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1. Crystal structures of two copper(I)–6,6′-dimethyl-2,2′-bipyridyl (dmbpy) compounds, [Cu(dmbpy) 2 ] 2 [ M F 6 ]· x H 2 O ( M = Zr, Hf; x = 1.134, 0.671)

   https://doi.org/10.1107/S2056989021007295  

   Wang, Yiran ; Nisbet, Matthew L. ; Poeppelmeier, Kenneth R. ( August 2021 , Acta Crystallographica Section E Crystallographic Communications)

   The syntheses and crystal structures of two bimetallic molecular compounds, namely, bis[bis(6,6′-dimethyl-2,2′-bipyridine)copper(I)] hexafluoridozirconate(IV) 1.134-hydrate, [Cu(dmbpy) 2 ] 2 [ZrF 6 ]·1.134H 2 O (dmbpy = 6,6′-dimethyl-2,2′-bipyridyl, C 12 H 12 N 2 ), (I), and bis[bis(6,6′-dimethyl-2,2′-bipyridine)copper(I)] hexafluoridohafnate(IV) 0.671-hydrate, [Cu(dmbpy) 2 ] 2 [HfF 6 ]·0.671H 2 O, (II), are reported. Apart from a slight site occupany difference for the water molecule of crystallization, compounds (I) and (II) are isostructural, featuring isolated tetrahedral cations of copper(I) ions coordinated by two dmbpy ligands and centrosymmetric, octahedral anions of fluorinated early transition metals. The tetrahedral environments of the copper complexes are distorted owing to the steric effects of the dmbpy ligands. The extended structures are built up through Coulombic interactions between cations and anions and π–π stacking interactions between heterochiral Δ- and Λ-[Cu(dmbpy) 2 ] + complexes. A comparison between the title compounds and other [Cu(dmbpy) 2 ] + compounds with monovalent and bivalent anions reveals a significant influence of the cation-to-anion ratio on the resulting crystal packing architectures, providing insights for future crystal design of distorted tetrahedral copper compounds. 

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2. Determination of Fv / Fm from Chlorophyll a Fluorescence without Dark Adaptation by an LSSVM Model

   https://doi.org/10.34133/plantphenomics.0034  

   Xia, Qian ; Tang, Hao ; Fu, Lijiang ; Tan, Jinglu ; Govindjee, Govindjee ; Guo, Ya ( January 2023 , Plant Phenomics)

   Evaluation of photosynthetic quantum yield is important for analyzing the phenotype of plants. Chlorophyll a fluorescence (ChlF) has been widely used to estimate plant photosynthesis and its regulatory mechanisms. The ratio of variable to maximum fluorescence, F v / F m , obtained from a ChlF induction curve, is commonly used to reflect the maximum photochemical quantum yield of photosystem II (PSII), but it is measured after a sample is dark-adapted for a long time, which limits its practical use. In this research, a least-squares support vector machine (LSSVM) model was developed to explore whether F v / F m can be determined from ChlF induction curves measured without dark adaptation. A total of 7,231 samples of 8 different experiments, under diverse conditions, were used to train the LSSVM model. Model evaluation with different samples showed excellent performance in determining F v / F m from ChlF signals without dark adaptation. Computation time for each test sample was less than 4 ms. Further, the prediction performance of test dataset was found to be very desirable: a high correlation coefficient (0.762 to 0.974); a low root mean squared error (0.005 to 0.021); and a residual prediction deviation of 1.254 to 4.933. These results clearly demonstrate that F v / F m , the widely used ChlF induction feature, can be determined from measurements without dark adaptation of samples. This will not only save experiment time but also make F v / F m useful in real-time and field applications. This work provides a high-throughput method to determine the important photosynthetic feature through ChlF for phenotyping plants. 

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3. Synthesis, Characterization, and Electrochemistry of the Homoleptic f Element Ketimide Complexes [Li] 2 [M(N═C t BuPh) 6 ] (M = Ce, Th)

   https://doi.org/10.1021/acs.inorgchem.9b01428  

   Assefa, Mikiyas K. ; Sergentu, Dumitru-Claudiu ; Seaman, Lani A. ; Wu, Guang ; Autschbach, Jochen ; Hayton, Trevor W. ( September 2019 , Inorganic Chemistry)
4. 2D Homologous Series SrFM n BiS n+2 (M = Pb, Ag 0.5 Bi 0.5 ; n = 0, 1) and Commensurately Modulated Sr 2 F 2 Bi 2/3 S 2

   https://doi.org/10.1021/acs.inorgchem.2c00663  

   Chen, Haijie ; McClain, Rebecca ; Shen, Jiahong ; He, Jiangang ; Malliakas, Christos D. ; Spanopoulos, Ioannis ; Zhang, Chi ; Zhao, Chendong ; Wang, Yang ; Li, Qiang ; et al ( May 2022 , Inorganic Chemistry)
5. From antiferromagnetic and hidden order to Pauli paramagnetism in U M 2 Si 2 compounds with 5 f electron duality

   https://doi.org/10.1073/pnas.2005701117  

   Amorese, Andrea ; Sundermann, Martin ; Leedahl, Brett ; Marino, Andrea ; Takegami, Daisuke ; Gretarsson, Hlynur ; Gloskovskii, Andrei ; Schlueter, Christoph ; Haverkort, Maurits W. ; Huang, Yingkai ; et al ( December 2020 , Proceedings of the National Academy of Sciences)

   null (Ed.)

   Using inelastic X-ray scattering beyond the dipole limit and hard X-ray photoelectron spectroscopy we establish the dual nature of the U 5 f electrons in U M 2 S i 2 (M = Pd, Ni, Ru, Fe), regardless of their degree of delocalization. We have observed that the compounds have in common a local atomic-like state that is well described by the U 5 f 2 configuration with the Γ 1 ( 1 ) and Γ 2 quasi-doublet symmetry. The amount of the U 5 f 3 configuration, however, varies considerably across the U M 2 S i 2 series, indicating an increase of U 5f itineracy in going from M = Pd to Ni to Ru and to the Fe compound. The identified electronic states explain the formation of the very large ordered magnetic moments in U P d 2 S i 2 and U N i 2 S i 2 , the availability of orbital degrees of freedom needed for the hidden order in U R u 2 S i 2 to occur, as well as the appearance of Pauli paramagnetism in U F e 2 S i 2 . A unified and systematic picture of the U M 2 S i 2 compounds may now be drawn, thereby providing suggestions for additional experiments to induce hidden order and/or superconductivity in U compounds with the tetragonal body-centered T h C r 2 S i 2 structure. 

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