1. Ultrafast primary processes of an iron-(III) azido complex in solution induced with 266 nm light.
- Author
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Vennekate H, Schwarzer D, Torres-Alacan J, Krahe O, Filippou AC, Neese F, and Vöhringer P
- Subjects
- Kinetics, Models, Molecular, Molecular Conformation, Solutions, Spectrophotometry, Ultraviolet, Spectroscopy, Fourier Transform Infrared, Azides chemistry, Iron chemistry, Light, Organometallic Compounds chemistry, Photochemical Processes
- Abstract
The ultrafast photo-induced primary processes of the iron-(III) azido complex, [Fe(III)N(3)(cyclam-acetato)] PF(6) (1), in acetonitrile solution at room temperature were studied using femtosecond spectroscopy with ultraviolet (UV) excitation and mid-infrared (MIR) detection. Following the absorption of a 266 nm photon, the complex undergoes an internal conversion back to the electronic doublet ground state at a time scale below 2 ps. Subsequently, the electronic ground state vibrationally cools with a characteristic time constant of 13 ps. A homolytic bond cleavage was also observed by the appearance of ground state azide radicals, which were identified by their asymmetric stretching vibration at 1659 cm(-1). The azide radical recombines in a geminate fashion with the iron containing fragment within 20 ps. The cage escape leading to well separated fragments after homolytic Fe-N bond breakage was found to occur with a quantum yield of 35%. Finally, non-geminate recombination at nanosecond time scales was seen to further reduce the photolytic quantum yield to below 20% at a wavelength of 266 nm., (This journal is © the Owner Societies 2012)
- Published
- 2012
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