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Let n ≥ 3 and let K ⊂ ℝn be a convex body. A point p ∈ int K is said to be a Larman point of K if for every hyperplane Π passing through p, the section Π ∩ K has an (n – 2)-plane of symmetry. If p is a Larman point of K and for every section Π ∩ K, p is in the corresponding (n – 2)-plane of symmetry, then we call p a revolution point of K. We conjecture that if K contains a Larman point which is not a revolution point, then K is either an ellipsoid or a body of revolution. This generalizes a conjecture of Bezdek for n = 3. We prove several results related to the conjecture for strictly convex origin symmetric bodies. Namely, if K ⊂ ℝn is a strictly convex origin symmetric body that contains a revolution point p which is not the origin, then K is a body of revolution. This generalizes the False Axis of Revolution Theorem in [7]. We also show that if p is a Larman point of K ⊂ ℝ3 and there exists a line L such that p ∉ L and, for every plane Π passing through p, the line of symmetry of the section Π ∩ K intersects L, then K is a body of revolution (in some cases, K is a sphere). We obtain a similar result for projections of K. Additionally, for K ⊂ ℝn with n ≥ 4, we show that if every hyperplane section or projection of K is a body of revolution and K has a unique diameter D, then K is a body of revolution with axis D. [ABSTRACT FROM AUTHOR]

The synthetic methodology for the preparation of photoresponsive dioxazaborocanes-containing oligomers is developed. It relies on the transformation of the (diisopropylamino)boryl group (-BH(NiPr2)) into a dioxazaborocane unit in the presence β-aminodiols and involves a bis-borylated dithienylethene photochromic unit. The photophysical properties of the obtained oligomers are evaluated as well as their processability for the preparation of spin-coated films. The photomechanical behavior of the resulting films is assessed via displacement tracking profile., (© 2024 Wiley‐VCH GmbH.)

A blue fluorescent tetraphenylethylene-based dication and a red-NIR phosphorescent rhenium octahedral cluster tetra-anion are associated electrostatically to generate a supramolecular ionic framework which crystallizes in the P 1̄ centric space group. The emission properties of the hybrids are studied in the crystalline state and in solution revealing a resonant energy transfer and a high sensitivity toward oxygen.

The use of low-cost depth imaging sensors is investigated to automate plant pathology tests. Spatial evolution is explored to discriminate plant resistance through the hypersensitive reaction involving cotyledon loss. A high temporal frame rate and a protocol operating with batches of plants enable to compensate for the low spatial resolution of depth cameras. Despite the high density of plants, a spatial drop of the depth is observed when the cotyledon loss occurs. We introduce a small and simple spatiotemporal feature space which is shown to carry enough information to automate the discrimination between batches of resistant (loss of cotyledons) and susceptible plants (no loss of cotyledons) with 97% accuracy and with a timing 30 times faster than for human annotation. The robustness of the method-in terms of density of plants in the batch and possible internal batch desynchronization-is assessed successfully with hundreds of varieties of Pepper in various environments. A study on the generalizability of the method suggests that it can be extended to other pathosystems and also to segregating plants, i.e., intermediate state with batches composed of resistant and susceptible plants. The imaging system developed, combined with the feature extraction method and classification model, provides a full pipeline with unequaled throughput and cost efficiency by comparison with the state-of-the-art one. This system can be deployed as a decision-support tool but is also compatible with a standalone technology where computation is done at the edge in real time., Competing Interests: Competing interests: The authors declare that there is no conflict of interest regarding the publication of this article., (Copyright © 2024 Mathis Cordier et al.)

Alkane elimination reactions between the diamino- and dianilino-bridged tetrakis(phenolate) proligands 1a,b-H and precursors M(CH 4 and precursors M(CH 2 SiMe 3 ) 3 , M(CH 2 , M(CH 2 C 6 H 4 - o -NMe 2 (M = Sc and Y), and Hf(CH 3 (M = Sc and Y), and Hf(CH 2 Ph) 4 were investigated. The diamino-bridged 1a-H 4 afforded nonsymmetric complex 2a-Y 2 incorporating two metal centers in different coordination environments. This one and other dinuclear compounds 2b-Sc 2 , 2a-Hf 2 , and 2b-Hf 2 were characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction study (for 2a-Y 2 and 2b-Sc 2 ) and turned out to be symmetric in solution. Compound 2a-Y 2 , upon treatment with 2 equiv of 2-phenylpyridine, afforded symmetric bis(aryl) product 3a-Y 2 , which was authenticated by NMR spectroscopy and X-ray crystallography. The mechanism of its formation was studied by DFT computations and presumably involves a cooperative reorganization process within the nonsymmetric parent 2a-Y 2 to afford a symmetric isomer prior to its reaction with 2-phenylpyridine.

The synthetic scope of 3-arylated tetrazo[1,2- b ]indazoles is reported based on a Pd-catalyzed Liebeskind-Srogl cross-coupling reaction followed by an N-cyclisation process. The reactivity of the nitrogen atoms was used to further diversify these N-rich polyaromatic tetrazo[1,2- b ]indazoles in a panel of reactions (protonation, selective oxidation, metallations). Selective ortho -C-H activation/functionalization on the heterocycle was also demonstrated with three transition metals (TM = Pd, Ir and Rh). The effects of all these molecular engineering strategies, particularly the N-modifications, on the optical and redox properties of the 3-arylated tetrazoindazoles were studied experimentally and theoretically. This study highlights the diversity of molecular structures and electronic properties offered by the tetrazo[1,2- b ]indazole platform.

We provide a comprehensive study of the coordination of oxocyclam with palladium(II), including presentation of a novel bifunctional analogue, p -H 2 N-Bn-oxocyclam, bearing an aniline pendant. The complexation of palladium(II) with oxocyclam was examined by various techniques, including NMR analysis and potentiometric titrations which revealed that the Pd(II) complex can adopt different configurations such as trans -I and trans -III. In addition, oxocyclam forms a thermodynamically stable palladium(II) complex, the stabilization being attributed to the deprotonation of the amide function. The crystal structures of [Pd(H -1 oxocyclam )] + and [Pd( oxocyclam )] 2+ were obtained, revealing the structural details previously anticipated, including, in the second case, the presence of the proton on the carbonyl oxygen atom. Additionally, the study explored the redox behavior of the Pd(II)- oxocyclam complex through reduction and oxidation voltammograms at different pH values. Successful 109 Pd-labeling of oxocyclam and p -H 2 N-Bn-oxocyclam at pH 3.5 demonstrated high labeling efficiencies, whatever the species formed. The stability of the radiocomplexes was assessed and moderate transchelation toward EDTA was observed. Overall, oxocyclam displayed favorable properties for Pd(II) coordination and radiolabeling, suggesting its potential as a chelating agent for this metal in palladium-based applications.

In this report, we address the challenge of assigning diastereomers for methyl cyclohexanes, particularly those with quaternary centers, which remains nontrivial despite modern NMR techniques. By utilizing a HSQC NMR experiment to identify methyl-carbons coupled with a simple conformational analysis, we identified an effective and quite general method for assigning stereochemistry, even in cases where diastereomeric mixtures are inseparable.

We report on the synthesis, structure and reactivity of [{NCN Me4 }Sb(C 6 H 2 - t Bu 2 -3,5-O-4)] (3), an organoantimony(III)-oxyaryl species obtained upon C sp 2 -H bond activation in a phenolate ligand and stabilised by the monoanionic pincer {NCN Me4 } - . The mechanism leading to the formation of 3 is highly sensitive to steric considerations. It was probed experimentally and by DFT calculations, and a number of intermediates and related complexes were identified. All data agree with successive heterolytic bond cleaving and bond forming processes involving charged species, rather than a pathway involving free radicals as previously exemplified with congeneric bismuth species. The nucleophilic behaviour of the oxyaryl ligand in 3, a complex that features both zwitterionic and quinoidal attributes, was illustrated in derivatisation reactions. In particular, insertion of CS 2 in the Sb-C oxyaryl bond generates [{NCN Me4 }Sb(S 2 C-C 6 H 2 - t Bu 2 -3,5-O-4)].

Under mechanical stimulation, a copper(I) complex in its supercooled liquid state transforms into a crystalline phase, showing a dramatic emission color change from red to green that is accompanied by a 20-fold increase in the photoluminescence quantum yield up to 87%. This reversible phase transition relies on the intriguing ability of this copper complex to form a supercooled metastable state.

Emissive ionic supramolecular frameworks are designed by associating tetraphenylethylene-based tetra-cationic units and di-anionic molybdenum or tetra-anionic rhenium octahedral clusters. Obtained structures were characterized by single-crystal X-ray diffraction. The emission properties of the hybrids were investigated as dry powders or in various solvents by one photon and two photon absorption leading to a O 2 concentration dependent luminescence color for the Mo based hybrid., (© 2024 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)