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We applied reaction microscopy to elucidate fast non-adiabatic dissociation dynamics of deuterated water molecules after direct photo-double ionization at 61 eV with synchrotron radiation. For the very rare D+ + O+ + D breakup channel, the particle momenta, angular, and energy distributions of electrons and ions, measured in coincidence, reveal distinct electronic dication states and their dissociation pathways via spin–orbit coupling and charge transfer at crossings and seams on the potential energy surfaces. Notably, we could distinguish between direct and fast sequential dissociation scenarios. For the latter case, our measurements reveal the geometry and orientation of the deuterated water molecule with respect to the polarization vector that leads to this rare 3-body molecular breakup channel. Aided by multi-reference configuration-interaction calculations, the dissociation dynamics could be traced on the relevant potential energy surfaces and particularly their crossings and seams. This approach also unraveled the ultrafast time scales governing these processes. 

Continuous centrifugation of the reaction mixture can impact the trajectory of a palladium-catalyzed C–H arylation reaction in which catalytically relevant nanoparticles are formingin situfrom a molecular precatalyst. 

Creation of a super-excited radical water cation results in a long-lived excited oxygen fragment that can act as a destructive carrier and initiate secondary reactions such as breakup of DNA strands – a key radiation damage mechanism. 

We present an investigation of the relaxation dynamics of deuterated water molecules after direct photo-double ionization at 61 eV. We focus on the very rare D+ + O+ + D reaction channel in which the sequential fragmentation mechanisms were found to dominate the dynamics. Aided by theory, the state-selective formation and breakup of the transient OD+(a1Δ, b1Σ+) is traced, and the most likely dissociation path—OD+: a1Δ or b1Σ+ → A 3Π → X 3Σ− → B 3Σ−—involving a combination of spin–orbit and non-adiabatic charge transfer transitions is determined. The multi-step transition probability of this complex transition sequence in the intermediate fragment ion is directly evaluated as a function of the energy of the transient OD+ above its lowest dissociation limit from the measured ratio of the D+ + O+ + D and competing D+ + D+ + O sequential fragmentation channels, which are measured simultaneously. Our coupled-channel time-dependent dynamics calculations reproduce the general trends of these multi-state relative transition rates toward the three-body fragmentation channels. 

Contribution of melting Antarctic Ice Sheets (AIS) to rising sea level remains one of the least quantified inputs to predictive models for the future. To improve these estimates, International Ocean Discovery Program Expedition 374 cored five sites in the Ross Sea, Antarctica, to examine the stability of the AIS to past intervals of global warmth. Site U1523 proved difficult to core because of the presence of gravel lags and indurated intervals; thus, we cored three holes with overlapping stratigraphy at that site to recover a more complete stratigraphic section. Given these challenges, no attempt was made to create a composite depth scale or stratigraphic splice during the expedition. Here we use a combination of physical property data (primarily magnetic susceptibility and natural gamma radiation), X-ray fluorescence core scanning, and visual core description to construct a core composite depth below seafloor (CCSF) depth scale to the base of Hole U1523B. This composite depth scale is discontinuous because of challenging coring conditions and variable core recovery, although there are several intervals of reasonably good stratigraphic continuity between 0 and 26 m CCSF and 82 and 96 m CCSF. We also created a stratigraphic splice from 0 to 93.95 m CCSF, although the splice is only continuous to 15.82 m CCSF. Additionally, we mapped the off-splice interval of Core 374-U1523E-1H to the composite depth scale over several intervals with significant core disturbance by stretching and squeezing to obtain a best fit. Development of the composite depth scale and stratigraphic splice will improve postcruise research results by allowing scientists to compare samples from different holes on the same depth scale.