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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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At least 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Ternary gallides of the Ce{sub 2+n}Rh{sub 3+3n}Ga{sub 1+2n} (n = 0—5) structure family

The structures of nine ternary intermetallic compounds (IMCs) of the cerium—rhodium—gallium system containing 50 at.% rhodium were determined by single-crystal X-ray diffraction. The compounds are built up of alternating Ce{sub 2}Rh{sub 3}Ga fragments with the Mg{sub 2}Cu{sub 3}Si (MgZn{sub 2} type) or Mg{sub 2}Ni{sub 3}Si (MgCu{sub 2} type) structure and CeRh{sub 3}Ga{sub 2} fragments with the CeCo{sub 3}B{sub 2} (CaCu{sub 5} type) structure and form a homologous series of the composition R{sub 2+n}T{sub 3+3n}M{sub 1+2n} (n = 0—5). These compounds can be classified into trigonal (R-3m) or hexagonal (P6{sub 3}/mmc) branches depending on the Laves phase-type fragment.

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

Three-dimensional copper(II) carboxylates based on 4,4′,4″-benzene-1,3,5-triyltris(benzoic acid)

The homochiral coordination polymers [Cu{sub 4}(CH{sub 3}OH)(H{sub 2}O){sub 4}(Hbtb)(S-mal){sub 2}]•4H{sub 2}O and [Cu{sub 4}(CH{sub 3}OH)(H{sub 2}O){sub 4}(Hbtb)(R-mal){sub 2}]•4H{sub 2}O were synthesized by heating S- or R-malic acid (H{sub 3}mal), 4,4′,4″-benzene-1,3,5-triyltris(benzoic acid) (H{sub 3}btb), and copper(II) acetate in an aqueous methanolic solution. The reaction with copper(II) nitrate in aqueous dioxane afforded the coordination framework [Cu{sub 6}(C{sub 4}H{sub 8}O{sub 2}){sub 3}(H{sub 2}O){sub 3}(btb){sub 4}]•4C{sub 4}H{sub 8}O{sub 2}•10H{sub 2}O, which does not contain chiral ligands. The compositions and crystal structures of the new compounds were determined by single-crystal X-ray diffraction and confirmed by X-ray powder diffraction, IR spectroscopy, thermogravimetric and elemental analysis.

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

Synthesis and crystal structure of the coordination polymer [{Li(H_2O)_3}{sub 2}(C{sub 36}H{sub 36}N{sub 24}O{sub 12})]Cl{sub 2}•6H{sub 2}O

The coordination polymer of the composition [{Li(H_2O)_3}{sub 2}(C{sub 36}H{sub 36}N{sub 24}O{sub 12})]Cl{sub 2}•6H{sub 2}O (1) was synthesized by heating an aqueous solution of lithium chloride and cucurbit[6]uril (CB[6]). According to single-crystal X-ray diffraction data, solvated lithium cations in compound 1 form coordination bonds with oxygen atoms of CB[6] molecules. Compound 1 was characterized by X-ray diffraction, IR spectroscopy, thermogravimetric and elemental analysis. Luminescence spectra of the new compound were measured.

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

Synthesis and structural features of new pentacoordinated monofluorosilanes containing C,O-chelate ligands based on 2-amino acid N-methylamides

Pentacoordinated monofluorosilanes R{sup 1}SO{sub 2}NHCHR{sub 2}C(O)N(Me)CH{sub 2}SiMe{sub 2}F containing moieties of N′-methyl-N-(organosulfonyl)-2-amino acid amides of glycine, alanine, and leucine as C,O-chelating ligands were synthesized via the reaction of corresponding disiloxanes with BF{sub 3}•Et{sub 2}O. The structures of obtained compounds were investigated by single-crystal X-ray diffraction analysis.

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

New benzo[f]quinolino[3,4-b][1,7]naphthyridine-6,8(5H,9H)-diones: synthesis, electronic, molecular, and crystal structures. Protonation and complexation with lanthanum and europium salts

A series of novel benzo[f]quinolino[3,4-b][1,7]naphthyridine-6,8(5H,9H)-diones, which are promising ligands for the extractive separation of actinides and lanthanides, and also their complexes with lanthanum and europium were synthesized. The molecular and crystal structures of one among the ligands were determined by single crystal X-ray diffraction. The protonation of compounds was investigated by IR and NMR spectroscopy. The electronic structure of starting substances and protonated forms was estimated by DFT calculations.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Sterically hindered tetrylenes based on new 1,10-phenanthroline-containing diols: initiators for ε-caprolactone polymerization

Previously unknown tetradentate ONNO-type ligands 1–5 (4,7-di(4-R´-phenoxy)-2,9- di(HOCR{sub 2}CH)-1,10-phenanthrolines (R´ = Me, R–R = –(CH{sub 2}){sub 5}– (1), R = Me (2), R–R = 2,2-adamantylene (3); R´ = But, R–R = –(CH{sub 2}){sub 5}– (4), R = Me (5)) were synthesized by sequential treatment of 2,9-dimethyl-4,7-di(4-R´-phenoxy)-1,10-phenanthrolines 6 (R´ = Me) and 7 (R´ = Bu{sup t}) with excess LDA and appropriate dialkyl ketone. The structure of compound 4 was determined by single-crystal X-ray diffraction. Previously uncharacterized phenanthroline 6 was synthesized by the treatment of 4,7-dichloro-2,9-dimethyl-1,10-phenanthroline with excess p-cresol in the presence of KOH. The reaction of compounds 1–5 with one equivalent of Lappert´s germylene or stannylene, M[N(SiMe{sub 3}){sub 2}]{sub 2} (M = Ge, Sn), gave the corresponding germylenes 8–12 (M = Ge, R´ = Me, R–R = –(CH{sub 2}){sub 5}– (8), R = Me (9), R–R = 2,2-adamantylene (10), R´ = Bu{sup t}, R{sub 2} = –(CH{sub 2}){sub 5}– (11), R = Me (12)) and stannylenes 13–17 (M = Sn, R´ = Me, R–R = –(CH{sub 2}){sub 5}– (13), R = Me (14), R–R = 2,2-adamantylene (15), R´ = Bu{sup t}, R–R = –(CH{sub 2}){sub 5}– (16), R{sub 2} = Me (17)) in satisfactory yields. According to {sup 1}H, {sup 13}C, and {sup 119}Sn NMR data, the synthesized stannylenes are monomeric in solution, and the tin atom has a coordination number of 4. In the series of the compounds under consideration, stannylene 16 proved to be the most active initiator for e-caprolactone polymerization, whereas the germylenes were shown to be inactive in this process.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Binding of gold(III) with silver(I) dipropyldithiocarbamate: supramolecular self-assembly (role of secondary Au…S and Ag…S bonds) and thermal behavior of the ionic-polymer complex ([Au(S{sub 2}CNPr{sub 2}){sub 2}][AgCl{sub 2}]){sub n}

The double ionic-polymer complex ([Au(S{sub 2}CNPr{sub 2}){sub 2}][AgCl{sub 2}]){sub n} (1) was prepared as an individual fixation form of gold(III) from NaCl solutions with silver(I) dipropyldithiocarbamate and was characterized by single-crystal X-ray diffraction and {sup 13}C magic-angle spinning (MAS) NMR spectroscopy. The structure of 1 comprises two nonequivalent centrosymmetric complex cations [Au(S{sub 2}CNPr{sub 2}){sub 2}]{sup +} (A and B) and the discrete linear anion [AgCl{sub 2}]{sup –}. Gold(III) cations are linked by pairs of unsymmetrical secondary Au…S bonds to form linear supramolecular chains (…A…B…)n. Neighboring cations are additionally linked by [AgCl{sub 2}]{sup –} anions via secondary Ag…S and Cl…S bonds, the anions being involved in the overall stabilization of the supramolecular structure. The cation–anion interactions lead to a distortion of the linear configuration of the [AgCl{sub 2}]{sup –} anion. The character of thermolysis of 1 accompanied by quantitative regeneration of bound Au and Ag was established by simultaneous thermal analysis.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Metal-organic frameworks based on magnesium(II): adsorption and luminescence properties

Two new metal-organic frameworks based on magnesium(II) ions, [Mg{sub 4}(bdc){sub 3}(dma){sub 6}(NO{sub 3}){sub 2}]•DMA (1; bdc is 1,4-benzenedicarboxylate; dma, DMA is N,N-dimethylacetamide) and [Mg{sub 3}(bpdc){sub 3}(nmp){sub 4}] (2; bpdc is 4,4´-biphenyldicarboxylate; nmp is N-methylpyrrolidone), were synthesized in DMA or NMP, respectively. According to the single-crystal X-ray diffraction data, compound 1 is built of binuclear carboxylate units {Mg_2(O_2CR)_3}, which were previously not observed in metal-organic frameworks. Compound 2 is based on trinuclear carb oxylate units {Mg_3(O_2CR)_6}. Compound 1 has a layered structure (hcb topology), whereas compound 2 has a distorted three-dimensional cubic structure (pcu topology). The phase purity and chemical identity of the compounds were confirmed by IR spectroscopy, thermogravimetry, elemental analysis, and powder X-ray diffraction. Photoluminescence properties of both compounds are indicative of intraligand charge-transfer transitions of one (for 1) or two (for 2) types. Textural characteristics of an activated sample of 1 were measured by nitrogen and hydrogen adsorption at 77 K and by carbon dioxide adsorption at 195 K.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Decarboxylation and electrophilic substitution in 3-tert-butyl-4-oxopyrazolo[5,1-c][1,2,4]triazines

Reactivity of 7-R-3-tert-butyl-4-oxo-4,6-dihydropyrazolo[5,1-c][1,2,4]triazine-8-carboxylic acids (R = NH{sub 2}, N{sub 3}, H) and products of their decarboxylation towards different electrophilic agents (chloroacetone, Boc{sub 2}O/NaN{sub 3}, DMF/POCl{sub 3}, TMSBr, N-halosuccinimides, and HNO{sub 2}) was studied. A selective synthesis of new C(7),C(8)-functionalized and N(1)-tert-butyloxycarbonyl-substituted 4-oxopyrazolo[5,1-c][1,2,4]triazines was performed. The structures of the synthesized compounds were confirmed by IR and NMR spectroscopy, high resolution mass spectrometry and single crystal X-ray diffraction analysis.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Synthesis, Crystal Structure, Hirshfeld Surface Analysis, DFT, and DNA-Binding Studies of (E)-2-(3-Hydroxy-4-Methoxybenzylidene)Hydrazinecarbothioamide

(E)-2-(3-Hydroxy-4-methoxybenzylidene)hydrazinecarbothioamide 3 was synthesized by reacting thiosemicarbazide with 2-hydorxy-3-methoxybenzaldehyde in dry ethanol. The structure was elucidated by spectroscopic (FT-IR, {sup 1}H NMR, and {sup 13}C NMR) and single crystal X-ray diffraction techniques. A detailed analysis of the intermolecular interactions has been performed based on the Hirshfeld surfaces and their associated two-dimensional fingerprint plots. DFT, spectroscopic, and electrochemical DNA-binding analysis confirmed that the compound is reactive to bind with DNA. Viscometric studies suggested that compound 3 has a mixed mode of interaction and intercalated into the DNA base pairs predominantly along with the possibility of electrostatic interactions. .

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Discovery of high-affinity BCL6-binding peptide and its structure-activity relationship

B cell lymphoma 6 (BCL6) is a transcriptional repressor that interacts with its corepressors BcoR and SMRT. Since this protein-protein interaction (PPI) induces activation and differentiation of B lymphocytes, BCL6 has been an attractive drug target for potential autoimmune disease treatments. Here we report a novel BCL6 inhibitory peptide, F1324 (Ac-LWYTDIRMSWRVP-OH), which we discovered using phage display technology; we also discuss this peptide's structure-activity relationship (SAR). For BCL6(5-129) binding, K{sub D} and IC{sub 50} values of F1324 were 0.57 nM and 1 nM according to the results of an SPR analysis and cell-free ELISA assay, respectively. In contrast, BcoR(Arg498-514Pro) and SMRT(Leu1422-Arg1438) exhibited relatively weak micromole-order binding to BCL6. Furthermore, Fusion protein AcGFP-F1324 transiently expressed in HEK293T cells inhibited intracellular PPI in cell-based M2H assay. By examination of the truncation and fragmentation of F1324, the C-terminal sequence WRVP, which is similar to the BcoR(509-512) sequence WVVP, was identified as being critical for BCL6 binding. In addition, subsequent single-crystal X-ray diffraction analysis of F1324/BCL6(5-129) complex revealed that the high affinity of F1324 was caused by effective interaction of its side chains while its main chain structure was similar to that of BcoR(Arg498-514Pro). To our knowledge, F1324 is the strongest BCL6-binding peptide yet reported. - Highlights: • F1324 was discovered as 5000-times higher affinity peptide to BCL6 than that of BcoR(R498-P514). • X-ray crystal structure analysis revealed the binding mode. • To our knowledge, F1324 is the strongest BCL6-binding and -inhibition peptide so far.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Pyrene-fused hexaarylbenzene luminogens: Synthesis, characterization, and aggregation-induced emission enhancement

Six novel pyrene-fused hexaarylbenzene derivatives (3a-f) were designed, synthesized, and characterized, which exhibited aggregation-induced emission enhancement (AIEE) in the aggregated state by means of THF/H 2 O mixtures. Techniques such as theoretical calculations, single crystal X-ray diffraction, and photophysical measurements in solution and in the solid state were employed to illustrate the tunable, variable, and sensitive AIEE features in this system. Both theoretical and experimental results revealed that the nature of the multiple photoluminescence should be taken into account when elucidating and designing the multiple photoluminescence phenomenon and molecules.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Dual origin of ferropericlase inclusions within super-deep diamonds

Ferropericlase [(Mg,Fe)O] is one of the major constituents of Earth's lower mantle and the most abundant mineral inclusion in sub-lithospheric diamonds. Although a lower mantle origin for ferropericlase inclusions has often been suggested, some studies have proposed that many of these inclusions may instead form at much shallower depths, in the deep upper mantle or transition zone. No straightforward method exists to discriminate ferropericlase of lower-mantle origin without characteristic mineral associations, such as co-existing former bridgmanite. To explore ferropericlase-diamond growth relationships, we have investigated the crystallographic orientation relationships (CORs), determined by single-crystal X-ray diffraction, between 57 ferropericlase inclusions and 37 diamonds from Juina (Brazil) and Kankan (Guinea). We show that ferropericlase inclusions can develop specific (16 inclusions in 12 diamonds), rotational statistical (9 inclusions in 7 diamonds) and random (32 inclusions in 25 diamond) CORs with respect to their diamond hosts. All measured inclusions showing a specific COR were found to be Fe-rich (X FeO > 0.30). Coexistence of non-randomly and randomly oriented ferropericlase inclusions within the same diamond indicates that their CORs may be variably affected by local growth conditions. However, the occurrence of specific CORs only for Fe-rich inclusions indicates that Fe-rich ferropericlases have a distinct genesis and are syngenetic with their host diamonds. In conclusion, this result provides strong support for a dual origin for ferropericlase in Earth's mantle, with Fe-rich compositions likely indicating redox growth in the upper mantle, while more Mg-rich compositions with random COR mostly representing ambient lower mantle trapped as protogenetic inclusions.

58 GEOSCIENCES↗
DOE OSTI2017

1-D calcium, 2-D zinc and 3-D manganese coordination polymers derived from pyrazine-2,3,5,6-tetracarboxylic acid

Three coordination polymers were synthesized from pyrazine-2,3,5,6-tetracarboxylic acid (H 4 pztc) in combination with calcium, zinc and manganese ions under hydrothermal conditions and their structures were determined by single crystal X-ray diffraction, powdered X-ray diffraction, Fourier transformed infrared spectroscopy, thermogravimetric and elemental analyses. Structure 1, {(Ca(H 2 pztc)(H 2 O) 3 )n, crystallizes as 1-D chains, with the partially deprotonated ligand in –O,N,O– coordination mode and with the Ca atoms in an uncommon nine coordinate environment. Structure 2, {Zn1(pztc)(H 2 O) 2 Zn2(H 2 O) 4 } n , is an infinite, 2-D coordination network that contains two nonequivalent Zn atoms, each with octahedral geometry, and the fully deprotonated pztc 4- in bis-bridging chelating coordination mode. The stacked 2-D layers are stabilized by extensive inter-layer water-carboxylate hydrogen-bonding with an inter-layer distance of 4.9 Å. Structure 3, {(Mn 2 (pztc)(H 2 O) 2 )} n , is a covalently bonded 3-D network containing two nonequivalent Mn atoms, each with octahedral geometry, and the fully deprotonated pztc 4- units. Structure 3 exhibits paramagnetic behavior at room temperature, and weak antiferromagnetic properties at very low temperature, which is consistent with their nearest Mn…Mn separation distance of 4.9 Å.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Highly efficient phosphorescence from cyclometallated iridium(III) compounds: Improved syntheses of picolinate complexes and quantum chemical studies of their electronic structures

In this work, we report a new method to make heteroleptic cyclometallated iridium(III) complexes that employs 1,2-dimethoxyethane (DME) instead of the commonly used 2-ethoxyethanol for the addition of ancillary ligands to chloro-bridged dimeric iridium species. Thus, picolinic acid was quickly and cleanly added to [(F 2 ppy)2Ir(Cl)]2 (where F 2 ppy=2-(4',6'-difluorophenyl)pyridinato) with base under DME reflux to afford (F 2 ppy) 2 Ir(picolinate) (FIrpic) in excellent yield. The high purity of the products obviates the need for further purification, an improvement over the common route in which column chromatography is required. We prepared eleven picolinate complexes by this route, eight of which were characterized by single crystal x-ray diffraction. The complexes possess the same distorted octahedral geometry with two bidentate phenylpyridine ligands and one bidentate 2-picolinate ligand. All of the compounds exhibited efficient phosphorescence with colors ranging from blue to orange; photophysical measurements revealed emission quantum yields as high as 0.92, while most surpassed 0.5. Time-dependent density functional theory calculations, coupled with the use of natural transition orbitals (NTOs), allowed a detailed interpretation of the electronic structures for the complexes. The nature of the acceptor orbital for the lowest-energy triplet state NTO was discovered to be an important predictor for the emission spectra of FIrpic and its congeners.

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

Synthesis and spectroscopic characterization of actinyl(VI) tetrahalide coordination compounds containing 2, 2'-bipyridine

A series of three new actinide tetrahalide coordination compounds containing 2,2'-bipyridinium (H 2 bpy) have been synthesized by room temperature evaporation and characterized via single crystal X-ray diffraction, Raman spectroscopy, and infrared spectroscopy. The solid-state compounds (Np1, U1, and U2) contain the AnO 2 2+ cation coordinated to four halide (chloride or bromide) atoms to form the anionic tetrahalide molecular unit [AnO 2 X 4 ] 2– (X = Cl, Br) and are charge balanced by the 2,2'-bipyridinium cations that engage in electrostatic interactions with the actinyl complex. Np1 (N 2 C 10 H 10 )[NpO 2 Cl 4 ] contains 2,2'-bipyridine in the cis conformation where both the nitrogen atoms are directed towards the [NpO 2 Cl 4 ] 2– monomer. Within U1 (N 2 C 10 H 9 )[UO 2 Cl 4 ], the 2,2'-bipyridine is in a trans conformation, and found in the same orientation in the isomorphous structure U2 (N 2 C 10 H 9 )[UO 2 Br 4 ]. The compounds were further characterized by vibrational spectroscopy with specific interest in the actinyl cation. Raman spectroscopy provided information on the actinyl symmetric stretch (ν 1 ) whereas IR spectroscopy is used to determine the location of the asymmetric stretch (ν 3 ). Here, spectral similarities are observed between the two isomorphous structures, but slight variations across the series of structures are found to be associated with bipyridine bands in the various conformations. Additional analysis of these vibrational features in U1 and U2 provided information on the actinyl force constants, allowing insight into the relative uranyl bond strength that was compared to similar tetrahalide compounds.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗