Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “coordinates”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,585 records · Page 88
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

High-power Mg batteries enabled by heterogeneous enolization redox chemistry and weakly coordinating electrolytes

Magnesium batteries have long been pursued as potentially low-cost, high-energy and safe alternatives to Li-ion batteries. However, Mg 2+ interacts strongly with electrolyte solutions and cathode materials, leading to sluggish ion dissociation and diffusion, and consequently low power output. Here we report a heterogeneous enolization chemistry involving carbonyl reduction (C=O ↔ C–O-), which bypasses the dissociation and diffusion difficulties, enabling fast and reversible redox processes. This kinetically favoured cathode is coupled with a tailored, weakly coordinating boron cluster-based electrolyte that allows for dendrite-free Mg plating/stripping at a current density of 20 mA cm -2 . The combination affords a Mg battery that delivers a specific power of up to 30.4 kW kg -1 , nearly two orders of magnitude higher than that of state-of-the-art Mg batteries. Here, the cathode and electrolyte chemistries elucidated here propel the development of magnesium batteries and would accelerate the adoption of this low-cost and safe battery technology.

25 ENERGY STORAGE↗
DOE OSTI2019

Reversible coordinative binding and separation of sulfur dioxide in a robust metal–organic framework with open copper sites

Emissions of SO 2 from flue gas and marine transport have detrimental impacts on the environment and human health, but SO 2 is also an important industrial feedstock if it can be recovered, stored and transported efficiently. In this paper, we report the exceptional adsorption and separation of SO 2 in a porous material, [Cu 2 (L)] (H 4 L = 4',4'''-(pyridine-3,5-diyl)bis([1,1'-biphenyl]-3,5-dicarboxylic acid)), MFM-170. MFM-170 exhibits fully reversible SO 2 uptake of 17.5 mmol g -1 at 298 K and 1.0 bar, and the SO 2 binding domains for trapped molecules within MFM-170 have been determined. We report the reversible coordination of SO 2 to open Cu(II) sites, which contributes to excellent adsorption thermodynamics and selectivities for SO 2 binding and facile regeneration of MFM-170 after desorption. MFM-170 is stable to water, acid and base and shows great promise for the dynamic separation of SO 2 from simulated flue gas mixtures, as confirmed by breakthrough experiments.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Gut microbiome partially mediates and coordinates the effects of genetics on anxiety-like behavior in Collaborative Cross mice

Abstract Growing evidence suggests that the gut microbiome (GM) plays a critical role in health and disease. However, the contribution of GM to psychiatric disorders, especially anxiety, remains unclear. We used the Collaborative Cross (CC) mouse population-based model to identify anxiety associated host genetic and GM factors. Anxiety-like behavior of 445 mice across 30 CC strains was measured using the light/dark box assay and documented by video. A custom tracking system was developed to quantify seven anxiety-related phenotypes based on video. Mice were assigned to a low or high anxiety group by consensus clustering using seven anxiety-related phenotypes. Genome-wide association analysis (GWAS) identified 141 genes (264 SNPs) significantly enriched for anxiety and depression related functions. In the same CC cohort, we measured GM composition and identified five families that differ between high and low anxiety mice. Anxiety level was predicted with 79% accuracy and an AUC of 0.81. Mediation analyses revealed that the genetic contribution to anxiety was partially mediated by the GM. Our findings indicate that GM partially mediates and coordinates the effects of genetics on anxiety.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2012

Structural design principles for self-assembled coordination polygons and polyhedra

We reviewed strategies for the design of ligands that combine with metal ions to form high-symmetry coordination assemblies. Evaluation of crystal structure evidence reveals that prior design approaches, based on the concept of complementary bonding vector angles, fail to predict the majority of known examples. After explaining the reasons for this failure, we show how an alternative approach, de novo structure-based design, provides a practical method that predicts a much wider range of component shapes encoded to direct the formation of such assemblies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Synthetic, structural, and luminescence study of uranyl coordination polymers containing chelating terpyridine and trispyridyltriazine ligands

In this work, seven uranyl coordination polymers [(UO 2 )(BrC 8 H 3 O 4 )(C 15 H 11 N 3 )] ( 1 ), [(UO 2 )(ClC 8 H 3 O 4 )(C 15 H 11 N 3 )] ( 2 ), [(UO 2 )(BrC 8 H 3 O 4 )(C 18 H 12 N 6 )]·H 2 O ( 3 ), [(UO 2 )(ClC 8 H 3 O 4 )(C 18 H 12 N 6 )]·2H 2 O ( 4 ), [(UO 2 )(C 8 H 3 IO 4 )(C 18 H 12 N 6 )]·2C 3 H 7 O ( 5 ), [(UO 2 )(C 9 H 6 O 4 )(C 18 H 12 N 6 )]·H 2 O ( 6 ), and [(UO 2 )(C 6 H 2 O 4 S)(C 18 H 12 N 6 )]·2H 2 O ( 7 ) containing N-donor ligands 2,2':6',2''-terpyridine (TPY) and 2,4,6-tripyridyl s-triazine (TPTZ); and O-donor linkers thiophene 2,5-dicarboxylic acid (TDC) and X-1,4-benzene dicarboxylic acid (X-BDC, where X = Me, Cl, Br, I) were synthesized and characterized using single crystal X-ray diffraction (SC-XRD), powder X-ray diffraction (PXRD), and fluorescence spectroscopy. Each compound crystallizes as binuclear pseudo dimers containing a UO 2 2+ pentagonal bipyramidal primary building unit. Fluorescence spectra of 1–4 , and 6–7 show characteristic UO 2 2+ emission whereas 5 is non-emissive. Red shifts within the emission of 1–4 are noted as a function of N-donor ligands TPY and TPTZ whereas emission shifts are not observed in TPTZ bearing compounds ( 3 , 4 , 6 , 7 ) containing different O-donor linkers. Luminescent lifetimes of 1–7 were obtained and fitted with either bi-exponential or tri-exponential components.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Coordination polymers of 5-substituted isophthalic acid

In this work, the synthesis and characterisation of five coordination polymers - Ni 2 (mip) 2 (H 2 O) 8 ·2H 2 O (1), Zn 6 (mip) 5 (OH) 2 (H 2 O) 4 ·7.4H 2 O (2), Zn 6 (mip) 5 (OH) 2 (H 2 O) 2 ·4H 2 O (3), Mn(HMeOip) 2 (4), and Mn 3 (tbip) 2 (Htbip) 2 (EtOH) 2 (5) - are reported. Preliminary nitric oxide release data on compounds 2 and 3 are also given.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Coordination chemistry of 2,2'-biphenylenedithiophosphinate and diphenyldithiophosphinate with U, Np, and Pu

New members of the dithiophosphinic acid family of potential actinide extractants were prepared: heterocyclic 2,2'-biphenylenedithiophosphinic acids of stoichiometry HS 2 P(R 2 C 12 H 6 ) (R = H or tBu). The time- and atom-efficient syntheses afforded multigram quantities of pure HS 2 P(R 2 C 12 H 6 ) in reasonable yields (~60%). These compounds differed from other diaryldithiophosphinic acid extractants in that the two aryl groups were connected to one another at the ortho positions to form a 5-membered dibenzophosphole ring. These 2,2'-biphenylenedithiophosphinic acids were readily deprotonated to form S 2 P(R 2 C 12 H 6 ) 1- anions, which were crystallized as salts with tetraphenylpnictonium cations (ZPh 4 1+ ; Z = P or As). Coordination chemistry between [S 2 P( t Bu 2 C 12 H 6 )] 1- and [S 2 P(C 6 H 5 )2] 1- with U, Np, and Pu was comparatively investigated. The results showed that dithiophosphinate complexes of UIV and NpIV were redox stable relative to those of UIII, whereas reactions involving PuIV gave intractable material. For instance, reactions involving UIV and NpIV generated An[S 2 P( t Bu 2 C 12 H 6 )] 4 and An[S 2 P(C 6 H 5 ) 2 ] 4 whereas reactions between PuIV and [S 2 P(C 6 H 5 ) 2 ] 1- generated a mixture of products from which we postulated a transient PuIII species based on UV-Vis spectroscopy. However, the trivalent Pu[S 2 P(C 6 H 5 ) 2 ] 3 (NC 5 H 5 ) 2 compound is stable and could be isolated from reactions between [S 2 P(C 6 H 5 ) 2 ] 1- and the trivalent PuI 3 (NC 5 H 5 ) 4 starting material. Attempts to synthesize analogous trivalent compounds with UIII provided the tetravalent U[S 2 P(C 6 H 5 )2 ] 4 oxidation product.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Surprising coordination for low-valent actinides resembling uranyl( VI ) in thorium( IV ) organic hybrid layered and framework structures based on a graphene-like (6,3) sheet topology

Three thorium(IV)-based metal–organic hybrid compounds with 2D layered and 3D framework structures exhibiting graphene-like (6,3) sheet topologies were prepared with linkers with threefold symmetry. Here, these compounds contain rare and relatively anisotropic coordination environments for low-valent actinides that are similar to those often observed for high-valent actinide ions.

Li, Yuxiang↗
DOE OSTI2016

CO 2 adsorption-induced structural changes in coordination polymer ligands elucidated via molecular simulations and experiments

Aiming to elucidate guest-induced structural changes in the coordination polymer CPL-2, grand canonical Monte Carlo (GCMC) simulations were used to predict CO 2 loadings in this material, and the results were compared with experimental isotherms. Our calculations suggest that CPL-2 exhibits more pronounced CO 2 -induced structural changes than previously reported. As the initial evidence, the isotherm simulated in the previously reported CPL-2 structure (experimentally resolved from X-ray diffraction in the “as-synthesized” CPL-2) underestimated the measured CO 2 loadings at high pressure, indicating that CPL-2 might undergo structural changes that enable higher pore volumes at high pressure. GCMC simulations in CPL-2 structures considering moderate unit cell expansions reported in the literature still underestimated high-pressure experimental loadings. However, considering an incremental rotation of the CPL-2 bipyridyl pillars with increasing CO 2 pressure, we were able to trace the measured isotherm with the simulation data. Computational analysis shows that ligand rotation in CPL-2 enables higher pore volumes, which, in turn, accommodate more CO 2 as the gas pressure increases. Desorption measurements suggest that hysteresis in the CO 2 isotherm of CPL-2 may also be linked to ligand rotation, and the measured adsorption/desorption cycles show that the rotation is reversible. Based on our simulations for CPL-4 and CPL-5 and previously reported experimental data, it is likely that these materials, which differ from CPL-2 in the bipyridyl ligand, behave similarly in the presence of CO 2 . Our results help understand the behavior of these materials, which present the kind of structural changes that could be potentially exploited to enhance the CO 2 working capacity of ultra-microporous materials for carbon capture applications.

Meza-Morales, Paul J.↗
DOE OSTI2017

Capping the calix: How toluene completes cesium( i ) coordination with calix[4]pyrrole

The role of solvent in molecular recognition systems is under-researched and often ignored, especially when the solvent is considered “non-interacting”. This study concerns the role of toluene solvent in cesium(I) recognition by calix[4]pyrrole. We show that π-donor interactions bind toluene molecules onto the open face of the cation-receptor complex, thus “capping the calix.” As a result, by characterizing this unusual aromatically-saturated complex, we show how “non-interacting” aromatic solvents can directly coordinate receptor-bound cations and thus influence recognition.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Intermediate temperature fuel cells via an ion-pair coordinated polymer electrolyte

Fuel cells are attractive devices that convert chemical energy into electricity through the direct electrochemical reaction of hydrogen and oxygen. Intermediate temperature fuel cells operated at 200–300°C can simplify water and thermal managements, enable the use of non-precious or low-loading precious metal catalysts and provide insensitivity toward fuel and air impurities such as carbon monoxide. However, the performance of current intermediate temperature fuel cells is poor due to a lack of highly-conductive membrane electrolytes and optimal electrodes designed for these fuel cells. We demonstrate high-performing intermediate temperature fuel cells that use SnP 2 O 7 –polymer composite membranes and a quaternary ammonium-biphosphate ion-pair coordinated polymer electrolyte in the electrodes. The peak power density of the fuel cell under H 2 and O 2 reached 870 mW cm -2 at 240°C with minimal performance loss under exposure to 25% carbon monoxide.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2018

A robust two-dimensional zirconium-based luminescent coordination polymer built on a V-shaped dicarboxylate ligand for vapor phase sensing of volatile organic compounds

Here we report herein a new two-dimensional zirconium-based luminescent coordination polymer Zr 6 (sdba) 4 (μ 3 -O) 4 (μ 3 - OH) 4 (HCOO) 2 (OH) 2 (H 2 O) 2 (1) [sdba = 4,4'-sulfonyldibenzoate] exhibiting selective fluorescence responses towards a variety of volatile organic compounds upon exposure in the vapor phase. Having a unique two-dimensional signal response towards aromatic molecules, including but not limited to nitroaromatic explosives, it is capable of identification of a diverse set of analytes. In addition, compound 1 shows a remarkably high sensitivity toward acetone vapors.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Uranyl dication mediated photoswitching of a calix[4]pyrrole-based metal coordination cage

A set of self-assembled tri- and tetrapodal metal coordination cage structures ( cage-1 and cage-2 , respectively) constructed from the uranyl dication (UO 2 2+ ) and a dibenzoic acid functionalised cis -calix[4]pyrrole ( 1 ) are described. The inherent photochemical reactivity of the uranyl dication mediates the transformation of cage-1 to cage-2 via the activation of molecular oxygen here.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗