Oelschlegel, Manuel; Hua, Shao-An; Schmid, Lucius; Marquetand, Philipp; Baeck, Anna; Borter, Jan-Hendrik; Luecken, Jana; Dechert, Sebastian; Wenger, Oliver S.; Siewert, Inke; Schwarzer, Dirk; Gonzalez, Leticia; Meyer, Franc published the artcile< Luminescent Iridium Complexes with a Sulfurated Bipyridine Ligand: PCET Thermochemistry of the Disulfide Unit and Photophysical Properties>, SDS of cas: 366-18-7, the main research area is crystallog luminescent iridium complex sulfurated bipyridine ligand; PCET thermochem disulfide unit photophys property.
Mol. systems combining light harvesting and charge storage are receiving great attention in the context of, for example, artificial photosynthesis and solar fuel generation. As part of ongoing efforts to develop new concepts for photoinduced proton-coupled electron transfer (PCET) reactivities, we report a cyclometallated iridium(III) complex [1]+ equipped with our previously developed sulfurated bipyridine ligand S-Sbpy. A new one-step synthetic protocol for S-Sbpy is developed, starting from com. available 2,2′-bipyridine, which significantly facilitates the use of this ligand. The iridium complex [Ir(ppy)2(S-Sbpy)](PF6) ([1]PF6) features a two-electron reduction with potential inversion (|E1| > |E2|) at moderate potentials (E1 = -1.17, E2 = -1.08 V vs. Fc+/0 at 253 K), leading to a dithiolate species [1]-. Protonation with weak acids allows for determination of pKa = 23.5 in MeCN for the S-H···S- unit of [1]H. The driving forces for both the H atom and the hydride transfer are calculated to be ∼ 60 kcal mol-1 and verified exptl. by reaction with a suitable H atom and a hydride acceptor, demonstrating the ability of [1]+ to serve as a versatile PCET reagent, albeit with limited thermal stability. In the MeCN solution, an orange emission for [1]PF6 from a triplet-excited state was found. D. functional calculations and ultrafast absorption spectroscopy are used to give insight into the excited-state dynamics of the complex and suggest a significantly stretched S-S bond for the lowest triplet-state T1. The structural responsiveness of the disulfide unit is proposed to open an effective relaxation channel toward the ground state, explaining the unexpectedly short lifetime of [1]+. These insights as well as the quant. ground-state thermochem. data provide valuable information for the use of S-Sbpy-functionalized complexes and their disulfide-/dithiol-directed PCET reactivity.
Inorganic Chemistry published new progress about Attenuated-total-reflectance IR spectroscopy. 366-18-7 belongs to class pyridine-derivatives, and the molecular formula is C10H8N2, SDS of cas: 366-18-7.