Addressing such challenges requires an in-depth understanding of photokinetic behavior, i.e., the rationalization of how fast light-induced reactions proceed under defined conditions and their associated dependence on experimental parameters. Of particular interest within additive manufacturing are combinations of photoreactions that allow the highly specific selection of dual reaction channels dependent solely on the color of light 13, 14. Narrow near monochromatic or monochromatic emission spectra, combined with a deeper understanding of photoreactivity has led to the design of a plethora of advanced synthetic methods, which take advantage of the properties of the chromophores and their interaction with light of specific wavelengths 7, 8, 9, 10, 11, 12. The opportunity to take advantage of the properties of light sources for improved photochemical outcomes is important in all fields of photochemistry, as was also highlighted in a recent review on photo-catalysis 6. This paradigm change is not only of academic interest for synthetic or biomedical photochemistry and photopharmacology, but has critical connotations for industrial applications 2, 3, 4, 5.
However, the transformation toward using photons as the reagents of the 21st century is in its infancy, with a number of synthetic fields only just starting to reap the benefits of precision photochemistry to its full extent 1. Photochemistry is undergoing a renaissance through adopting tunable lasers and light-emitting diodes as tools to perform light-induced reactions. Importantly, a second algorithm allows the assessment of competing photoreactions and enables the facile design of λ-orthogonal ligation systems based on substituted o-methylbenzaldehydes. The model is validated with experiments at varied wavelengths. Combined with experimental parameters, the data are employed to predict LED-light induced conversion through a wavelength-resolved numerical simulation. A wavelength and concentration dependent reaction quantum yield map of a model photoligation, i.e., the reaction of thioether o-methylbenzaldehydes via o-quinodimethanes with N-ethylmaleimide, is initially determined with a tunable laser system. Herein, we bridge this critical gap by introducing a framework for the quantitative prediction of the time-dependent progress of photoreactions via common LEDs. Photochemical transformations do not currently have the same level of generalized analytical treatment due to the nature of light interaction with a photoreactive substrate. The user will therefore get an indication as to the fact that experimental signals falling within the highlighted area may correspond with the proton directly bonded to the carbon number 9 on the molecule.Predicting the conversion and selectivity of a photochemical experiment is a conceptually different challenge compared to thermally induced reactivity. After having applied this feature, the user will notice that hovering the mouse over an atom will highlight the area on the spectrum corresponding to the simulated value for that atom. The user will be able to select the 'Increments' or the 'Charge' algorithm in the 1H simulation and the 'Neural Network' system (by using NMRPredict Desktop) or the HOSE database methodology (implemented in the server-based NMR Predict application only). The algorithm run for the simulation carried out in the background will be the one selected in the 'Molecule/Prediction Options' menu. The user will be able to use this tool with 1H and 13C NMR spectra just by pasting the corresponding molecular structure (quinine, in this example) over the spectrum and following the menu 'Analysis/Predict & Highlight/Predict ', as shown in the picture below: This tool will be very useful to help the user in the process of assigning 1D NMR spectra. This feature will calculate in the background a simulation of the spectrum of the molecular structure present in the spectral window, highlighting the expected chemical shifts when the user hovers the mouse over a proton or a carbon.