RESUMEN
Biomimetic models that contain elements of photosynthesis are fundamental in the development of synthetic systems that can use sunlight to produce fuel. The critical task consists of running several rounds of light-induced charge separation, which is required to accumulate enough redox equivalents at the catalytic sites for the target chemistry to occur. Long-lived first charge-separated state and distinct electronic signatures for the sequential charge accumulated species are essential features to be able to track these events on a spectroscopic ground. Herein, we use a double-excitation nanosecond pump-pump-probe experiment to interrogate two successive rounds of photo-induced electron transfer on a molecular dyad containing a naphthalene diimide (NDI) linked to a [Ru(bpy)3 ]2+ (bpy=bipyridine) chromophore by using a reversible electron donor. We report an unprecedented long-lived two-electron charge accumulation (t=200â µs).
RESUMEN
We report on the first successful rovibrational study of gas phase mononitrotoluene and dinitrotoluene in the TeraHertz/Far-Infrared (THz/FIR) spectral domain. Using the AILES beamline of the synchrotron SOLEIL and a Fourier Transform spectrometer connected to multipass cells, the low-energy vibrational cross-sections of the different isomers of mononitrotoluene have been measured and compared to calculated spectra with the density functional theory including the anharmonic contribution. The active FIR modes of 2,4 and 2,6 dinitrotoluene have been assigned to the vibrational bands measured by Fourier Transform FIR spectroscopy of the gas-phase molecular cloud produced in an evaporating/recondensating system. This study highlights the selectivity of gas phase THz/FIR spectroscopy allowing an unambiguous recognition and discrimination of nitro-aromatic compounds used as explosive taggants.