Compression of curium pyrrolidine-dithiocarbamate enhances covalency.

Curium is unique in the actinide series because its half-filled 5f 7 shell has lower energy than other 5f n configurations, rendering it both redox-inactive and resistant to forming chemical bonds that engage the 5f shell1-3. This is even more pronounced in gadolinium, curium's lanthanide analogue, owing to the contraction of the 4f orbitals with respect to the 5f orbitals4. However, at high pressures metallic curium undergoes a transition from localized to itinerant 5f electrons5. This transition is accompanied by a crystal structure dictated by the magnetic interactions between curium atoms5,6. Therefore, the question arises of whether the frontier metal orbitals in curium(III)-ligand interactions can also be modified by applying pressure, and thus be induced to form metal-ligand bonds with a degree of covalency. Here we report experimental and computational evidence for changes in the relative roles of the 5f/6d orbitals in curium-sulfur bonds in [Cm(pydtc)4]- (pydtc, pyrrolidinedithiocarbamate) at high pressures (up to 11 gigapascals). We compare these results to the spectra of [Nd(pydtc)4]- and of a Cm(III) mellitate that possesses only curium-oxygen bonds. Compared with the changes observed in the [Cm(pydtc)4]- spectra, we observe smaller changes in the f-f transitions in the [Nd(pydtc)4]- absorption spectrum and in the f-f emission spectrum of the Cm(III) mellitate upon pressurization, which are related to the smaller perturbation of the nature of their bonds. These results reveal that the metal orbital contributions to the curium-sulfur bonds are considerably enhanced at high pressures and that the 5f orbital involvement doubles between 0 and 11 gigapascal. Our work implies that covalency in actinides is complex even when dealing with the same ion, but it could guide the selection of ligands to study the effect of pressure on actinide compounds.

Tethering Three Radical Cascades for Controlled Termination of Radical Alkyne peri-Annulations: Making Phenalenyl Ketones without Oxidants.

Although Bu3Sn-mediated radical alkyne peri-annulations allow access to phenalenyl ring systems, the oxidative termination of these cascades provides only a limited selection of the possible isomeric phenalenone products with product selectivity controlled by the intrinsic properties of the new cyclic systems. In this work, we report an oxidant-free termination strategy that can overcome this limitation and enable selective access to the full set of isomerically functionalized phenalenones. The key to preferential termination is the preinstallation of a "weak link" that undergoes C-O fragmentation in the final cascade step. Breaking a C-O bond is assisted by entropy, gain of conjugation in the product, and release of stabilized radical fragments. This strategy is expanded to radical exo-dig cyclization cascades of oligoalkynes, which provide access to isomeric π-extended phenalenones. Conveniently, these cascades introduce functionalities (i.e., Bu3Sn and iodide moieties) amenable to further cross-coupling reactions. Consequently, a variety of polyaromatic diones, which could serve as phenalenyl-based open-shell precursors, can be synthesized.

Correction: Extracting accurate information from triplet-triplet annihilation upconversion data with a mass-conserving kinetic model.

Correction for 'Extracting accurate information from triplet-triplet annihilation upconversion data with a mass-conserving kinetic model' by Abhishek Kalpattu et al., Phys. Chem. Chem. Phys., 2022, 24, 28174-28190, https://doi.org/10.1039/D2CP03986A.

Sex Doll Specifications versus Human Body Characteristics.

Sex dolls have been criticized for reproducing unrealistic expectations about human bodies. Yet precise sex doll measurements are lacking in the literature nor has there been any systematic attempt to determine the extent to which sex dolls exaggerate human characteristics. To address this gap, we compared the specifications of sex dolls marketed in the USA with the characteristics of women and men living in the USA. Specifically, we tested if and to what degree female dolls were slimmer (H1) and male dolls more muscular (H2) than female and male humans, respectively. Furthermore, we tested if and to what degree female dolls' breasts (H3) and male dolls' penises (H4) were larger than those of women and men. We also tested if sex dolls' observed race/ethnicity was more often White than that of the US population (H5). In 2023, we collected the measures of all 757 full-body sex dolls marketed by the US retailer SexyRealSexDolls.com. Body measures from the US population were extracted from scientific literature. Descriptive and inferential statistical analyses were performed using R. All hypotheses were fully or partially confirmed, which indicated that sex dolls marketed in the USA are not realistic depictions of the US population but hypergendered (H1, H2), hypersexualized (H3, H4), and racially fetishized (H5). Implications of the lack of realism are discussed.

Molecular Orientation and Energy Transfer Dynamics of a Metal Oxide Bound Self-Assembled Trilayer.

Self-assembly of molecular multilayers via metal ion linkages has become an important strategy for interfacial engineering of metalloid and metal oxide (MOx) substrates, with applications in numerous areas, including energy harvesting, catalysis, and chemical sensing. An important aspect for the rational design of these multilayers is knowledge of the molecular structure-function relationships. For example, in a multilayer composed of different chromophores in each layer, the molecular orientation of each layer, both relative to the adjacent layers and the substrate, influences the efficiency of vectorial energy and electron transfer. Here, we describe an approach using UV-vis attenuated total reflection (ATR) spectroscopy to determine the mean dipole tilt angle of chromophores in each layer in a metal ion-linked trilayer self-assembled on indium-tin oxide. To our knowledge, this is the first report demonstrating the measurement of the orientation of three different chromophores in a single assembly. The ATR approach allows the adsorption of each layer to be monitored in real-time, and any changes in the orientation of an underlying layer arising from the adsorption of an overlying layer can be detected. We also performed transient absorption spectroscopy to monitor interlayer energy transfer dynamics in order to relate structure to function. We found that near unity efficiency, sub-nanosecond energy transfer between the third and second layer was primarily dictated by the distance between the chromophores. Thus, in this case, the orientation had minimal impact at such proximity.

Exploring Differences in Lanthanide Excited State Reactivity Using a Simple Example: The Photophysics of La and Ce Thenoyltrifluoroacetone Complexes.

A series of four lanthanide thenoyltrifluoroacetone (TTA) complexes consisting of two f0 (La3+ and Ce4+) and two f1 (Ce3+) complexes was examined using steady-state and time-resolved spectroscopic techniques. The wide range of spectroscopic techniques presented herein have enabled us to discern the nature of the excited states (charge transfer, CT vs ligand localized, LL) as well as construct a Jablonski diagram for detailing the excited state reactivity within the series of molecules. The wavelength and excitation power dependence for these series of complexes are the first direct verification for the presence of simultaneous competing, noninteracting CT and LL excited states. Additionally, a computational framework is described that can be used to support spectroscopic assignments as a guide for future studies. Finally, the relationship between the obtained photophysics and possible photochemical separation mechanisms is described.

EMS Care of Adult Hospice Patients- a Position Statement and Resource Document of NAEMSP and AAHPM.

Emergency medical services (EMS) systems are designed to provide care in the field and while transporting patients to a hospital; however, patients enrolled in hospice may not want invasive therapies nor benefit from hospitalization. For many reasons, encounters with hospice patients can be challenging for EMS systems, EMS clinicians, hospice clinicians, hospice patients, and their families.

EMS clinicians should receive hospice-focused education that fosters a basic understanding of hospice, palliative therapies, and advance care planning documents (e.g., Physician Orders for Life Sustaining Treatment). This education should emphasize the ongoing development of end-of-life communication skills.EMS medical directors and local hospice organizations should collaborate to develop hospice patient-centered EMS protocols that address symptom management and delineate appropriate and goal concordant clinical interventions, and that are within the agency-level scope of practice for local EMS clinicians. Partnerships between EMS and hospice organizations can facilitate access to hospice teams who can provide clear guidance on whether to treat-in-place with follow-up care or to transport hospice patients to the hospital.EMS medical directors and local hospice organizations should collaborate to perform needs assessments of hospice patient EMS utilization.EMS medical directors should consider including a focus on EMS care of hospice patients as part of their overall quality management program(s). Ideally these efforts should be collaborative with local hospice agencies in order to facilitate meaningful process improvement strategies that include both EMS and hospice stakeholders.Reimbursement programs should reasonably compensate EMS agencies for scene treatment in place, as well as transport to alternative destinations such as in-patient hospice facilities.

Influence of Al2O3 Overlayers on Intermolecular Interactions between Metal Oxide Bound Molecules.

Intermolecular interactions on inorganic substrates can have a critical impact on the electrochemical and photophysical properties of the materials and subsequent performance in hybrid electronics. Critical to the intentional formation or inhibition of these processes is controlling interactions between molecules on a surface. In this report, we investigated the impact of surface loading and atomic-layer-deposited Al2O3 overlayers on the intermolecular interactions of a ZrO2-bound anthracene derivative as probed by the photophysical properties of the interface. While surface loading density had no impact on the absorption spectra of the films, there was an increase in excimer features with surface loading as observed by both emission and transient absorption. The addition of ALD overlayers of Al2O3 resulted in a decrease in excimer formation, but the emission and transient absorption spectra were still dominated by excimer features. These results suggest that ALD may provide a post-surface loading means of influencing such intermolecular interactions.

Molecular Z-Scheme for Solar Fuel Production via Dual Photocatalytic Cycles.

Natural photosynthesis uses an array of molecular structures in a multiphoton Z-scheme for the conversion of light energy into chemical bonds (i.e., solar fuels). Here, we show that upon excitation of both a molecular photocatalyst (PC) and a substituted naphthol (ROH) in the presence of a sacrificial electron donor and proton source, we achieve photocatalytic synthesis of H2. Data support a multiphoton mechanism that is catalytic with respect to both PC and ROH. The use of a naphthol molecule as both a light absorber and H2 producing catalyst is a unique motif for Z-scheme systems. This molecular Z-scheme can drive a reaction that is uphill by 511 kJ mol-1 and circumvents the high-energy constraints associated with the reduction of weak acids in their ground state, thus offering a new paradigm for the production of solar fuels.

Assessing Carbazole Derivatives as Single-Electron Photoreductants.

The electron-donating capabilities of carbazoles have stimulated interest in their use as photoinduced single-electron reductants. Due to the modularity of the carbazole, a further broadening and understanding of their reactivity could be achieved by manipulating the structure. Herein, eight carbazole derivatives were synthesized, characterized, and assessed as single-electron photoreductants in the hydrodehalogenation of aryl halides and the arylation of N-methylpyrrole.

Extracting accurate information from triplet-triplet annihilation upconversion data with a mass-conserving kinetic model.

Triplet-triplet annihilation upconversion (TTA-UC) is a process that shows promise for applications such as energy-harvesting and light-generation technologies. The irradiance dependent performance of TTA-UC systems is typically gauged using a graphical analysis, rather than a detailed model. Additionally, kinetic models for TTA-UC rarely incorporate mass conservation, which is a phenomenon that can have important consequences under experimentally relevant conditions. We present an analytical, mass-conserving kinetic model for TTA-UC, and demonstrate that the mass-conservation constraint cannot generally be ignored. This model accounts for saturation in TTA-UC data. Saturation complicates the interpretation of the threshold irradiance Ith, a popular performance metric. We propose two alternative figures of merit for overall performance. Finally, we show that our model can robustly fit experimental data from a wide variety of sensitized TTA-UC systems, enabling the direct and accurate determination of Ith and of our proposed performance metrics. We employ this fitting procedure to benchmark and compare these metrics, using data from the literature.

Enhanced Diastereocontrol via Strong Light-Matter Interactions in an Optical Cavity.

The enantiopurification of racemic mixtures of chiral molecules is important for a range of applications. Recent work has shown that chiral group-directed photoisomerization is a promising approach to enantioenrich racemic mixtures of BINOL, but increased control of the diasteriomeric excess (de) is necessary for its broad utility. Here we develop a cavity quantum electrodynamics (QED) generalization of time-dependent density functional theory and demonstrate computationally that strong light-matter coupling can alter the de of the chiral group-directed photoisomerization of BINOL. The relative orientation of the cavity mode polarization and the molecules in the cavity dictates the nature of the cavity interactions, which either enhance the de of the (R)-BINOL diasteriomer (from 17% to ≈40%) or invert the favorability to the (S)-BINOL derivative (to ≈34% de). The latter outcome is particularly remarkable because it indicates that the preference in diasteriomer can be influenced via orientational control, without changing the chirality of the directing group. We demonstrate that the observed effect stems from cavity-induced changes to the Kohn-Sham orbitals of the ground state.

Synthesis of multi-substituted pyridines from ylidenemalononitriles and their emission properties.

Numerous methodologies to obtain pyridines from ylidenemalononitriles are described in the literature. Nevertheless, they are limited to the use of microwave or conventional heat and few lead to 2,3,4 or 2,3,4,5-substituted pyridines as multi-proposal molecular scaffolds or even universal pyridines. Herein, we present a mild and facile solvent-free methodology to obtain a scope of multi-substituted pyridines at room temperature. We also report an example where one of the resulting amino-nicotinonitriles exhibits a preliminary evidence of aggregation-induced emission (AIE).

Highly Efficient and Stable Perovskite Solar Cells Enabled by Low-Cost Industrial Organic Pigment Coating.

Surface passivation of perovskite solar cells (PSCs) using a low-cost industrial organic pigment quinacridone (QA) is presented. The procedure involves solution processing a soluble derivative of QA, N,N-bis(tert-butyloxycarbonyl)-quinacridone (TBOC-QA), followed by thermal annealing to convert TBOC-QA into insoluble QA. With halide perovskite thin films coated by QA, PSCs based on methylammonium lead iodide (MAPbI3 ) showed significantly improved performance with remarkable stability. A PCE of 21.1 % was achieved, which is much higher than 18.9 % recorded for the unmodified devices. The QA coating with exceptional insolubility and hydrophobicity also led to greatly enhanced contact angle from 35.6° for the pristine MAPbI3 thin films to 77.2° for QA coated MAPbI3 thin films. The stability of QA passivated MAPbI3 perovskite thin films and PSCs were significantly enhanced, retaining about 90 % of the initial efficiencies after more than 1000 hours storage under ambient conditions.

Twofold π-Extension of Polyarenes via Double and Triple Radical Alkyne peri-Annulations: Radical Cascades Converging on the Same Aromatic Core.

A versatile synthetic route to distannyl-substituted polyarenes was developed via double radical peri-annulations. The cyclization precursors were equipped with propargylic OMe traceless directing groups (TDGs) for regioselective Sn-radical attack at the triple bonds. The two peri-annulations converge at a variety of polycyclic cores to yield expanded difunctionalized polycyclic aromatic hydrocarbons (PAHs). This approach can be extended to triple peri-annulations, where annulations are coupled with a radical cascade that connects two preexisting aromatic cores via a formal C-H activation step. The installed Bu3Sn groups serve as chemical handles for further functionalization via direct cross-coupling, iodination, or protodestannylation and increase solubility of the products in organic solvents. Photophysical studies reveal that the Bu3Sn-substituted PAHs are moderately fluorescent, and their protodestannylation results in an up to 10-fold fluorescence quantum yield enhancement. DFT calculations identified the most likely possible mechanism of this complex chemical transformation involving two independent peri-cyclizations at the central core.

Increasing Scope of Clickable Fluorophores: Electrophilic Substitution of Ylidenemalononitriles.

Recently, we demonstrated that ylidenemalononitriles (YMs) react with amines to form cyclic amidines and that the starting linear YMs are nonemissive in solution and the cyclic amidines are fluorescent. These turn-on systems were of interest to us because of their potential as biosensors and synthons for accessing functionalized pyridines. While our original method was promising, several limitations persisted, including access to more functionalized and polar-solvent-soluble structures as well as increased control over the rate of cyclization. Herein, we report a new approach that allows the electrophilic substitution of YMs. These substituted YMs exhibit faster turn-on rates, color tunability, access to polar-solvent-soluble species, and increased control over cyclization rate. This allowed us to significantly expand the fluorophore's chemical space.

Conversion of Trivalent Uranium Anilido to Tetravalent Uranium Imido Species via Oxidative Deprotonation.

Two uranium(III) anilido complexes were synthesized, Tp*2U(NH-C6H4-p-terpyridine) (2-terpy) and Tp*2U(NH-C6H4-p-CH3) (2-ptol), where Tp* = hydrotris(3,5-dimethylpyrazolyl)borate, by protonation of Tp*2UBn (1-Bn; Bn = benzyl) with 4-[2,6-di(pyridin-2-yl)pyridin-4-yl]benzenamine or p-toluidine, respectively. Conversion to the respective uranium(IV) imido species was possible by oxidation and deprotonation, forming Tp*2U(N-C6H4-p-terpyridine) (3-terpy) and Tp*2U(N-C6H4-p-CH3) (3-ptol). These compounds were characterized by multinuclear NMR spectroscopy, IR spectroscopy, electronic absorption spectroscopy, and X-ray crystallography.

Bis-Cyclometalated Iridium Complexes Containing 4,4'-Bis(phosphonomethyl)-2,2'-bipyridine Ligands: Photophysics, Electrochemistry, and High-Voltage Dye-Sensitized Solar Cells.

In this report, the synthesis and characterization of two bis-cyclometalated iridium(III) complexes are presented. Single-crystal X-ray diffraction shows that [Ir(ppy)2(4,4'-bis(diethylphosphonomethyl)-2,2'-bipyridine)]PF6 adopts a pseudooctahedral geometry. The complexes have an absorption feature in the near-visible-UV region and emit green light with excited-state lifetimes in hundreds of nanoseconds. The redox properties of these complexes show reversible behavior for both oxidative and reductive events. [Ir(ppy)2(4,4'-bis(phosphonomethyl)-2,2'-bipyridine)]PF6 readily binds to metal oxide supports, like nanostructured SnIV-doped In2O3 and TiO2, while still retaining reversible redox chemistry. When incorporated as the photoanode in dye-sensitized solar cells, the devices exhibit open-circuit voltages of >1 V, which is a testament to their strength of these iridium(III) complexes as photochemical oxidants.

Phenalenannulations: Three-Point Double Annulation Reactions that Convert Benzenes into Pyrenes.

3-Point annulations, or phenalenannulations, transform a benzene ring directly into a substituted pyrene by "wrapping" two new cycles around the perimeter of the central ring at three consecutive carbon atoms. This efficient, modular, and general method for π-extension opens access to non-symmetric pyrenes and their expanded analogues. Potentially, this approach can convert any aromatic ring bearing a -CH2 Br or a -CHO group into a pyrene moiety. Depending upon the workup choices, the process can be directed towards either tin- or iodo-substituted product formation, giving complementary choices for further various cross-coupling reactions. The two-directional bis-double annulation adds two new polyaromatic extensions with a total of six new aromatic rings at a central core.

Solid State Multicolor Emission in Substitutional Solid Solutions of Metal-Organic Frameworks.

Preparing crystalline materials that produce tunable organic-based multicolor emission is a challenge due to the inherent inability to control the packing of organic molecules in the solid state. Utilizing multivariate, high-symmetry metal-organic frameworks, MOFs, as matrices for organic-based substitutional solid solutions allows for the incorporation of multiple fluorophores with different emission profiles into a single material. By combining nonfluorescent links with dilute mixtures of red, green, and blue fluorescent links, we prepared zirconia-type MOFs and found that the bulk materials exhibit features of solution-like fluorescence. Our study found that MOFs with a fluorophore link concentration of around 1 mol % exhibit fluorescence with decreased inner filtering, demonstrated by changes in spectral profiles, increased quantum yields, and lifetime dynamics expected for excited-state proton-transfer emitters. Our findings enabled us to prepare organic-based substitutional solid solutions with tunable chromaticity regulated only by the initial amounts of fluorophores. These materials emit multicolor and white light with high quantum yields (∼2-14%), high color-rendering indices (>93), long shelf life, and superb hydrolytic stability at ambient conditions.