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1. In‐Situ V _p / V _s Reveals Fault‐Zone Material Variation at the Westernmost Gofar Transform Fault, East Pacific Rise

   https://doi.org/10.1029/2022JB025310  

   Liu, Tianze; Gong, Jianhua; Fan, Wenyuan; Lin, Guoqing (March 2023, Journal of Geophysical Research: Solid Earth)

   Abstract Ocean transform faults often generate characteristic earthquakes that repeatedly rupture the same fault patches. The westernmost Gofar transform fault quasi‐periodically hosts ∼M6 earthquakes every ∼5 years, and microseismicity suggests that the fault is segmented into five distinct zones, including a rupture barrier zone that may have modulated the rupture of adjacentM6 earthquakes. However, the relationship between the systematic slip behavior of the Gofar fault and the fault material properties is still poorly known. Specifically, the role of pore fluids in regulating the slip of the Gofar fault is unclear. Here, we use differential travel times between nearby earthquakes to estimate the in‐situV_p/V_sof the fault‐zone materials. We apply this technique to the dataset collected by an ocean‐bottom‐seismometer network deployed around the Gofar fault in 2008, which recorded abundant microearthquakes, and find a moderateV_p/V_sof 1.75–1.80 in the rupture barrier zone and a lowV_p/V_sof 1.61–1.69 in the down‐dip edge of the 2008M6 rupture zone. This lateral variation inV_p/V_smay be caused by both pore fluids and chemical alteration. We also find a 5%–10% increase inV_p/V_sin the barrier zone during the 9 months before the mainshock. This increase may have been caused by fluid migrations or slip transients in the barrier zone. 

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2. N -[6-(Dimethylamino)-9-phenyl-3 H -telluroxanthen-3-ylidene]- N -methylmethanaminium hexafluorophosphate monoclinic polymorph

   https://doi.org/10.1107/S2414314621005459  

   Myers, Shea; Johnson, Patrick; Benedict, Jason B (June 2021, IUCrData)

   The title compound C₂₃H₂₃N₂Te⁺·PF₆⁻, is a monoclinic polymorph of the previously reported triclinic structure [Calitreeet al.(2007).Organometallics,26, 6248–6257]. In the crystal, parallel offset π–π stacking [shortest centroid–centroid separation = 3.9620 (9) Å] and ionic interactions help to establish the packing. 

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3. Calcium‐Ion Binding Mediates the Reversible Interconversion of Cis and Trans Peroxido Dicopper Cores

   https://doi.org/10.1002/anie.202105421  

   Vargo, Natasha P.; Harland, Jill B.; Musselman, Bradley W.; Lehnert, Nicolai; Ertem, Mehmed Z.; Robinson, Jerome R. (July 2021, Angewandte Chemie International Edition)

   Abstract Coupled dinuclear copper oxygen cores (Cu₂O₂) featured in type III copper proteins (hemocyanin, tyrosinase, catechol oxidase) are vital for O₂transport and substrate oxidation in many organisms.μ‐1,2‐cisperoxido dicopper cores (^CP) have been proposed as key structures in the early stages of O₂binding in these proteins; their reversible isomerization to other Cu₂O₂cores are directly relevant to enzyme function. Despite the relevance of such species to type III copper proteins and the broader interest in the properties and reactivity of bimetallic^CPcores in biological and synthetic systems, the properties and reactivity of^CPCu₂O₂species remain largely unexplored. Herein, we report the reversible interconversion ofμ‐1,2‐transperoxido (^TP) and^CPdicopper cores. Ca^IImediates this process by reversible binding at the Cu₂O₂core, highlighting the unique capability for metal‐ion binding events to stabilize novel reactive fragments and control O₂activation in biomimetic systems. 

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4. Diisobutylammonium triphenyl(2-thiolatoacetato-κ ² O , S )stannate(IV)

   https://doi.org/10.1107/S2414314624007429  

   Song, Xueqing; Yeibyo, Woldegebriel; Li, William; Pike, Robert D (August 2024, IUCrData)

   Crystals of the title salt, (C₈H₂₀N)[Sn(C₆H₅)₃(C₂H₂O₂S)], comprise diisobutylammonium cations and mercaptoacetatotriphenylstannate(IV) anions. The bidentate binding mode of the mercaptoacetate ligand gives rise to a five-coordinated, ionic triphenyltin complex with a distortedcis-trigonal–bipyramidal geometry around the tin atom. In the crystal, charge-assisted ammonium-N—H...O(carboxylate) hydrogen-bonding connects two cations and two anions into a four-ion aggregate. Two positions were resolved for one of the phenyl rings with the major component having a site occupancy factor of 0.60 (3). 

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5. Nonlinear photocarrier dynamics in multilayer W S e ₂ induced by intense terahertz pulses

   https://doi.org/10.1364/JOSAB.504204  

   Guay, Viela; Johnson, Nathan; Zhang, Yue; van_der_Zande, Arend_M; Thorp, Spencer_G; Graham, Matthew; Lee, Yun-Shik (November 2023, Journal of the Optical Society of America B)

   Non-equilibrium photocarriers in multilayer WSe₂injected by femtosecond laser pulses exhibit extraordinary nonlinear dynamics in the presence of intense THz fields. The THz absorption in optically excited WSe₂rises rapidly in the low THz field regime and gradually ramps up at high intensities. The strong THz pulses drive the photocarriers into sidebands of higher mobility and release trapped charge carriers, which consequently enhance the transient conductivity of WSe₂. The spectrally analyzed conductivity reveals distinctive features, indicating that the photocarriers undergo resonant interactions such as carrier-photon scattering. 

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