Photoprotective capacities of lichen metabolites: A joint theoretical and experimental study

Optical properties of wine pigments: theoretical guidelines with new methodological perspectives

“…100 nm at λ = 500 nm). *, [45][46]54 As expected, adding a HFlike contribution to the exchange term increased E MAX . In the case of flavonoids, the best agreement was obtained with a moderate HF-like percentage (ca.…”

“…[45][46][47] DFT studies * on anthocyanins have enabled accurate evaluation of conformational, thermodynamic and spectroscopic features (see sections 3.1, 3.2 and 3.3, respectively).…”

“…The latter functional performed particularly well at predicting λ MAX for a large variety of compounds, including systematic variations of the substituent pattern (mainly OH and OCH 3 ), as shown by systematic linear regression when plotting calculated against experimental values with a regression coefficient R 2 of 0.9 ( Figure 2) but a slight deviation from the ideal regression (slope of 0.88 rather than 1). [45][46] Within the wine pigment family, TD-DFT calculations allowed accurate assignment of λ MAX to the S 0 → S 1 transition, with a major contribution of the HOMO → LUMO electronic excitation (commonly > 70%). The entire spectra of flavonoid derivatives are also well reproduced within this method, i.e., energies and peak intensities (related to oscillator strength) over the entire UV/Vis range.…”

Benchmark studies of UV–vis spectra simulation for cinnamates with UV filter profile

“…In particular, density functional theory (DFT) is a quantum mechanical method that can provide an accurate description of the structure, energy and molecular properties of compounds, and, by extending the efficiency of the DFT calculations to excited states, time-dependent density functional theory (TD-DFT) is a powerful and reliable tool when combined with experimental spectral techniques [16][17][18][19][20][21][22][23]. TD-DFT calculations have proved reliable in Table 1 Two-dimensional (2D) structure, international nomenclature of cosmetic ingredients (INCI) and adopted abbreviation of the studied cinnamates providing accurate estimates of the UV-vis absorption spectra of π-conjugated compounds [9,13,15]. Nowadays, studies employing molecular modeling and sunscreen agents are sometimes performed in order to evaluate properties such as environmental photodegradation behavior [24], UV-VIS simulation spectra of natural [9,15,25] and synthetic products [17].…”

Modelagem molecular (TD-DFT) aplicada à simulação de espectros UV para cinamatos com perfil de filtros solares

“…(MILLOT et al, 2012) Foram plotados os gráficos teóricos em relação ao gráfico obtido experimentalmente no intuito de comparar os perfis de absorção. Na Figura 9, podese observar que os funcionais B3LYP e B3P86 resultaram em espectros com os perfis muito parecidos e com pequenas diferenças no valor do λ máx .…”