements to explore potential optical application of these novel materials. Vapour deposited single films of the dyes were studied by reflectance UV-VIS and fluorescence spectroscopy in order to investigate the nature of electron transitions and donor-acceptor interactions between phenylazo fragments and perylene core. The nanocomposite films were prepared through vapour deposition of ODA (4,4′-oxydianiline) and PMDA (pyromellitic dianhydride) as the host polymer matrix and of corresponding perylene bis azo-imide dyes as “guest” at two various concentrations 5 % and 10 % w/w. It was found that nanocomposite films have improved photoresponsivness by applying visible light at λ = 532 nm compared to the single deposited films of dyes. This study shows the applicability of the synthesized dyes embedded in the polyimide matrix as visible-light activated molecular switches.

Спектрально-люминесцентные свойства некоторых производных бензальдегида

Substituted benzaldehydes widely distributed in nature exhibit antibacterial, anti-inflammatory, antiviral, anti-carcinogenic activity with low toxicity, which make their promising in medicine. The results of an experimental and theoretical study of the spectral-luminescent properties of four neutral forms of hydroxy- and methoxy-substituted benzaldehydes are presented. The absorption spectra of the studied compounds were obtained in hexane and ethanol. Measurements of fluorescence spectra and fluorescence excitation of solutions were carried out in ethanol. Based on quantum chemical calculations, the orbital nature of electronic transitions, the features of the electron density distribution upon excitation and changes in the structure of the compound are determined and the rate constants of photophysical processes are estimated. According to calculations, for all compounds studied, the S1 state is formed by the nπ-type transition, and the intensity of the long-wavelength bands in these compounds is formed by one or two ππ-transitions. The fluorescence quantum yield values are estimated from experimental and theoretical data. As a result of the analysis and comparison of experimental data and the results of quantum chemical calculations it was concluded that the neutral forms of the studied substituted benzaldehydes are not responsible for the observed fluorescence in experiments with ethanol solutions.

Manganese (II) complexes of tridentate ligands having NNN donors: Structure, DFT calculations, superoxide dismutase, DNA interaction, nuclease and protease activity studies

A new family of manganese complexes Mn(H–N3L)Cl2 (1), [Mn(H–N3L)2](ClO4)2 (2), Mn(Me–N3L)Cl2 (3) and [Mn(Me–N3L)2](ClO4)2 (4) where H–N3L is 1-phenyl-1-(pyridine-2-ylmethyl)-2-(pyridine-2-ylmethylene)hydrazine and Me–N3L 1-phenyl-2-(1-(pyridin-2-yl)ethylidene)-1-(pyridin-2-ylmethyl)hydrazine, have been synthesized and characterized by various spectroscopic techniques such as ESI-mass, IR, UV-vis etc. X-ray crystal structure of complex 3 contains monomeric penta-coordinated complex having square pyramidal geometry (τ = 0.22). Redox properties were investigated for all the complexes. Theoretical calculations (DFT and TD-DFT) were performed using complexes 1 and 3. Geometrical, structural and electronic parameters demonstrated good agreement with the experimental data. TD-DFT calculations revealed nature of electronic transition in the complexes 1 and 3. This work mainly focuses on a series of manganese complexes to assess their potential activity on reactions performed by enzymes. SOD activities of all the complexes were studied via indirect method using NBT (nitro blue tetrazolium) assay. The interaction of the complexes (1–4) with calf thymus DNA was examined using UV–visible, fluorescence and circular dichroism spectral studies to understand the mode and extent of DNA binding. DNA interaction studies indicated partial intercalation as probable mode of interaction. In addition to this complex 1 exhibited oxidative nuclease as well as protease activities in presence of oxidising agent (H2O2).

Multicoloured Thiophene Based AIEgens: Single Crystal Structure Elucidation, Spectral Behaviour and DFT Studies

AbstractA series of Schiff base thiophene derivatives, D1 to D9, which exhibits a phenomenon of aggregation‐induced emission enhancement (AIEE) have been synthesised and characterized by standard spectroscopic techniques. Multicoloured emission enhancement has been achieved just by introduction of electron donating and withdrawing substituent on the thiophene moiety. Few of the molecules in the series exhibited enhanced fluorescence emission intensity in solvent mixture in comparison with that observed in pure solvent supportive of AIE. Single crystal x‐ray diffraction (SCXRD) studies on selected molecules, D6 and D7 of the series revealed the existence of planar structure and a herringbone type of crystal packing arrangement. In specific, molecules D6 and D7, possesses a larger π‐π stacking distance of around 4.866 Å and 4.636 Å, which curbs all the non‐radiative pathways, in turn leading to AIEE. DFT and TDDFT calculations confirm the structural planarity supportive of SCXRD analysis and the nature of electronic transition correlating well with the experimental results.

Определение природы электронных переходов в комплексах родаминового красителя и кластерах CdS

Определение природы электронных переходов в комплексах родаминового красителя и кластерах CdS