Monitoring of water oxidation by the established Co cubane catalyst Co4O4(OAc)4(py)4 (abbrev. Co4O4, OAc = acetate, py = pyridine) by time-resolved rapid-scan ATR FT-IR spectroscopy revealed the O-O bond forming intermediate by its O-O stretch mode at 833 cm-1. The catalysis was either driven in alkaline solution by a visible light sensitizer or in hydroxide (OH-) containing acetonitrile solution using the one-electron oxidized cubane as the sole source of charge. The μ-peroxido structure of the intermediate was established by 18O isotopic labeling, and its catalytic relevancy and role in the O2 evolving cycle were revealed by the kinetic relationship with decreasing cubium ([Co4O4]+) and recovery of the Co4O4 complex.

We describe PSR J1926-0652, a pulsar recently discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Using sensitive single-pulse detections from FAST and long-term timing observations from the Parkes 64 m radio telescope, we probed phenomena on both long and short timescales. The FAST observations covered a wide frequency range from 270 to 800 MHz, enabling individual pulses to be studied in detail. The pulsar exhibits at least four profile components, short-term nulling lasting from 4 to 450 pulses, complex subpulse drifting behaviors and intermittency on scales of tens of minutes. While the average band spacing P 3 is relatively constant across different bursts and components, significant variations in the separation of adjacent bands are seen, especially near the beginning and end of a burst. Band shapes and slopes are quite variable, especially for the trailing components and for the shorter bursts. We show that for each burst the last detectable pulse prior to emission ceasing has different properties compared to other pulses. These complexities pose challenges for the classic carousel-type models.