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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on MoC4IO4 by Materials Project

MoI(CO)4 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of sixteen formaldehyde molecules and two MoI clusters. In one of the MoI clusters, Mo6+ is bonded in a distorted water-like geometry to two equivalent I1- atoms. There are one shorter (2.89 Å) and one longer (2.90 Å) Mo–I bond lengths. I1- is bonded in a 4-coordinate geometry to two equivalent Mo6+ atoms. In one of the MoI clusters, Mo6+ is bonded in a distorted water-like geometry to two equivalent I1- atoms. Both Mo–I bond lengths are 2.89 Å. I1- is bonded in a 2-coordinate geometry to two equivalent Mo6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nd2H13(CO)12 by Materials Project

NdH4(CO)3NdH3(CO)4(CO)5(H2)3 crystallizes in the monoclinic Pc space group. The structure is zero-dimensional and consists of ten formaldehyde molecules, eight hydrogen molecules, two NdH3(CO)4 clusters, and two NdH4(CO)3 clusters. In each NdH3(CO)4 cluster, Nd3+ is bonded in a 5-coordinate geometry to three H1+ and four O2- atoms. There are a spread of Nd–H bond distances ranging from 2.21–2.79 Å. There are a spread of Nd–O bond distances ranging from 2.34–2.36 Å. There are four inequivalent C+0.42+ sites. In the first C+0.42+ site, C+0.42+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.26 Å. In the second C+0.42+ site, C+0.42+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.26 Å. In the third C+0.42+ site, C+0.42+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.26 Å. In the fourth C+0.42+ site, C+0.42+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.26 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one Nd3+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one Nd3+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one Nd3+ atom. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nd3+ and one C+0.42+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nd3+ and one C+0.42+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Nd3+ and one C+0.42+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nd3+ and one C+0.42+ atom. In each NdH4(CO)3 cluster, Nd3+ is bonded in a 4-coordinate geometry to four H1+ and three O2- atoms. There are a spread of Nd–H bond distances ranging from 2.12–2.63 Å. There are a spread of Nd–O bond distances ranging from 2.30–2.33 Å. There are three inequivalent C+0.42+ sites. In the first C+0.42+ site, C+0.42+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.26 Å. In the second C+0.42+ site, C+0.42+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.26 Å. In the third C+0.42+ site, C+0.42+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.27 Å. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one Nd3+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one Nd3+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one Nd3+ atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one Nd3+ atom. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one Nd3+ and one C+0.42+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Nd3+ and one C+0.42+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Nd3+ and one C+0.42+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Dust and Ions: Self Organization and Stability (Final Report)

This project explores the stability and structure of systems with non-reciprocal interactions, challenging the traditional understanding based on Newton's third law, which states that every action has an equal and opposite reaction. Reciprocal forces are fundamental to the stability of systems ranging in size from atomic nuclei to galactic clusters. Our research investigates what happens when the forces between two objects are not equal and opposite. We used dusty plasmas as a model system to study non-reciprocal interactions. In a plasma chamber, micron-sized dust particles acquire a negative charge and form 2D planar "dust crystals" when levitated by the electric field present in the plasma sheath at the interface between the plasma and the lower surface of the chamber. This electric field also drives a vertical ion flow, creating a positively charged "plasma wake" downstream of the dust grains. While horizontally aligned dust grains interact reciprocally, a slight vertical displacement causes non-reciprocal interactions due to the attraction of the lower dust grain to the upper dust grain’s ion wake. Our experiments investigated the range of plasma conditions (gas pressure and system power) where stable dusty plasma structures are able to self-organize, aided by the ion wake. We studied systems ranging from pairs of dust particles to large 2D crystals, providing insights into the conditions that lead to stable or unstable structures. We used numerical simulations to investigate how ion wakes changed in response to changes in the operating conditions as well as how the wakes of separate grains interact when dust grains are in close proximity.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2026

Co-Design of Charge Transport Superhighways to Connect Catalytic Sites in Soft Photoelectrochemical Systems

Efficient photon-to-electron-to-molecule conversion requires multi-length scale control over charge transport pathways, where electronic charges are delivered to catalytic sites under high mass transport flux. A fundamental question is how can we co-design charge transport pathways to promote efficient charge transfer to/from catalytic sites in complex three-dimensional architectures? Soft conducting polymer systems offer exceptional promise to provide three-dimensional charge transport networks, where electrolyte (ion and solvent) can interdiffuse to promote long-lived charge carriers and the molecular nature allows for strategic synthetic design of catalytic sites. Herein we combine theoretical and experimental approaches to investigate the earliest stages of photoelectrochemical deposition of near-surface catalytic sites (Pt) on soft bulk heterojunction polymeric semiconductors composed of a prototype donor (PTB7-Th) and a prototype acceptor (N2200) as a model system towards better understanding molecular catalyst-polymer site interactions. We focus initially on photoelectrochemical deposition of low Pt loadings, nanoparticle sizes (formed by progressive nucleation) below 20 nm, for both density functional theory (DFT) modeling studies and for spectroscopic characterization using surface-sensitive X-ray and UV-photoemission (XPS/UPS). DFT modeling of “n-type” N2200 slabs reveal for the first time that sulfur atoms in the thiophene units serve as the lowest-energy adsorption sites for single Pt atoms, while larger Pt clusters engage more complexly with both thiophene and naphthalene diimide (NDI) core sites. Changes in chemical composition observed by X-ray photoelectron spectroscopy (XPS) support the DFT predictions, and the angle-resolved measurements reveal that Pt nucleation initiates at subsurface sites which appear to be localized active domains that promote charge transport/transfer and enable vertical growth toward the surface. These results suggest that light-activated Pt nanoparticle deposition decorates energetically distinct sites, where photoactivity is dictated by the local energetics of those sites, and the fact that they represent the termini of charge transport “super-highways” – a small percentage of the total volume of the donor/acceptor polymeric active layer which carries most of the photocurrent generated during both Pt deposition and photoelectrochemical HER. We posit that these initial studies provide a foundational strategy for design of catalytic sites in the near surface regions of complex polymeric materials and advancing soft semiconductor-based photoelectrochemical systems. Achieving a nanometer-scale understanding of catalyst deposition and the impact of local composition and energetics on that placement, should ultimately provide the design guidelines (co-design) for a broad array of catalysts at sites that optimize that efficiency and maximize platform durability.

14 SOLAR ENERGY↗
NASA NTRS2004

Sensor for Monitoring Nanodevice-Fabrication Plasmas

The term plasma process diagnostics (PPD) refers to a spectroscopic technique and sensing hardware that have been proposed for monitoring plasma processes used to fabricate electronic devices that feature sizes as small as several nanometers. Nanometer dimensions are characteristic of the quantum level of miniaturization, where single impurity atoms or molecules can drastically change the local properties of the nanostructures. Such changes may be purposely used in nanoscale design but may also be extremely damaging or cause improper operation of the fabricated devices. Determination of temperature and densities of reactants near the developing features is important, since the structural synthesis is affected by characteristics of the local microenvironment. Consequently, sensors capable of nonintrusive monitoring with high sensitivity and high resolution are essential for real-time atomistic control of reaction kinetics and minimizing trace contamination in plasma processes used to fabricate electronic nanodevices. Such process-monitoring sensors are required to be compact, multiparametric, and immune to the harsh environments of processing plasmas. PPD is intended to satisfy these requirements. The specific technique used to implement plasma diagnostics with a PPD sensor would be an advanced version of continuous-wave cavity-ringdown spectroscopy (CW-CRDS) capable of profiling spectral line broadenings in order to derive both Doppler and Stark components. CRDS is based on measurements of the rate of absorption of laser light in an optical resonator. The ultimate sensitivity results from a very long absorption path length within the cavity and immunity to variations in incident laser intensity. The proposed version of this technique would involve the use of multiplexing tunable laser diodes and an actively modulated high-reflectivity optical resonator, thus offering a synergistic combination of simplicity, compactness, high sensitivity, and high resolution. The multiplexing capabilities of diode lasers could be utilized to make the PPD sensor a single, simple, compact, and inexpensive tool for the acquisition of multiparametric data. A PPD sensor would be capable of continuous measurement of such physical parameters as gas temperature, gas velocity, electron number density, and absolute densities of reacting chemical species. A laser beam can be easily adjusted to analyze the immediate vicinity of the growing nanostructures (or features etched down) in real time. The absorption enhancement in an optical cavity would afford the sensitivity needed for measurement of the temperature and densities of species at concentrations significantly lower than measurable by other nonintrusive techniques. It is anticipated that fully developed PPD sensors would enable simultaneous measurement of local temperature and determination of plasma species responsible for the synthesis and functionalization of nanodevices. These sensors would also enable tracking the pathways and origins of damaging contaminants, thereby providing feedback for adjustment of processes to optimize them and reduce contamination. The PPD sensors should also be useful for optimization of conventional microelectronics manufacturing plasma processes. Going beyond plasma processes for fabrication of electronic devices, PPD sensors could be used for monitoring of atoms, molecules, ions, radicals, clusters, and particles in a variety of other settings, including outer space. Because of their high sensitivity, such sensors could also prove useful for detecting traces of illegal drugs and explosives.

Bolshakov, Alexander↗
DOE OSTI2020

Materials Data on Mn2SnC9ClO9 by Materials Project

Mn(CO)5Mn(CO)4SnCl crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four tin chloride (sncl) molecules, four Mn(CO)4 clusters, and four Mn(CO)5 clusters. In each Mn(CO)4 cluster, Mn2+ is bonded in a rectangular see-saw-like geometry to four C+1.44+ atoms. There are a spread of Mn–C bond distances ranging from 1.81–1.87 Å. There are four inequivalent C+1.44+ sites. In the first C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.17 Å. In the third C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.17 Å. In the fourth C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In each Mn(CO)5 cluster, Mn2+ is bonded in a square pyramidal geometry to five C+1.44+ atoms. There are a spread of Mn–C bond distances ranging from 1.82–1.88 Å. There are five inequivalent C+1.44+ sites. In the first C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.15 Å. In the fourth C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.15 Å. In the fifth C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.15 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mn2SnC9BrO9 by Materials Project

Mn(CO)4Mn(CO)5SnBr crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four bromostannane molecules, four Mn(CO)4 clusters, and four Mn(CO)5 clusters. In each Mn(CO)4 cluster, Mn2+ is bonded in a rectangular see-saw-like geometry to four C+1.44+ atoms. There are a spread of Mn–C bond distances ranging from 1.79–1.87 Å. There are four inequivalent C+1.44+ sites. In the first C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.17 Å. In the third C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.17 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In each Mn(CO)5 cluster, Mn2+ is bonded in a square pyramidal geometry to five C+1.44+ atoms. There are a spread of Mn–C bond distances ranging from 1.84–1.88 Å. There are five inequivalent C+1.44+ sites. In the first C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the fifth C+1.44+ site, C+1.44+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.15 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one C+1.44+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C6S3(N3Cl)2 by Materials Project

CNS(CN)2CNSNCC(Cl2)NS crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four 1,2,4-thiadiazole molecules; four hydrogen cyanide molecules; four CNS clusters; and four NCC(Cl2)NS clusters. In each CNS cluster, C4+ is bonded in a distorted single-bond geometry to one S2- atom. The C–S bond length is 1.63 Å. N+2.67- is bonded in a single-bond geometry to one S2- atom. The N–S bond length is 1.53 Å. S2- is bonded in a 2-coordinate geometry to one C4+ and one N+2.67- atom. In each NCC(Cl2)NS cluster, there are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a bent 120 degrees geometry to one N+2.67- and one Cl1- atom. The C–N bond length is 1.29 Å. The C–Cl bond length is 1.74 Å. In the second C4+ site, C4+ is bonded in a bent 120 degrees geometry to one N+2.67- and one Cl1- atom. The C–N bond length is 1.30 Å. The C–Cl bond length is 1.78 Å. There are two inequivalent N+2.67- sites. In the first N+2.67- site, N+2.67- is bonded in a bent 120 degrees geometry to one C4+ and one S2- atom. The N–S bond length is 1.63 Å. In the second N+2.67- site, N+2.67- is bonded in a bent 120 degrees geometry to one C4+ and one S2- atom. The N–S bond length is 1.64 Å. S2- is bonded in a distorted water-like geometry to two N+2.67- atoms. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one C4+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe4Ge(CO)16 by Materials Project

(Fe(CO)4)4Ge crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four germanium molecules and sixteen Fe(CO)4 clusters. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.77–1.82 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.77–1.81 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In eight of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There is two shorter (1.79 Å) and two longer (1.82 Å) Fe–C bond length. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe4Si(CO)16 by Materials Project

(Fe(CO)4)4Si crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four silicon molecules and sixteen Fe(CO)4 clusters. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.77–1.81 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.76–1.82 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In eight of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There is one shorter (1.77 Å) and three longer (1.80 Å) Fe–C bond length. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Catalytic, Spectroscopic, and Theoretical Studies of Fe 4 S 4 -Based Coordination Polymers as Heterogenous Coupled Proton–Electron Transfer Mediators for Electrocatalysis

Iron–sulfur clusters play essential roles in biological systems, and thus synthetic [Fe 4 S 4 ] clusters have been an area of active research. Recent studies have demonstrated that soluble [Fe 4 S 4 ] clusters can serve as net H atom transfer mediators, improving the activity and selectivity of a homogeneous Mn CO 2 reduction catalyst. Here, in this work, we demonstrate that incorporating these [Fe 4 S 4 ] clusters into a coordination polymer enables heterogeneous H atom transfer from an electrode surface to a Mn complex dissolved in solution. A previously reported solution-processable Fe 4 S 4 -based coordination polymer was successfully deposited on the surfaces of different electrodes. The coated electrodes serve as H atom transfer mediators to a soluble Mn CO 2 reduction catalyst displaying good product selectivity for formic acid. Furthermore, these electrodes are recyclable with a minimal decrease in activity after multiple catalytic cycles. The heterogenization of the mediator also enables the characterization of solution-phase and electrode surface species separately. Surface enhanced infrared absorption spectroscopy (SEIRAS) reveals spectroscopic signatures for an in situ generated active Mn–H species, providing a more complete mechanistic picture for this system. The active species, reaction mechanism, and the protonation sites on the [Fe 4 S 4 ] clusters were further confirmed by density functional theory calculations. The observed H atom transfer reactivity of these coordination polymer-coated electrodes motivates additional applications of this composite material in reductive H atom transfer electrocatalysis.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on H14RhC6NClO4 by Materials Project

RhC4NH8O4Cl(CH3)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of eight methane molecules and two RhC4NH8O4Cl clusters. In one of the RhC4NH8O4Cl clusters, Rh4+ is bonded in a distorted square pyramidal geometry to four O2- and one Cl1- atom. There are two shorter (2.07 Å) and two longer (2.08 Å) Rh–O bond lengths. The Rh–Cl bond length is 2.61 Å. There are four inequivalent C1- sites. In the first C1- site, C1- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.48 Å. There is one shorter (1.09 Å) and two longer (1.10 Å) C–H bond length. In the second C1- site, C1- is bonded in a distorted bent 120 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.28 Å. In the third C1- site, C1- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.48 Å. All C–H bond lengths are 1.09 Å. In the fourth C1- site, C1- is bonded in a distorted bent 120 degrees geometry to two O2- atoms. There is one shorter (1.28 Å) and one longer (1.29 Å) C–O bond length. N3- is bonded in a tetrahedral geometry to two C1- and two H1+ atoms. Both N–H bond lengths are 1.05 Å. There are eight inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- and one Cl1- atom. The H–Cl bond length is 2.10 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Rh4+ and one C1- atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Rh4+ and one C1- atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Rh4+ and one C1- atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Rh4+ and one C1- atom. Cl1- is bonded in a 2-coordinate geometry to one Rh4+ and one H1+ atom. In one of the RhC4NH8O4Cl clusters, Rh4+ is bonded in a distorted square pyramidal geometry to four O2- and one Cl1- atom. There are a spread of Rh–O bond distances ranging from 2.06–2.08 Å. The Rh–Cl bond length is 2.65 Å. There are four inequivalent C1- sites. In the first C1- site, C1- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.49 Å. There is one shorter (1.09 Å) and two longer (1.10 Å) C–H bond length. In the second C1- site, C1- is bonded to one N3- and three H1+ atoms to form corner-sharing CH3N tetrahedra. The C–N bond length is 1.49 Å. There is one shorter (1.09 Å) and two longer (1.10 Å) C–H bond length. In the third C1- site, C1- is bonded in a distorted bent 120 degrees geometry to two O2- atoms. There is one shorter (1.28 Å) and one longer (1.29 Å) C–O bond length. In the fourth C1- site, C1- is bonded in a distorted bent 120 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.28 Å. N3- is bonded in a distorted tetrahedral geometry to two C1- and two H1+ atoms. There is one shorter (1.04 Å) and one longer (1.06 Å) N–H bond length. There are eight inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one N3- and one Cl1- atom. The H–Cl bond length is 2.05 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C1- atom. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Rh4+ and one C1- atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Rh4+ and one C1- atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Rh4+ and one C1- atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Rh4+ and one C1- atom. Cl1- is bonded in a distorted L-shaped geometry to one Rh4+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Os5(CO)16 by Materials Project

(Os(CO)3)4Os(CO)4 crystallizes in the trigonal P3_121 space group. The structure is zero-dimensional and consists of twelve Os(CO)3 clusters and three Os(CO)4 clusters. In each Os(CO)3 cluster, Os+1.60- is bonded in a distorted T-shaped geometry to three C+2.50+ atoms. There is one shorter (1.89 Å) and two longer (1.90 Å) Os–C bond length. There are three inequivalent C+2.50+ sites. In the first C+2.50+ site, C+2.50+ is bonded in a linear geometry to one Os+1.60- and one O2- atom. The C–O bond length is 1.16 Å. In the second C+2.50+ site, C+2.50+ is bonded in a linear geometry to one Os+1.60- and one O2- atom. The C–O bond length is 1.16 Å. In the third C+2.50+ site, C+2.50+ is bonded in a linear geometry to one Os+1.60- and one O2- atom. The C–O bond length is 1.17 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+2.50+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+2.50+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+2.50+ atom. In each Os(CO)4 cluster, Os+1.60- is bonded in a see-saw-like geometry to four C+2.50+ atoms. There is two shorter (1.94 Å) and two longer (1.98 Å) Os–C bond length. There are two inequivalent C+2.50+ sites. In the first C+2.50+ site, C+2.50+ is bonded in a distorted single-bond geometry to one Os+1.60- and one O2- atom. The C–O bond length is 1.16 Å. In the second C+2.50+ site, C+2.50+ is bonded in a distorted linear geometry to one Os+1.60- and one O2- atom. The C–O bond length is 1.16 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+2.50+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+2.50+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PrH10N(ClO4)2 by Materials Project

PrH12(O3Cl)2PrN2H8(O5Cl)2 crystallizes in the monoclinic P2/c space group. The structure is zero-dimensional and consists of two PrH12(O3Cl)2 clusters and two PrN2H8(O5Cl)2 clusters. In each PrH12(O3Cl)2 cluster, Pr3+ is bonded in a 8-coordinate geometry to six O2- and two equivalent Cl1- atoms. There are two shorter (2.49 Å) and four longer (2.50 Å) Pr–O bond lengths. Both Pr–Cl bond lengths are 2.91 Å. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Pr3+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to one Pr3+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Pr3+ and two H1+ atoms. Cl1- is bonded in a 1-coordinate geometry to one Pr3+ atom. In each PrN2H8(O5Cl)2 cluster, Pr3+ is bonded in a 10-coordinate geometry to eight O2- and two equivalent Cl1- atoms. There are a spread of Pr–O bond distances ranging from 2.51–2.86 Å. Both Pr–Cl bond lengths are 2.92 Å. N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.26 Å) and one longer (1.28 Å) N–O bond length. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Pr3+ and two H1+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one N5+ atom. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Pr3+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one Pr3+ and one N5+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Pr3+ and one N5+ atom. Cl1- is bonded in a 2-coordinate geometry to one Pr3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeAg3H6(C3N4)2 by Materials Project

Fe(Ag(CN)3)2Ag(NH3)2 crystallizes in the monoclinic Cc space group. The structure is zero-dimensional and consists of four iron molecules, four Ag(CN)3 clusters, and four Ag(NH3)2 clusters. In each Ag(CN)3 cluster, there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded to four N3- atoms to form edge-sharing AgN4 tetrahedra. There are a spread of Ag–N bond distances ranging from 2.15–2.50 Å. In the second Ag1+ site, Ag1+ is bonded to four N3- atoms to form distorted edge-sharing AgN4 tetrahedra. There are a spread of Ag–N bond distances ranging from 2.17–2.54 Å. There are six inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.18 Å. In the second C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.18 Å. In the third C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.18 Å. In the fourth C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.18 Å. In the fifth C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.18 Å. In the sixth C2+ site, C2+ is bonded in a single-bond geometry to one N3- atom. The C–N bond length is 1.18 Å. There are six inequivalent N3- sites. In the first N3- site, N3- is bonded in a 3-coordinate geometry to two Ag1+ and one C2+ atom. In the second N3- site, N3- is bonded in a 1-coordinate geometry to two Ag1+ and one C2+ atom. In the third N3- site, N3- is bonded in a distorted linear geometry to one Ag1+ and one C2+ atom. In the fourth N3- site, N3- is bonded in a distorted bent 150 degrees geometry to one Ag1+ and one C2+ atom. In the fifth N3- site, N3- is bonded in a distorted linear geometry to one Ag1+ and one C2+ atom. In the sixth N3- site, N3- is bonded in a 2-coordinate geometry to one Ag1+ and one C2+ atom. In each Ag(NH3)2 cluster, Ag1+ is bonded in a distorted linear geometry to two N3- atoms. There are one shorter (2.13 Å) and one longer (2.17 Å) Ag–N bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and three H1+ atoms. All N–H bond lengths are 1.02 Å. In the second N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and three H1+ atoms. There is two shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Effect of Surface Temperature on the Distribution and Reactivity of Rh Active Sites for CO Oxidation

Single–atom catalysts are a fast–emerging area in which late–transition metal atoms are supported on oxides, metals, and carbonaceous supports. They show great promise for selective chemical reactions due to their well–defined active sites, and significantly reduce precious metal loading. However, oxide–supported single–atom catalysts have drawbacks such as deactivation due to sintering, and there are on–going debates about the exact nature of the active sites. Herein we report a model system where the surface temperature during Rh deposition on a copper oxide support dictates the Rh size distribution. Here our temperature–programmed desorption experiments reveal that Rh clusters perform CO oxidation at lower temperature than single atoms, and isotopic labelling demonstrates differences in the mechanism in that the C–O bond is broken and reformed on clusters, as opposed to a pure Mars van Krevelen mechanism for CO oxidation at the single–atom Rh sites. We further examine the cluster size distributions with scanning tunneling microscopy and X–ray photoelectron spectroscopy which confirm the presence of both clusters and single atoms for the lower temperature deposition and only single atoms for the higher temperature deposition. Together, these results provide a fundamental understanding of the differences in the CO oxidation mechanism on Rh atoms and clusters.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CoI2(N3O)2 by Materials Project

Co(NO)2CoI4(NO)2(N2)4 crystallizes in the monoclinic C2/m space group. The structure is zero-dimensional and consists of sixteen nitrogen molecules, two Co(NO)2 clusters, and four CoI4(NO)2 clusters. In each Co(NO)2 cluster, Co2+ is bonded in a 3-coordinate geometry to one N+0.67+ and two O2- atoms. The Co–N bond length is 1.86 Å. There are one shorter (2.08 Å) and one longer (2.10 Å) Co–O bond lengths. There are two inequivalent N+0.67+ sites. In the first N+0.67+ site, N+0.67+ is bonded in a distorted linear geometry to one Co2+ and one N+0.67+ atom. The N–N bond length is 1.15 Å. In the second N+0.67+ site, N+0.67+ is bonded in a water-like geometry to two O2- atoms. Both N–O bond lengths are 1.28 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in an L-shaped geometry to one Co2+ and one N+0.67+ atom. In the second O2- site, O2- is bonded in an L-shaped geometry to one Co2+ and one N+0.67+ atom. In each CoI4(NO)2 cluster, Co2+ is bonded in a distorted trigonal non-coplanar geometry to one N+0.67+ and two O2- atoms. The Co–N bond length is 1.77 Å. There are one shorter (2.06 Å) and one longer (2.11 Å) Co–O bond lengths. There are two inequivalent N+0.67+ sites. In the first N+0.67+ site, N+0.67+ is bonded in a distorted bent 150 degrees geometry to one Co2+ and one I1- atom. The N–I bond length is 1.94 Å. In the second N+0.67+ site, N+0.67+ is bonded in a water-like geometry to two O2- atoms. There is one shorter (1.27 Å) and one longer (1.29 Å) N–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted L-shaped geometry to one Co2+, one N+0.67+, and one I1- atom. The O–I bond length is 3.66 Å. In the second O2- site, O2- is bonded in an L-shaped geometry to one Co2+ and one N+0.67+ atom. There are four inequivalent I1- sites. In the first I1- site, I1- is bonded in a single-bond geometry to one N+0.67+ and one I1- atom. The I–I bond length is 2.85 Å. In the second I1- site, I1- is bonded in a single-bond geometry to one I1- atom. The I–I bond length is 2.68 Å. In the third I1- site, I1- is bonded in a single-bond geometry to one I1- atom. In the fourth I1- site, I1- is bonded in an L-shaped geometry to one O2- and one I1- atom.

36 MATERIALS SCIENCE↗
NASA NTRS1997

Optical and Atomic Force Microscopy Characterization of PbI2 Quantum Dots

Lead iodide (PbI2) clusters were synthesized from the chemical reaction of NaI (or KI) with Pb(NO3)2 in H2O, D2O, CH3OH, and C3H7OH media. The observation of the absorption features above 350 nm with the help of integrating sphere accessory strongly suggests the quantum dot formation of PbI2 in solution. Spectral comparison between the synthesized PbI2 clusters in solution and PbI2 nanophase by impregnation of PbI2 in four different pore-sized porous silica indicates that the PbI2 cluster size in solution is less than 2.5 nm in lateral dimension. Atomic force microscopy (AFM) measurements show that the PbL clusters deposited onto three different molecularly flat surfaces are single-layered. The measured height is 1.0 - 0.1 nm. The swollen layer thickness can be attributed to the intralayer contraction from the strong lateral interaction among PbI2 molecules, which is supported by ab initio calculation. Raman scattering measurement of LO and TO modes of PbI2 in bulk and in the confined state were also conducted in 50-150 cu cm region. The observed three bands at 74, %, 106 1/cm are assigned to TO2, LO2, and LO, mode, respectively. The relatively small red-shift in LO modes may be caused by the surface phonon polaritons of PbI2 nanophase in the porous silica.

Mu, R.↗