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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.
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A new way to overcome the phase-separation problem to fabricate 2D B–C–N via molecule-like carbon doping in 2D BN.
The stability of DOTA-chelated complexes coordinated with H 2 O has a strong correlation between the opening angle of DOTA and the atomic mass of the radioactive isotope.
Poly(cyclosilane)s, conjugated polymers inspired by crystalline silicon, are synthesized by group 4 metallocene-promoted dehydrocoupling polymerization.
Wettability of graphene is characterized from first principles.
Low-energy rattling of potassium cations in open channels of Mg–Sb framework causes a Phonon-Glass thermal behavior of novel antimonide KMg 4 Sb 3 .
Weakly-bound ligands in dynamic exchange expose the surface of CdSe quantum dots to pH-dependent modification.
Three novel zinc–porphyrin MOFs have been synthesized by using versatile N-containing ligands. The open Watson–Crick pair in the interior surface in one Zn-MOF has been presented, which could endow the related MOF with excellent selective adsorption of dye molecules.
Aliovalently Al 3+ doped strontium titanate enables overall water splitting in type 1 baggie particle suspension reactors in direct sunlight.
δ-MnO 2 transforms to α-MnO 2 through a multistage oriented assembly process which is induced by Mn( iii ).
Europium( iii ) dipicolinate complexes have been a model system in lanthanide solution chemistry for decades, here it is investigated in unprecedented detail.
(a) Cross-sectional TEM micrograph of 14 period InAs/GaSb SL, demonstrating abrupt interfaces; and (b) Shubnikov-de Haas oscillations testifying high mobility.
BaMn 3 Ti 4 O 14+δ ( δ = 0.25, BMT-134), a recently discovered single-phase multiferroic complex oxide was doped with varying concentrations of Fe in order to assess the effect on magnetic and dielectric behavior.
Neat alkoxythiophenes react with MOF HKUST-1 to form a core–shell composite where the HKUST-1 surface is coated with conjugated polymer, while hexane solutions of thiophenes form a filled composite with polythiophene inside MOF pores.
An unexpected blue shift in the characteristic uranyl ν1 stretching frequency is observed upon engagement of the uranyl oxo with isothiocyanate group stemming from coupling between UO and U-NCS modes.
Phosphinodiboranates (H 3 BPR 2 BH 3 – ) are a class of borohydrides that have merited a reputation as weakly coordinating anions, which is attributed in part to the dearth of coordination complexes known with transition metals, lanthanides, and actinides. We recently reported how K(H 3 BP t Bu 2 BH 3 ) exhibits sluggish salt elimination reactivity with f-metal halides in organic solvents such as Et 2 O and THF. Here we report how this reactivity appears to be further attenuated in solution when the t Bu groups attached to phosphorus are exchanged for R = Ph or H, and we describe how mechanochemistry was used to overcome limited solution reactivity with K(H 3 BPPh 2 BH 3 ). Grinding three equivalents of K(H 3 BPPh 2 BH 3 ) with UI 3 (THF) 4 or LnI 3 (Ln = Ce, Pr, Nd) allowed homoleptic complexes with the empirical formulas U(H 3 BPPh 2 BH 3 ) 3 (1), Ce(H 3 BPPh 2 BH 3 ) 3 (2), Pr(H 3 BPPh 2 BH 3 ) 3 (3), and Nd(H 3 BPPh 2 BH 3 ) 3 (4) to be prepared and subsequently crystallized in good yields (50–80%). Single-crystal XRD studies revealed that all four complexes exist as dimers or coordination polymers in the solid-state, whereas 1 H and 11 B NMR spectra showed that they exist as a mixture of monomers and dimers in solution. Treating 4 with THF breaks up the dimer to yield the monomeric complex Nd(H 3 BPPh 2 BH 3 ) 3 (THF) 3 (4-THF). XRD studies revealed that 4-THF has one chelating and two dangling H 3 BPPh 2 BH 3 – ligands bound to the metal to accommodate binding of THF. In contrast to the results with K(H 3 BPPh 2 BH 3 ), attempting the same mechanochemical reactions with Na(H 3 BPH 2 BH 3 ) containing the simplest phosphinodiboranate were unsuccessful; only the partial metathesis product U(H 3 BPH 2 BH 3 )I 2 (THF) 3 (5) was isolated in poor yields. Here, despite these limitations, our results offer new examples showing how mechanochemistry can be used to rapidly synthesize molecular coordination complexes that are otherwise difficult to prepare using more traditional solution methods.
Hard stoichiometric WB 4 is synthesized under high-pressure and high-temperature conditions.
Exploring materials that simultaneously possess high conductivity and electrochemical stability is critical for various energy-conversion applications. In this study, our combined computations and experiments suggest the Mg–Ti–O chemical space for novel ternary oxide compounds offering high electrical conductivity and corrosion stability in acidic conditions to be potentially used as catalyst supporter of polymer electrolyte membrane fuel cells. High electrical conductivity (6.09 × 10 -1 S cm -1 ) is achieved at room temperature by tuning the chemical composition of Mg 1-x Ti 2+x O 5 while still maintaining good corrosion stability (1.2 × 10 -4 mA cm -2 after six days) in acidic conditions. Furthermore, we discover that a reducing gas environment during the synthesis increases the Ti solubility in Mg 1-x Ti 2+x O 5 with a reduced valence state of Ti, thus resulting in high conductivity.
BaTiO 3 nanocubes capped by polar tetrafluoroborate (BF 4 − ) ligands are shown to have enhanced ferroelectric order and undergo sharper ferroelectric to paraelectric phase transitions relative to nanocubes capped with nonpolar oleic acid (OA) ligands.