Structure of [Ru(bpy)_n(AP)_(6-2n)]²⁺homogeneous complexes: DFT calculation vs. EXAFS

Photo-Induced Pyridine Substitution in cis-[Ru(bpy)2(py)2]Cl2: A Snapshot by Time-Resolved X-ray Solution Scattering

“…This behavior seems to be typical of the EXAFS technique; when several neighbors of the same chemical nature are located at close distances, there is a tendency to allow such distances to converge to a common value. 11,47,50 The higher correlation among parameters occurs for R Ru-N(py) /R Ru-N(bpy) = -0.73. All other correlations are below 0.5 in absolute value.…”

“…The results reported in Table 1 are in good agreement with previous studies performed on similar ruthenium complexes. 11,47 (For more details regarding the most relevant paths contributing to the EXAFS signal, see Supporting Information). 59 The lack of emission in aqueous solution of the complex is due to a low-lying 3 MC (metal-centered) or 3 LF (ligand-field) state, which deactivates the 3 MLCT state and is also responsible for the py dissociation.…”

Determination of the electronic and structural configuration of coordination compounds by synchrotron-radiation techniques

“…However, when the technique is applied to more disordered systems, it can result just in the determination of the first coordination shell [388][389][390][391][392][393][394][395]. [396]. In the Figure are also reported: pre-edge (blue) and post-edge (green) lines (obtained by fitting the experimental data with two polynomial functions in suitable pre-and post-edge energy intervals) required to estimate the edgejump Δμ(E 0 ) for normalization of the raw spectrum; atomic-like background μ 0 (E) (pink solid line), employed in the extraction of the EXAFS oscillations, see part (e).…”

“…Assuming a linear response of the fluorescence detector, μx(E) is proportional to the ratio I f (E)/I 0 (E), from which the sample absorption coefficient is evaluated. Figure 3d reports as an example the Ru K-edge XAS spectrum in transmission mode for the [Ru(bpy) 2 (AP) 2 ] 2+ complex, where AP = 4-amminopyridine (the complex structure is shown in Figure 3c), measured in water solution (10 mM concentration) at the BM29 beamline of the European Synchrotron Radiation Facility (ESRF, Grenoble, France) [396]. XAS spectra are routinely normalized to the edge jump Δμ(E 0 ) (indicated in Figure 3d), to obtain data which are independent from specific experimental conditions such as sample thickness, absorber concentration, or detector/amplifiers settings (see Figure 3d).…”

“…At the Ru K-edge (22.1 keV) the X-ray absorption length in water is larger than 1.5 cm. This allowed Salassa et al [396] to use a sufficiently thick sample holder to obtain in transmission mode and edge jump of (µx = 0.05). The fluorescence signal was also collected simultaneously.…”