X‐Ray Transient Absorption Spectroscopy

Excited state electron and energy relays in supramolecular dinuclear complexes revealed by ultrafast optical and X-ray transient absorption spectroscopy

“…In this work we take advantage of the element specificity of X-ray absorption spectroscopy to separate the dynamics of two individual metal sites in a newly synthesized heterodinuclear copper/ruthenium complex through multi-edge X-ray transient absorption spectroscopy (XTA). 101 We then compare these results with those obtained from optical transient absorption (OTA) and a series of electronic structure calculations to unambiguously construct a detailed picture of the evolution of the complex following excitation of the MLCT band. After establishing a model to describe the dynamics of the heterodinuclear system, we then apply these conclusions to the more challenging problem of an asymmetric homodinuclear Cu( i ) complex.…”

Soft X-ray absorption spectroscopy study of (Ba0.5Sr0.5) (Co0.8Fe0.2)1−хNbхO3−δ with different content of Nb (5%–20%)

“…With respect to late transition metal compounds, according to [32] the number of unpaired 3d-electrons reduces in the creation of the core hole, i.e., they do not represent the ground-state spin state for these compounds (but conserves for early transition metal compounds).The dipole selection rules make the spectra strongly depending on the symmetry of the initial state of the Co ions. According to [33,34,35], in a high-spin state the exchange coupling between the core-hole and 3d electrons tends to reduce noticeably the branching ratio from ½, while in the case when the Co ions mainly have the local low-spin state character the branching ratio differs from ½ only slightly. Analysis of the values obtained for studied BSCF with partial Nb substitution allows to conclude that the ratio L2/L3 is 0.4 in all the samples apart from BSCFN10 indicating that the Co ions in these samples mainly have the local low-spin state character (Co 3+ state).…”

Exploring fingerprints of ultrafast structural dynamics in molecular solutions with an X-ray laser

“…8 As a result, the time-energy landscape of chemical reactions has been traditionally in the focus of spectroscopy studies, while scattering is typically used to probe the structure. [9][10][11][12][13][14][15][16][17][18][19][20][21][22] The emergence of ultrabright hard X-ray free-electron laser (XFEL) sources opened exciting possibilities for time-resolved X-ray studies. [23][24][25][26][27][28] The intense and ultrashort X-ray pulses produced by XFELs allow one to access high-resolution structural information from solution scattering at femtosecond and picosecond timescales, [29][30][31][32][33][34][35] as recently reviewed by e.g.…”