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The CAAC‐stabilized dithiolene (L⁰) zwitterion (1), an unusual redox‐active intramolecular frustrated Lewis pair (FLP), activates the B─H bond of boranes via hydride‐coupled reverse electron transfer processes. The reactions of1with catecholborane in THF give a zwitterionic bis(dithiolene)‐based spiroborate (2), in which one sulphur atom (at the C2 carbon) bonds to the (CH₂)₄OB(O)₂C₆H₄chain due to the catecholborane (CatBH)/S_thioureaLewis pair‐mediated THF ring opening. In addition to2, [CAAC(H)]⁺[(Cat)₂B]⁻, (3), CAAC(H)₂, (4), and [CAAC(H)₃]⁺[(Cat)₂B]⁻, (5), are also isolated from these reactions. In addition to synthetic, structural, and spectroscopic data, a plausible reaction mechanism is proposed. This finding provides compelling experimental evidence of FLP‐mediated B─H activation via net proton transfer. 

Sclerocactus dawsoniae McGlaughlin & Naibauer (Cactaceae), a new species from western Colorado, is described. Sclerocactus dawsoniae is segregated from S. glaucus (K. Schum.) L. D. Benson, differing by having a smaller overall size, fewer spines per areole, an allopatric distribution, and substantial genetic differentiation. 

IntroductionRecent advances in genetic data collection utilizing next-generation DNA sequencing technologies have the potential to greatly aid the taxonomic assessment of species of conservation concern, particularly species that have been difficult to describe using morphology alone. Accurate taxonomic descriptions aided by genetic data are essential to directing limited conservation resources to species most in need.Sclerocactus glaucusis a plant endemic to Western Colorado that is currently listed as Threatened under the Endangered Species Act (ESA). However, in 2023, the U. S. Fish and Wildlife Service proposed de-listingS. glaucusfrom the ESA due to recovery of the species. Previous research had found substantial genetic structure between populations in the northern part of theS. glaucusrange relative to the majority of the species distribution. MethodsIn this study we utilized double-digest Restriction-site Associated DNA sequencing (RAD-seq) in order to better understand the genetic structure ofS. glaucus. ResultsOur results indicate thatS. glaucuscontains two distinct evolutionary lineages that warrant recognition at the level of species, with what was previously described asS. glaucusNorth being recognized asSclerocactus dawsoniae. DiscussionThe newly describedS. dawsoniaehas a limited estimated number of individuals, low levels of nucleotide diversity, a very narrow geographic range, and an uneven geographic distribution with most plants being found in a single management area, all of which supports continued direct conservation of this species. In contrast,S. glaucushas a large estimated minimum population size, a broad geographic range that includes numerous protected areas, and adequate levels of genetic diversity. Without further conservation action, a delisting decision forS. glaucuswill simultaneously remove all Endangered Species Act protections forS. dawsoniae. The current work demonstrates the importance of having robust genetic datasets when planning conservation activities for species of concern. Moving forward, we recommend that government stakeholders prioritize supporting genetic studies of endangered species prior to making any changes to listing decisions. 

Abstract A substantial amount of media comparison research has been conducted in the last decade to investigate whether students learn Science, Technology, Engineering, and Mathematics (STEM) content better in immersive virtual reality (IVR) or more traditional learning environments. However, a thorough review of the design and implementation of conventional and IVR conditions in media comparison studies has not been conducted to examine the extent to which specific affordances of IVR can be pinpointed as the causal factor in enhancing learning. The present review filled this gap in the literature by examining the degree to which conventional and IVR conditions have been controlled on instructional methods and content within the K-12 and higher education STEM literature base. Thirty-eight published journal articles, conference proceedings, and dissertations related to IVR comparison studies in STEM education between the years 2013 and 2022 were coded according to 15 categories. These categories allowed for the extraction of information on the instructional methods and content characteristics of the conventional and IVR conditions to determine the degree of control within each experimental comparison. Results indicated only 26% of all comparisons examined between an IVR and conventional condition were fully controlled on five key control criteria. Moreover, 40% of the comparisons had at least one confound related to instructional method and content. When looking at the outcomes of the studies, it was difficult to gather a clear picture of the benefits or pitfalls of IVR when much of the literature was confounded and/or lacked sufficient information to determine if the conditions were controlled on key variables. Implications and recommendations for future IVR comparison research are discussed. 

Dithiolene-based N-heterocyclic silane demonstrates unusual dual nucleophilic reactivity toward boron halides. 

Abstract The 1 : 2 reaction of the imidazole‐based dithiolate (2) with GeCl₂ • dioxane in THF/TMEDA gives3, a TMEDA‐complexed dithiolene‐based germylene. Compound3is converted to monothiolate‐complexed (5) and N‐heterocyclic carbene‐complexed (7) germanium(II) dithiolene complexes via Lewis base ligand exchange. A bis‐dithiolene‐based germylene (8), involving a 3c–4e S‐Ge‐S bond, has also been synthesized through controlled hydrolysis of7. The bonding nature of3,5, and8was investigated by both experimental and theoretical methods.