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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Sb(PO3)4 by Materials Project

Sb(PO3)4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Sb–O bond distances ranging from 2.11–2.21 Å. There are two inequivalent P+4.75+ sites. In the first P+4.75+ site, P+4.75+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent SbO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–49°. There are a spread of P–O bond distances ranging from 1.52–1.61 Å. In the second P+4.75+ site, P+4.75+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SbO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. There are a spread of P–O bond distances ranging from 1.46–1.66 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent P+4.75+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Sb5+ and one P+4.75+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two P+4.75+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sb5+ and one P+4.75+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one P+4.75+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Sb5+ and one P+4.75+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent P+4.75+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sb(PO3)4 by Materials Project

Sb(PO3)4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Sb–O bond distances ranging from 2.12–2.17 Å. There are two inequivalent P+4.75+ sites. In the first P+4.75+ site, P+4.75+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent SbO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–53°. There are a spread of P–O bond distances ranging from 1.51–1.59 Å. In the second P+4.75+ site, P+4.75+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SbO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of P–O bond distances ranging from 1.46–1.66 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Sb5+ and one P+4.75+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sb5+ and one P+4.75+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P+4.75+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two P+4.75+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sb5+ and one P+4.75+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to one P+4.75+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sb(PO3)4 by Materials Project

Sb(PO3)4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Sb5+ is bonded to six O2- atoms to form distorted SbO6 octahedra that share corners with four PO4 tetrahedra and an edgeedge with one PO4 tetrahedra. There are a spread of Sb–O bond distances ranging from 2.02–2.39 Å. There are four inequivalent P+4.75+ sites. In the first P+4.75+ site, P+4.75+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SbO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedral tilt angles are 65°. There are a spread of P–O bond distances ranging from 1.46–1.64 Å. In the second P+4.75+ site, P+4.75+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent SbO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–37°. There are a spread of P–O bond distances ranging from 1.51–1.60 Å. In the third P+4.75+ site, P+4.75+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two PO4 tetrahedra and an edgeedge with one SbO6 octahedra. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. In the fourth P+4.75+ site, P+4.75+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SbO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. There are a spread of P–O bond distances ranging from 1.47–1.61 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Sb5+ and one P+4.75+ atom. In the second O2- site, O2- is bonded in a distorted L-shaped geometry to one Sb5+ and one P+4.75+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Sb5+ and one P+4.75+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Sb5+ and one P+4.75+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two P+4.75+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Sb5+ and one P+4.75+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one P+4.75+ atom. In the eighth O2- site, O2- is bonded in a single-bond geometry to one P+4.75+ atom. In the ninth O2- site, O2- is bonded in a linear geometry to two P+4.75+ atoms. In the tenth O2- site, O2- is bonded in a distorted single-bond geometry to one Sb5+ and one P+4.75+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to two P+4.75+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two P+4.75+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sb(WO3)5 by Materials Project

Sb(WO3)5 crystallizes in the orthorhombic Cmme space group. The structure is three-dimensional. there are three inequivalent W+5.40+ sites. In the first W+5.40+ site, W+5.40+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 3–43°. There are a spread of W–O bond distances ranging from 1.91–2.11 Å. In the second W+5.40+ site, W+5.40+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 3–38°. There are a spread of W–O bond distances ranging from 1.92–2.03 Å. In the third W+5.40+ site, W+5.40+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–43°. There are a spread of W–O bond distances ranging from 1.85–2.09 Å. Sb3+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (2.11 Å) and two longer (2.75 Å) Sb–O bond lengths. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent W+5.40+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two W+5.40+ and one Sb3+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two W+5.40+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two W+5.40+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two W+5.40+ atoms. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two W+5.40+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two W+5.40+ and one Sb3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Phase‐Change‐Memory Process at the Limit: A Proposal for Utilizing Monolayer Sb 2 Te 3

Abstract One central task of developing nonvolatile phase change memory (PCM) is to improve its scalability for high‐density data integration. In this work, by first‐principles molecular dynamics, to date the thinnest PCM material possible (0.8 nm), namely, a monolayer Sb 2 Te 3 , is proposed. Importantly, its SET (crystallization) process is a fast one‐step transition from amorphous to hexagonal phase without the usual intermediate cubic phase. An increased spatial localization of electrons due to geometrical confinement is found to be beneficial for keeping the data nonvolatile in the amorphous phase at the 2D limit. The substrate and superstrate can be utilized to control the phase change behavior: e.g., with passivated SiO 2 (001) surfaces or hexagonal Boron Nitride, the monolayer Sb 2 Te 3 can reach SET recrystallization in 0.54 ns or even as fast as 0.12 ns, but with unpassivated SiO 2 (001), this would not be possible. Besides, working with small volume PCM materials is also a natural way to lower power consumption. Therefore, the proposed PCM working process at the 2D limit will be an important potential strategy of scaling the current PCM materials for ultrahigh‐density data storage.

2D limit↗
DOE OSTI2025

Characterization of Cs 3 Sb photocathodes at cryogenic temperatures

Here, we report measurements of quantum efficiency (QE) and mean transverse energy (MTE) from Cs 3 Sb photocathodes in a wide range of photon energies at both room and cryogenic temperatures. Our measurements show a strong temperature dependence of MTE even at photon energies well above threshold, indicating the presence of strong inelastic scattering of excited electrons during transport before emission into vacuum. We also demonstrate a cathode cooling method that largely preserves the QE while reducing MTE, allowing us to achieve MTEs as low as 58 meV with 3% QE in green light from Cs 3 Sb photocathodes. Our results are crucial for producing brighter electron beams for various photoinjector applications like ultrafast electron diffraction and microscopy, x-ray free-electron lasers, and particle colliders.

36 MATERIALS SCIENCE↗
DOE OSTI2023

High Resolution Polar Kerr Effect Studies of CsV 3 Sb 5 : Tests for Time-Reversal Symmetry Breaking below the Charge-Order Transition

We report high resolution polar Kerr effect measurements on CsV 3 Sb 5 single crystals in search for signatures of spontaneous time reversal symmetry breaking below the charge order transition at T * = 94 K. Utilizing two different versions of zero-area loop Sagnac interferometers operating at 1550 nm wavelength, each with the fundamental attribute that without a time reversal symmetry breaking sample at its path, the interferometer is perfectly reciprocal, we find no observable Kerr effect to within the noise floor limit of the apparatus at 30 nanoradians. Simultaneous coherent reflection ratio measurements confirm the sharpness of the charge order transition in the same optical volume as the Kerr measurements. At finite magnetic field we observe a sharp onset of a diamagnetic shift in the Kerr signal at T *, which persists down to the lowest temperature without change in trend. Since 1550 nm is an energy that was shown to capture all features of the optical properties of the material that interact with the charge order transition, we are led to conclude that it is highly unlikely that time reversal symmetry is broken in the charge ordered state in CsV 3 Sb 5 .

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2022

Development of Cr, Se, U, Sb, and Te isotopes as indicators of redox reactions, contaminant fate, and contaminant transport in aqueous systems: A review

Cr, Se, U, Sb, and Te are toxic, redox-active elements that are more mobile and environmentally problematic in their oxidized forms, and less mobile and bioavailable in their reduced forms. This chapter reviews the development of Cr, Se, U, Sb, and Te isotope ratio measurements as new indicators of redox reactions and contaminant migration. Reliable analytical methods exist, but are still evolving. Understanding of isotopic fractionation induced by various (bio)geochemical processes has been explored in dozens of publications, yet is far from complete: Reduction reactions, the major driver of isotopic variation, have been relatively well studied. However, the magnitude of fractionation is variable and the systematics of that variation are still being explored. Isotopic fractionation induced by oxidation reactions is not well understood. Non-redox reactions, which involve smaller changes in bonding of these elements, tend to induce less isotopic fractionation, but can nonetheless cause significant isotopic shifts. Field applications of Cr, Se, U isotope ratios have demonstrated that they are useful as indicators of reduction in natural systems. A few studies suggest they are also useful as indicators of oxidation and contaminant sources. The physical and chemical complexity of groundwater systems hinders accurate quantitative interpretation of Cr, Se, U isotope data using simple models. Numerical models have been developed that capture the behavior of complex, coupled systems and enable the most effective extraction of information from field data sets.

58 GEOSCIENCES↗
DOE OSTI2026

Forming Gas Annealing Improves the Performance of Ex Situ Sb-Doped CdSeTe Thin-Film Solar Cells

Group V doping in cadmium-selenide-telluride (CdSeTe) polycrystalline thin-film solar cells has demonstrated improved power conversion efficiencies (PCEs) and long-term stabilities as compared to the traditional Cu doping in the last decade. The dopants can be successfully incorporated by either in situ or ex situ doping. Here, we report that forming gas (FG) annealing enhances the efficiencies of CdSeTe polycrystalline thin-film solar cells utilizing ex situ antimony (Sb) doping via close-space sublimation of SbCl3 at ambient pressure. The FG annealing increases the hole density and carrier lifetime, reduces the back barrier height, and, therefore, leads to improved open-circuit voltages (VOCs) and fill factors (FFs). The champion device achieves a PCE of 19.2% with a VOC of 877 mV, a current density (JSC) of 30.2 mA/cm2, and an FF of 72.4%. Importantly, the Sb-doped devices showed improved stability under stress tests as compared to Cu-doped devices.

14 SOLAR ENERGY↗
DOE OSTI2021

Compromise between band structure and phonon scattering in efficient n-Mg 3 Sb 2-x Bi x thermoelectrics

n-type Mg 3 Sb 2 -based materials have become a top candidate for efficient thermoelectric applications within 300–700 K, due to its high band degeneracy, inherently high carrier mobility and low lattice thermal conductivity, as well as its advantages of less toxicity and abundance. Existing works showed that Mg 3 Bi 2 -alloying largely help ensure the exceptional performance, leaving a key issue to be uncovered on the primary mechanisms favoring or limiting the thermoelectric performance of Mg 3 Sb 2-x Bi x alloys. Furthermore we focus on the alloy composition dependent transport properties at various temperatures, with a large volume of experimental data. It is revealed that, with increasing x, the reduction in both inertial mass and lattice thermal conductivity is significantly beneficial, but the closure in band gap leads to a strong compensation due to the bipolar effect. Such a compromise between band structure and phonon scattering results in optimal Mg 3 Bi 2 -alloying concentrations to be about 50%–75% at 300 K, 50%–60% at 450 K and 50% at 600 K, which successfully guiding this work to realize extraordinary thermoelectric figure of merit at these temperatures.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Electronic and thermal properties of the phase-change memory material, Ge 2 Sb 2 Te 5 , and results from spatially resolved transport calculations

Here, we report new insights into the electronic, structural, and transport (heat and charge) properties of the phase-change memory material amorphous Ge 2 Sb 2 Te 5 . Using realistic structural models of Konstantinou et al., (2019), we analyze the topology, electronic states, and lattice dynamics with density functional methods, including hybrid-functional calculations and machine-learned interatomic potentials. The Kohn–Sham orbitals near the Fermi level display a strong electron–phonon coupling, and exhibit large energy fluctuations at room temperature. The conduction tail states exhibit larger phonon-induced fluctuations than the valence tail states. To resolve transport at the atomic scale, we employ space-projected electronic conductivity and site-projected thermal conductivity methods. Local analysis of heat transport highlights the role of filamentary networks dominated by Te, with Sb and Ge making progressively smaller contributions.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2026

Anisotropic Ferromagnetism in CrAu 3 Sb 6

The crystal structure and properties of CrAu 3 Sb 6 are presented, determined by measurements on single crystal and polycrystalline samples and first-principles calculations. The trigonal structure (space group P$\overline{3}$1m) comprises a CdI 2 -like sublattice of AuSb 2 with Cr occupying octahedral holes in a fully ordered triangular array. It can be viewed as a variation of the interesting and well-known families of partially intercalated transition metal dichalcogenides, but with stronger interactions along the stacking direction evidenced by short Cr–Au distances. The compound is metallic and ferromagnetic with a Curie temperature of 164 K. A strong anomalous contribution to the Hall effect is seen in the ferromagnetic state, and quantum oscillations are observed in magnetization at 2 K. Magnetization measurements show that the ordered moments of 1.5 μ B per Cr are oriented along the c-axis with relatively strong magnetocrystalline anisotropy. Electronic structure calculations confirm this uniaxial anisotropy and the important role of spin–orbit coupling in CrAu 3 Sb 6 and reveal strongly favored ferromagnetic ground state consistent with the measured Curie temperature. Through combined experiment and theory, this work provides a detailed picture of the basic properties and behaviors of this uniquely structured, Cr-based, anisotropic ferromagnet.

Crystal structure↗
DOE OSTI2021

H-Atom Assignment and Sb–O Bonding of [Mes 3 SbOH][O 3 SPh] Confirmed by Neutron Diffraction, Multipole Modeling, and Hirshfeld Atom Refinement

Neutron wavelength-resolved Laue diffraction experiments permit accurate refinement of the H-atom positions and anisotropic displacement parameters of [Mes 3 SbOH][O 3 SPh]. A multipole-based charge density refinement and a topological analysis of the refined electron density were also performed. Hirshfeld atom refinement (HAR) recovers the neutron-determined H-atom parameters, and the quantum-mechanical electron density used in HAR recovers the electron density topology from the refined multipole model. We report these results confirm that [Mes 3 SbOH][O 3 SPh] does indeed feature a hydroxystibonium cation with a nominal Sb–O single bond and not a stibine oxide with an Sb=O/Sb + –O – bond.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Investigating Cu-Site Doped Cu–Sb–S Nanoparticles Using Photoelectron and Electron Paramagnetic Resonance Spectroscopy

Tetrahedrite (Cu 12 Sb 4 S 13 ) and famatinite (Cu 3 SbS 4 ) are good candidates for green energy applications because they possess promising thermoelectric and photovoltaic properties as well as contain earth-abundant and nontoxic constituents. Herein, X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and electron paramagnetic resonance spectroscopy (EPR) methods examined inherent electronic properties and interatomic magnetic interactions of Cu-site doped tetrahedrite and famatinite nanomaterials. An energy-efficient modified polyol method was utilized for the synthesis of tetrahedrite and famatinite nanoparticles doped on the Cu-site with Zn, Fe, Ni, Mn, and Co. This is the first parallel study of tetrahedrite and famatinite nanomaterials with XPS, UPS, and EPR methods alongside a systematic analysis of dopant-dependent effects on the electronic structure and magnetic interactions for each material. XPS showed that the Cu and Sb species in tetrahedrite and famatinite possess different oxidation states, while UPS characterization reveals larger dopant-dependent shifts in the work function for tetrahedrite nanoparticles (4.21 to 4.79 eV) than for famatinite nanoparticles (4.57 to 4.77 eV). Finally, all famatinite nanoparticles display an EPR signal, indicating trace amounts of paramagnetic Cu(II) present below the detection limit of XPS. For tetrahedrite, EPR signatures were observed only for the Zn-doped and Mn-doped nanoparticles, suggesting signal broadening from Cu–Cu spin exchange or spin–lattice relaxation. This study demonstrates the complementary nature of XPS and EPR techniques for studying the oxidation states of metals in solid-state nanomaterials. Comparing the electronic and magnetic properties of tetrahedrite and famatinite while studying the impact of dopant incorporation will guide future endeavors in designing sustainable, high-performance materials for renewable energy applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Robust Spin-Moiré-Superlattice-Driven Gap Opening in EuAg 4 Sb 2 under in-Plane Magnetic Field

Moiré superlattices introduce new length and energy scales, enabling discoveries, such as unconventional superconductivity, in 2D systems. This concept has recently been extended to bulk materials with multiple-q spin textures, opening exciting opportunities for spin moiré physics. A notable example is EuAg 4 S b2 , where a spin moiré superlattice (SMS), manifested as a double-q spin modulation, induces a superzone gap opening. In this work, we investigate the tunability of this gap by an in-plane magnetic field in EuAg 4 Sb 2 by using neutron scattering, magnetization, and transport measurements. We reveal a cycloidal ground state and multiple spin-reoriented phases induced by the in-plane field, highlighting the critical role of in-plane components in driving magnetic transitions. Moreover, we demonstrate that a robust gap opening persists in the double-q phase, regardless of in-plane field orientation. Model calculations attribute this robustness to the stability of the SMS under tilted fields. Here, our results establish EuAg 4 Sb 2 as a tunable platform for exploring the spin-texture-driven superzone gap opening in electronic states.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Rh → Sb Interactions Supported by Tris(8-quinolyl)antimony Ligands

The study of ambiphilic systems combining L-type and Z-type ligands within the same construct has emerged as a field of active investigation, especially in the cases of ligands containing a group 13 element as a σ-acceptor for transition metals. (1) Parallel to these developments, several groups have investigated more atypical systems in which the Z-type ligand is a group 15 element. (2) Our contributions to this area have focused on the use of phosphinostibine ligands for the generation of transition metal complexes in which the antimony moiety acts as a Z-type ligand. (1d,3) We have shown that the magnitude of the resulting M → Sb interaction can be readily modulated by the oxidation state of the antimony atom (4) as well as its charge which can be manipulated by abstraction of anionic ligands. (5) Our work has also shown that these effects can be leveraged to enhance the catalytic properties of the transition metal center. (4,5) Some of the simplest systems that we have investigated are those resulting from the reaction of platinum dichloride with the bis- or tris-phosphinostibines ClSb(o-dppp) 2 and Sb(o-dppp) 3 , respectively (o-dppp = o-(Ph 2 P)C 6 H 4 ). These reactions proceed by oxidative insertion of the stibine into a Pt- Cl bond to produce complexes A and B, (6) respectively (Chart 1). Reasoning that the properties of these complexes may also be influenced by the nature of the L-type buttresses, we have now questioned whether stibines featuring nitrogen donor ligands could also display the redox noninnocence of their phosphine counterparts and support the formation of such complexes. Following up on some of our work with ambiphilic tellurium-quinoline ligands, (7) we now report on the reaction of tris-(8-quinolyl)stibines (8) toward (MeCN) 3 RhCl 3 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Uniform Diffusion of Cooper Pairing Mediated by Hole Carriers in Topological Sb 2 Te 3 /Nb

Spin-helical Dirac Fermions at a doped topological insulator’s boundaries can support Majorana quasiparticles when coupled with s-wave superconductors, but in n-doped systems, the requisite induced Cooper pairing in topological states is often buried at heterointerfaces or complicated by degenerate coupling with bulk conduction carriers. Rarely probed are p-doped topological structures with nondegenerate Dirac and bulk valence bands at the Fermi level, which may foster long-range superconductivity without sacrificing Majorana physics. Using ultrahigh-resolution photoemission, we report proximity pairing with a large decay length in p-doped topological Sb 2 Te 3 on superconducting Nb. Despite no momentum-space degeneracy, the topological and bulk states of Sb 2 Te 3 /Nb exhibit the same isotropic superconducting gaps at low temperatures. Furthermore, our results unify principles for realizing accessible pairing in Dirac Fermions relevant to topological superconductivity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Transient Triplet Metallopnictinidenes M–Pn (M = Pd II , Pt II ; Pn = P, As, Sb): Characterization and Dimerization

Nitrenes (R–N) have been subject to a large body of experimental and theoretical studies. The fundamental reactivity of this important class of transient intermediates has been attributed to their electronic structures, particularly the accessibility of triplet vs singlet states. In contrast, electronic structure trends along the heavier pnictinidene analogues (R–Pn; Pn = P–Bi) are much less systematically explored. We here report the synthesis of a series of metallodipnictenes, {M–Pn=Pn–M} (M = Pd II , Pt II ; Pn = P, As, Sb, Bi) and the characterization of the transient metallopnictinidene intermediates, {M–Pn} for Pn = P, As, Sb. Structural, spectroscopic, and computational analysis revealed spin triplet ground states for the metallopnictinidenes with characteristic electronic structure trends along the series. In comparison to the nitrene, the heavier pnictinidenes exhibit lower-lying ground state SOMOs and singlet excited states, thus suggesting increased electrophilic reactivity. Furthermore, the splitting of the triplet magnetic microstates is beyond the phosphinidenes {M–P} dominated by heavy pnictogen atom induced spin–orbit coupling.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗