Acenes, especially tetracene derivatives, are used as singlet fission materials. The recent synthesis of Dodecaphenyl tetracene (showing end-to-end twist angles of 96-98 degrees) and twisted anthracene derivatives show that the synthesis of twisted linear oligoacenes is possible. Energy calculations and NICS-X-scan studies predict the twisted acenes may be better singlet fission materials compared to their planar analogues.

CF3-substituted cyclopropyl carbinol derivatives undergo regioselective and diastereoselective nucleophilic halogenation at the quaternary carbon center to provide acyclic products as a single diastereomer. The selectivity of the substitution is rationalized by the formation of a nonclassical cyclopropylcarbinyl cation intermediate, reacting at the most-substituted carbon center. Tertiary alkyl chlorides, bromides, and fluorides adjacent to a stereogenic C–CF3-motif are diastereomerically pure and can be obtained in few catalytic steps from commercially available alkynes.

Light harvesting in nature is one of the most important processes, starting with the absorption of light by chromophores within proteins and the transfer of energy from one another via the Förster resonance energy transfer (FRET) mechanism. If the energy is transferred between identical chromophores, the resulting is Homo-FRET. Here, we introduce an artificial system that allows us to control the number of chromophores within a certain protein and to decipher the mechanism of Homo-FRET in proteins in ways not possible in biological systems. We follow Homo-FRET by ultrafast fluorescence anisotropy measurements. We show that for solvated proteins, the mechanism, rate, and efficiency of Homo-FRET are highly dependent on the number of chromophores within the protein. However, in the solid protein matrix, the mechanism remains the same as the number of chromophores increases, but the solid matrix allows long-range Homo-FRET, resulting in full depolarization. The observed higher-than-ideal Homo-FRET contribution to the observed fluorescence anisotropy decay together with the reduction in the limiting anisotropy suggest a mixed coherent-incoherent mechanism of energy transfer.

Asymmetric catalysis with phosphine free ligands is a rapidly developing field where N-heterocyclic carbenes (NHCs) are making increasingly more impact. Herein, we report the synthesis and characterization of carbene-oxazoline containing proligands that exhibit two chiral centers. The corresponding rhodium(I) complexes show excellent activity toward the asymmetric hydroboration of styrenes, which occurs with good regio– and enantioselectivity (up to 96% ee). The resulting boronic esters were subsequently oxidized, and the corresponding chiral alcohols were isolated in moderate to good yields (up to 75%). Overall, the hydroboration reaction occurs under ambient conditions (CH₂Cl₂; 25 °C), is compatible with a variety of functional groups, and provides easy access to chiral secondary alcohols from the corresponding alkenes.

Polymeric ion conductors composed of a polymeric matrix associated with an isoindolinium moiety represented by Formula I as described in the specification are provided. Anion conducting compositions comprising an anion conducting polymer associated with, or threaded within and having mechanically interlocked therearound, a cyclic moiety are also provided. lonomeric materials, including, for example, ion exchange membranes such as anion exchange membranes, made of the polymeric ion conductor and/or the anion conducting composition, and electrochemical systems and articles-of-manufacturing containing the polymeric ion conductor, the anion conducting composition or the ion exchange membrane are also provided.

In the search for mild agents for the oxidative cyclization of tetrapyrromethane to the corresponding corrole, we discovered a route that leads to a monoazaporphyrin with three meso-CF₃ groups. Optimization studies that allowed access to appreciable amounts of this new macrocycle paved the way for the preparation of its cobalt, copper, nickel, zinc, and iron complexes. All complexes were fully characterized by various spectroscopic methods and X-ray crystallography. Their photophysical and electrochemical properties were determined and compared to those of analogous porphyrins in order to deduce the effect of the peripheral N atom. Considering the global efforts for designing efficient alternatives to platinum group metal (PGM) catalysts, they were also absorbed onto a porous carbon electrode material and studied as electrocatalysts for the oxygen reduction reaction (ORR). The cobalt complex was found to be operative at a quite positive catalytic onset potential and with good selectivity for the desirable 4-electrons/4-protons pathway.

The exploration of two-dimensional (2D) antiferromagnetic (AFM) materials has shown great promise and interest in tuning the magnetic and electronic properties as well as studding magneto-optical effects. The current work investigates the control of magneto-optical interactions in alloyed MnxZn1-xPS3¬ lamellar semiconductor single crystals, with the Mn/Zn ratio regulating the coupling strength. Magnetic susceptibility results show a retention of AFM order followed by a decrease in Néel temperatures down to ~ 40% Mn concentration, below which a paramagnetic behavior is observed. Absorption measurements reveal an increase in bandgap energy with higher Zn(II) concentration, and the presence of Mn(II) d-d transition below the absorption edge. DFT+U approach qualitatively explained the origin and the position of the experimentally observed mid band-gap states in pure MnPS3, and corresponding peaks visible in the alloyed systems MnxZn1-xPS3. Accordingly, emission at 1.3 eV in all alloyed compounds results from recombination from a 4T1g Mn(II) excited state to a hybrid p-d state at the valence band. Most significant, temperature-dependent photoluminescence (PL) intensity trends demonstrate strong magneto-optical coupling in compositions with x > 0.65. This study underscores the potential of tailored alloy compositions as a means to control magnetic and optical properties in 2D materials, paving the way for advances in spin-based technologies.

The skeletal editing of azaarenes through insertion, deletion, or swapping of single atoms has recently gained considerable momentum in chemical synthesis. Here, we describe a practical skeletal editing strategy using vinylcarbenes in-situ generated from trifluoromethyl vinyl N-triftosylhydrazones, leading to the first dearomative skeletal editing of pyrroles through carbon-atom insertion. Furthermore, depending on the used catalyst and substrate, three types of peripheral editing reactions of pyrroles are also disclosed: α- or γ-selective C–H insertion, and [3+2] cycloaddition. These controllable molecular editing reactions provide a powerful platform for accessing medicinally relevant CF3-containing N-heterocyclic frameworks, such as 2,5-dihydropyridines, piperidines, azabicyclo[3.3.0]octadienes, and allylated pyrroles from readily available pyrroles. Mechanistic insights from experiments and density functional theory (DFT) calculations shed light on the origin of substrate- or catalyst-controlled chemo- and regioselectivity as well as the reaction mechanism.

Nitrogen-terminated diamonds hold promise for stabilizing near-surface NV⁻ centers, which is essential for reliable quantum sensing. Among various surface preparation methods, microwave (MW) nitrogen plasma, known for its minimal surface damage, appears as the most effective choice. In this investigation, we explore the nature of nitrogen bonding of polycrystalline diamond (PCD) surfaces exposed to MW nitrogen plasma using X-ray Photoelectron Spectroscopy (XPS) depth profiling and Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy at the C K- and N K-edges. XPS depth profiling with atomic resolution, achieved by varying the probing photon energy using synchrotron radiation and supported by a physical model considering the associated inelastic mean free path, suggests a surface of almost fully saturated nitrogen in two main bonding configurations of similar contribution and a low coverage of ∼5 % of graphene-like islands residing atop the nitrogen-terminated diamond surface. The thermal stability of these surface groups is monitored by in situ annealing up to 700 °C. The depth profiles reveal that nitrogen atoms do not diffuse in the diamond crystal, resulting in excellent diamond crystallinity in the first atomic planes below the surface. C K-edge NEXAFS analysis reveals the position of unoccupied surface states within the diamond bandgap, opening new perspective on the stabilization of near-surface NV⁻ centers.

In this paper, we report the quantitative synthesis of the first Pt-silene -complex and its unusual interaction with benzene molecule in the solid state, revealed by X-ray crystallography. Thus, three platinum complexes dock on one benzene molecule via weak van der Waals-type interactions with the benzene hydrogens. The cyclopropane nature of the complex was confirmed by 29Si NMR spectroscopy and molecular structure. Also, an unusual situation in 31P NMR was observed, in which two phosphorus atoms with different chemical environments have similar chemical shifts but different values of J-coupling with platinum.