Browse
Submit Data
Databases
API
Help

Dataset Information

14 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Pentafluoroethylaluminates: A Combined Synthetic, Spectroscopic, and Structural Study.

ABSTRACT: Salts of the tetrakis(pentafluoroethyl)aluminate anion [Al(C₂ F₅ )₄ ]^- were obtained from AlCl₃ and LiC₂ F₅ . They were isolated with different counter-cations and characterized by NMR and vibrational spectroscopy and mass spectrometry. Degradation of the [Al(C₂ F₅ )₄ ]^- ion was found to proceed via 1,2-fluorine shifts and stepwise loss of CF(CF₃ ) under formation of [(C₂ F₅ )_4-n AlF_n ]^- (n=1-4) as assessed by NMR spectroscopy and mass spectrometry and supported by results of DFT calculations. In addition, the [(C₂ F₅ )AlF₃ ]^- ion was structurally characterized.

SUBMITTER: Bischoff LA

PROVIDER: S-EPMC7689865 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Pentafluoroethylaluminates: A Combined Synthetic, Spectroscopic, and Structural Study.

Bischoff Lisa A LA Riefer Jarno J Wirthensohn Raphael R Bischof Tobias T Bertermann Rüdiger R Ignat'ev Nikolai V NV Finze Maik M

Chemistry (Weinheim an der Bergstrasse, Germany) 20200720 60

Salts of the tetrakis(pentafluoroethyl)aluminate anion [Al(C2 F5 )4 ]- were obtained from AlCl3 and LiC2 F5 . They were isolated with different counter-cations and characterized by NMR and vibrational spectroscopy and mass spectrometry. Degradation of the [Al(C2 F5 )4 ]- ion was found to proceed via 1,2-fluorine shifts and stepwise loss of CF(CF3 ) under formation o ...[more]

PMID: 32167200

Similar Datasets

Bright Luminescence in Three Phases-A Combined Synthetic, Spectroscopic and Theoretical Approach.

Project description:Combining phase-dependent photoluminescence (PL) measurements and quantum chemical calculations is a powerful approach to help understand the influence of the molecular surroundings on the PL properties. Herein, a phosphine functionalized amidinate was used to synthesize a recently presented bimetallic gold complex, featuring an unusual charge separation. The latter was subsequently used as metalloligand to yield heterotetrametallic complexes with an Au-M-M-Au "molecular wire" arrangement (M=Cu, Ag, Au) featuring metallophilic interactions. All compounds show bright phosphorescence in the solid state, also at ambient temperature. The effect of the molecular environment on the PL was studied in detail for these tetrametallic complexes by comparative measurements in solution, in the solid state and in the gas phase and contrasted to time-dependent density functional theory computations.

| S-EPMC8597132 | biostudies-literature

Molecular Crystal Forms of Antitubercular Ethionamide with Dicarboxylic Acids: Solid-State Properties and a Combined Structural and Spectroscopic Study.

Project description:We report on the preparation, characterization, and bioavailability properties of three new crystal forms of ethionamide, an antitubercular agent used in the treatment of drug-resistant tuberculosis. The new adducts were obtained by combining the active pharmaceutical ingredient with three dicarboxylic acids, namely glutaric, malonic and tartaric acid, in equimolar ratios. Crystal structures were obtained for all three adducts and were compared with two previously reported multicomponent systems of ethionamide with maleic and fumaric acid. The ethionamide-glutaric acid and the ethionamide-malonic acid adducts were thoroughly characterized by means of solid-state NMR (13C and 15N Cross-Polarization Magic Angle Spinning or CPMAS) to confirm the position of the carboxylic proton, and they were found to be a cocrystal and a salt, respectively; they were compared with two previously reported multicomponent systems of ethionamide with maleic and fumaric acid. Ethionamide-tartaric acid was found to be a rare example of kryptoracemic cocrystal. In vitro bioavailability enhancements up to a factor 3 compared to pure ethionamide were assessed for all obtained adducts.

| S-EPMC7559828 | biostudies-literature

Structural, spectroscopic, and electrochemical properties of nonheme Fe(II)-hydroquinonate complexes: synthetic models of hydroquinone dioxygenases.

Project description:Using the tris(3,5-diphenylpyrazol-1-yl)borate ((Ph2)Tp) supporting ligand, a series of mono- and dinuclear ferrous complexes containing hydroquinonate (HQate) ligands have been prepared and structurally characterized with X-ray crystallography. The monoiron(II) complexes serve as faithful mimics of the substrate-bound form of hydroquinone dioxygenases (HQDOs) - a family of nonheme Fe enzymes that catalyze the oxidative cleavage of 1,4-dihydroxybenzene units. Reflecting the variety of HQDO substrates, the synthetic complexes feature both mono- and bidentate HQate ligands. The bidentate HQates cleanly provide five-coordinate, high-spin Fe(II) complexes with the general formula [Fe((Ph2)Tp)(HL(X))] (1X), where HL(X) is a HQate(1-) ligand substituted at the 2-position with a benzimidazolyl (1A), acetyl (1B and 1C), or methoxy (1D) group. In contrast, the monodentate ligand 2,6-dimethylhydroquinone (H(2)L(F)) exhibited a greater tendency to bridge between two Fe(II) centers, resulting in formation of [Fe(2)((Ph2)Tp)(2)(μ-L(F))(MeCN)]·[2F(MeCN)]. However, addition of one equivalent of "free" pyrazole ((Ph2)pz) ligand provided the mononuclear complex, [Fe((Ph2)Tp)(HL(F))((Ph2)pz)]·[1F((Ph2)pz)], which is stabilized by an intramolecular hydrogen bond between the HL(F) and (Ph2)pz donors. Complex 1F((Ph2)pz) represents the first crystallographically-characterized example of a monoiron complex bound to an untethered HQate ligand. The geometric and electronic structures of the Fe/HQate complexes were further probed with spectroscopic (UV-vis absorption, (1)H NMR) and electrochemical methods. Cyclic voltammograms of complexes in the 1X series revealed an Fe-based oxidation between 0 and -300 mV (vs. Fc(+/0)), in addition to irreversible oxidation(s) of the HQate ligand at higher potentials. The one-electron oxidized species (1X(OX)) were examined with UV-vis absorption and electron paramagnetic resonance (EPR) spectroscopies.

| S-EPMC3891569 | biostudies-literature

Spectroscopic and Structural Study of a New Conducting Pyrazolium Salt.

Project description:The increase in conductivity with temperature in 1H-pyrazol-2-ium 2,6-dicarboxybenzoate monohydrate was analyzed, and the influence of the mobility of the water was discussed in this study. The electric properties of the salt were studied using the impedance spectroscopy method. WB97XD/6-311++G(d,p) calculations were performed, and the quantum theory of atoms in molecules (QTAiM) approach and the Hirshfeld surface method were applied to analyze the hydrogen bond interaction. It was found that temperature influences the spectroscopic properties of pyrazolium salt, particularly the carbonyl and hydroxyl frequencies. The influence of water molecules, connected by three-center hydrogen bonds with co-planar tetrameters, on the formation of structural defects is also discussed in this report.

| S-EPMC8347911 | biostudies-literature

A spectroscopic study of structural heterogeneity and carbon monoxide binding in neuroglobin.

Project description:Neuroglobin (Ngb) is a small globular protein that binds diatomic ligands like oxygen, carbon monoxide (CO) and nitric oxide at a heme prosthetic group. We have performed FTIR spectroscopy in the infrared stretching bands of CO and flash photolysis with monitoring in the electronic heme absorption bands to investigate structural heterogeneity at the active site of Ngb and its effects on CO binding and migration at cryogenic temperatures. Four CO stretching bands were identified; they correspond to discrete conformations that differ in structural details and CO binding properties. Based on a comparison of bound-state and photoproduct IR spectra of the wild-type protein, Ngb distal pocket mutants and myoglobin, we have provided structural interpretations of the conformations associated with the different CO bands. We have also studied ligand migration to the primary docking site, B. Rebinding from this site is governed by very low enthalpy barriers (?1 kJ/mol), indicating an extremely reactive heme iron. Moreover, we have observed ligand migration to a secondary docking site, C, from which CO rebinding involves higher enthalpy barriers.

| S-EPMC3456330 | biostudies-other

Probing the effectiveness of spectroscopic reporter unnatural amino acids: a structural study.

Project description:The X-ray crystal structures of superfolder green fluorescent protein (sfGFP) containing the spectroscopic reporter unnatural amino acids (UAAs) 4-cyano-L-phenylalanine (pCNF) or 4-ethynyl-L-phenylalanine (pCCF) at two unique sites in the protein have been determined. These UAAs were genetically incorporated into sfGFP in a solvent-exposed loop region and/or a partially buried site on the ?-barrel of the protein. The crystal structures containing the UAAs at these two sites permit the structural implications of UAA incorporation for the native protein structure to be assessed with high resolution and permit a direct correlation between the structure and spectroscopic data to be made. The structural implications were quantified by comparing the root-mean-square deviation (r.m.s.d.) between the crystal structure of wild-type sfGFP and the protein constructs containing either pCNF or pCCF in the local environment around the UAAs and in the overall protein structure. The results suggest that the selective placement of these spectroscopic reporter UAAs permits local protein environments to be studied in a relatively nonperturbative fashion with site-specificity.

| S-EPMC4756619 | biostudies-literature

Rotational Isomerism of an Amide Substituted Squaraine Dye: A Combined Spectroscopic and Computational Study.

Project description:The conformational analysis of a 2,4-bis(4-dialkylamino-2-amido)phenyl squaraine dye revealed the presence of two rotational isomers at room temperature. Combination of spectroscopic and computational techniques showed that the rotational barrier is influenced by hydrogen bonds between the amido substituents and the oxygen atoms at the quadratic core. Even small amounts of trifluoroacetic acid interfered with the intramolecular hydrogen bond formation and accelerated the interconversion of the conformers.

| S-EPMC8453623 | biostudies-literature

Synthetic and Structural Study of peri-Substituted Phosphine-Arsines.

Project description:A series of phosphorus-arsenic peri-substituted acenaphthene species have been isolated and fully characterised, including single crystal X-ray diffraction. Reactions of EBr3 (E = P, As) with iPr2PAcenapLi (Acenap = acenaphthene-5,6-diyl) afforded the thermally stable peri-substitution supported donor-acceptor complexes, iPr2PAcenapEBr23 and 4. Both complexes show a strong P→E dative interaction, as observed by X-ray crystallography and 31P NMR spectroscopy. DFT calculations indicated the unusual As∙∙∙As contact (3.50 Å) observed in the solid state structure of 4 results from dispersion forces rather than metallic interactions. Incorporation of the excess AsBr3 in the crystal structure of 3 promotes the formation of the ion separated species [iPr2PAcenapAsBr]+Br- 5. A decomposition product 6 containing the rare [As6Br8]2- heterocubane dianion was isolated and characterised crystallographically. The reaction between iPr2PAcenapLi and EtAsI2 afforded tertiary arsine (BrAcenap)2AsEt 7, which was subsequently lithiated and reacted with PhPCl2 and Ph2PCl to afford cyclic PhP(Acenap)2AsEt 8 and acyclic EtAs(AcenapPPh2)2 9.

| S-EPMC8658757 | biostudies-literature

Combined Mossbauer spectroscopic, multi-edge X-ray absorption spectroscopic, and density functional theoretical study of the radical SAM enzyme spore photoproduct lyase.

Project description:Spore photoproduct lyase (SPL), a member of the radical S-adenosyl-L-methionine (SAM) superfamily, catalyzes the direct reversal of the spore photoproduct, a thymine dimer specific to bacterial spores, to two thymines. SPL requires SAM and a redox-active [4Fe-4S] cluster for catalysis. Mössbauer analysis of anaerobically purified SPL indicates the presence of a mixture of cluster states with the majority (40 %) as [2Fe-2S](2+) clusters and a smaller amount (15 %) as [4Fe-4S](2+) clusters. On reduction, the cluster content changes to primarily (60 %) [4Fe-4S](+). The speciation information from Mössbauer data allowed us to deconvolute iron and sulfur K-edge X-ray absorption spectra to uncover electronic (X-ray absorption near-edge structure, XANES) and geometric (extended X-ray absorption fine structure, EXAFS) structural features of the Fe-S clusters, and their interactions with SAM. The iron K-edge EXAFS data provide evidence for elongation of a [2Fe-2S] rhomb of the [4Fe-4S] cluster on binding SAM on the basis of an Fe···Fe scatterer at 3.0 Å. The XANES spectra of reduced SPL in the absence and presence of SAM overlay one another, indicating that SAM is not undergoing reductive cleavage. The X-ray absorption spectroscopy data for SPL samples and data for model complexes from the literature allowed the deconvolution of contributions from [2Fe-2S] and [4Fe-4S] clusters to the sulfur K-edge XANES spectra. The analysis of pre-edge features revealed electronic changes in the Fe-S clusters as a function of the presence of SAM. The spectroscopic findings were further corroborated by density functional theory calculations that provided insights into structural and electronic perturbations that can be correlated by considering the role of SAM as a catalyst or substrate.

| S-EPMC4089880 | biostudies-literature

Spectroscopic and Structural Study of Some Oligosilanylalkyne Complexes of Cobalt, Molybdenum and Nickel.

Project description:Metal induced stabilization of α-carbocations is well known for cobalt- and molybdenum complexed propargyl cations. The same principle also allows access to reactivity enhancement of metal coordinated halo- and hydrosilylalkynes. In a previous study, we have shown that coordination of oligosilanylalkynes to the dicobalthexacarbonyl fragment induces striking reactivity to the oligosilanyl part. The current paper extends this set of oligosilanylalkyne complexes to a number of new dicobalthexacarbonyl complexes but also to 1,2-bis(cyclopentadienyl)tetracarbonyldimolybdenum and (dippe)Ni complexes. NMR-Spectroscopic and crystallographic analysis of the obtained complexes clearly show that the dimetallic cobalt and molybdenum complexes cause rehybridization of the alkyne carbon atoms to sp³, while in the nickel complexes one π-bond of the alkyne is retained. For the dicobalt and dimolybdenum complexes, strongly deshielded 29Si NMR resonances of the attached silicon atoms indicate enhanced reactivity, whereas the 29Si NMR shifts of the respective nickel complexes are similar to that of respective vinylsilanes.

| S-EPMC6337173 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data