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Janina Kopyra, Franck Rabilloud, Hassan Abdoul-Carime
Understanding the fundamental processes underlying the interaction of organometallic compounds with low energy electrons is desirable for optimizing methodologies for nanoscale applications. In this work, we couple experimental measurements with theories to investigate the interaction of gas phase copper(ii) acetylacetonate, Cu(acac)2 , with low energy (<12 eV) electrons. Near 0 eV, a multipole-bound anion is likely to act as the doorway for the formation of a transitory molecular anion which then undergoes stabilization via a 90°-rotation of one of the acac units...
March 5, 2018: Physical Chemistry Chemical Physics: PCCP
Taotao Lu, Zhiming Liu, Carlos A Steren, Fan Fei, Tabitha M Cook, Xue-Tai Chen, Zi-Ling Xue
A series of Ni(ii), Pd(ii) and Pt(ii) complexes [ML][PF6 ]2 [L = L1 , M = Ni (1), Pd (2), Pt (3); L = L2 , M = Ni (4), Pd (5), Pt (6)] and [Pt(L2 )(acac)] (7) have been prepared by the reactions of two tetradentate macrocyclic amine-NHC ligand precursors, [H2 L1 ][PF6 ]2 and [H2 L2 ][PF6 ]2 , with Ni(OAc)2 ·4H2 O, Pd(OAc)2 and Pt(acac)2 in the presence of NaOAc. Complex 7 is isolated along with 6 from the same reaction between [H2 L2 ][PF6 ]2 and Pt(acac)2 . There are two atropisomers in 1-3 and two achiral conformers in 4-6...
February 28, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Shahid Ameen, Seul Bee Lee, Yong Guk Lee, Sung Cheol Yoon, Jaemin Lee, Changjin Lee
Simple but exceptionally efficient 4-diphenylaminocarbazole host material, 4-DPACz, is presented and compared with its positional isomer, 1-DPACz. The shift of diphenylamino substituent from 1-position to 4-position of carbazole resulted into increase of HOMO energy level as well as increase of triplet energy level. Having high triplet energy level (2.76 eV) and well-matched HOMO energy level (-5.61 eV), 4-DPACz showed reduced driving voltage and higher efficiencies for solution-processed green PhOLEDs than PVK as well as 1-DPACz...
February 26, 2018: ACS Applied Materials & Interfaces
Olivier Placide Noté, Line Made Simo, Joséphine Ngo Mbing, Dominique Guillaume, Christian Dominique Muller, Dieudonné Emmanuel Pegnyemb, Annelise Lobstein
As a continuation of our interest in the study of triterpenoid saponins from Albizia zygia, phytochemical investigation of its stem barks led to the isolation of two new oleanane-type saponins, named zygiaosides C-D (1-2). Their structures were established on the basis of extensive analysis of 1D and 2D NMR (1H-, 13C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as, 3-O-[ β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→6)]-β-d-glucopyranosyl]-21-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-O-α-l-arabinofuranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl ester (1) and 3- O-[β-d-glucopyranosyl-(1→2) -[ β-d-fucopyranosyl-(1→6)]-β-d-glucopyranosyl]-21-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-O-α-l-arabinofuranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl ester (2)...
February 19, 2018: Natural Product Research
Olivier Placide Noté, Joséphine Ngo Mbing, Marie-Claude Kilhoffer, Dieudonné Emmanuel Pegnyemb, Annelise Lobstein
One new acacic acid-type saponin, named lebbeckoside C (1), was isolated from the stem barks of Albizia lebbeck. Its structure was established on the basis of extensive analysis of 1D and 2D NMR (1 H,13 C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as 3-O-[β-d-xylopyranosyl-(l→2)-β-d-fucopyranosyl-(1→6)-[β-d-glucopyranosyl(1→2)]-β-d-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl)octa-2,7-dienoyl]-β-d-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28 O-[β-d-quinovopyranosyl-(l→3)-[α-l-arabinofuranosyl-(l→4)]-α-l-rhamnopyranosyl-(l→2)-β-d-glucopyranosyl] ester...
February 19, 2018: Natural Product Research
Antonella Muscella, Carla Vetrugno, Luca Giulio Cossa, Giovanna Antonaci, Amilcare Barca, Sandra Angelica De Pascali, Francesco Paolo Fanizzi, Santo Marsigliante
[This corrects the article DOI: 10.1371/journal.pone.0181114.].
2018: PloS One
Mainak Debnath, Malay Dolai, Kaberi Pal, Sourav Bhunya, Ankan Paul, Hon Man Lee, Mahammad Ali
The mono- and dinuclear oxidovanadium(v) complexes [VVO(L1)(Cl)] (1) and [L1VVO(μ2-O)VO(L1)] (2) of ONNO donor amine-bis(phenolate) ligand (H2L1) were readily synthesized by the reaction between H2L1 and VCl3.(THF)3 or VO(acac)2 in MeOH or MeCN, respectively, and then characterized through mass spectroscopy, 1H-NMR and FTIR techniques. Both the complexes possess distorted octahedral geometry around each V centre. Upon the addition of 1 equivalent or more acid to a MeCN solution of complex 1, it immediately turned into the protonated form, which might be in equilibrium as: [L1ClVV[double bond, length as m-dash]OH]+ ↔ [L1ClVV-OH]+ (in the case of [L1ClVV[double bond, length as m-dash]OH]+ oxo-O is just protonated, whereas in [L1ClVV-OH]+ it is a hydroxo species), with the shift in λmax from 610 nm to 765 nm...
February 8, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Wenxuan Song, Lijiang Shi, Lei Gao, Peijun Hu, Haichuan Mu, Zhenyuan Xia, Jinhai Huang, Jianhua Su
The electron-accepting [1,2,4]triazolo[1,5-a]pyridine (TP) moiety was introduced to build bipolar host materials for the first time, and two host materials based on this TP acceptor and carbazole donor, namely o-CzTP, m-CzTP, were designed and synthesized. These two TP-based host materials possess high triplet energy (>2.9 eV) and appropriate HOMO/LUMO levels as well as the bipolar transporting feature, which permit their applicability as universal host materials in multicolor phosphorescent organic light-emitting devices (PhOLEDs)...
January 25, 2018: ACS Applied Materials & Interfaces
Deepika Lakshmi Ramasamy, Ville Puhakka, Sidra Iftekhar, Anna Wojtuś, Eveliina Repo, Samia Ben Hammouda, Evgenia Iakovleva, Mika Sillanpää
Silica-chitosan hybrid beads were synthesized via three different methods to investigate the selective recovery of REE from AMD. The influence of amino/non-amino silanes, high molecular weight/high viscous chitosan and N-/O- based ligands were studied and their effects on REE removal efficiencies were analyzed. The adsorption efficiencies of three various groups of modified beads were inspected with respect to feed pH, in a single and a multi-component system, and their affinities towards the light and heavy rare earth elements (LREE/ HREEs) were interpreted to understand the intra-series REE separation behavior...
January 20, 2018: Journal of Hazardous Materials
A O Youssef
A novel, simple, sensitive and selective spectrofluorimetric method was developed for the determination of Acetazolamide in pharmaceutical tablets and serum samples using photo probe Tb3+-ACAC. The Acetazolamide can remarkably quench the luminescence intensity of Tb3+-ACAC complex in DMSO at pH 6.8 and λex = 350 nm. The quenching of luminescence intensity of Tb3+-ACAC complex especially the electrical band at λem = 545 nm is used for the assessment of Acetazolamide in the pharmaceutical tablet and serum samples...
January 20, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Ningqiang Zhang, Lingcong Li, Jinsheng Zhao, Tingting Yang, Guizhen Zhang, Hong He, Shaorui Sun
In this paper, we present an approach for the precisely controlled phase transformation of MnO2 in order to synthesise different compositions of α-/β-MnO2 materials, by adding a trace amount of Zn(acac)2 as the phase transformation-inducing agent in a hydrothermal reaction. The single-atomic dispersion of Zn might reduce the barrier of phase transformation of δ-MnO2 to β-MnO2. The ratio of the Zn species present in the single-atomic dispersions and nanoclusters might dominate the generation of α-MnO2 and β-MnO2...
January 23, 2018: Chemical Communications: Chem Comm
Huidan Wei, Yongtao Wang, Jia Yao, Haoran Li
The physicochemical properties including melting point, density, viscosity, conductivity, and surface tension as well as spectral properties such as infrared and EPR spectra of the chelate-based ILs [Cnmim][Cu(F6-acac)3] (n = 6, 8, 10, 12, 14) were studied as functions of temperature and chain length. The thermodynamic properties such as the standard molar entropy and crystal energy were estimated by Glasser's theory, the molar enthalpy of vaporization was calculated by Kabo's method, and the ionicity was estimated by the Walden rule...
January 22, 2018: Physical Chemistry Chemical Physics: PCCP
Maofan Li, Jiajie Liu, Tongchao Liu, Mingjian Zhang, Feng Pan
A carbonyl-bridged single molecular precursor LiTM(acac)3 [transition metal (TM) = cobalt/manganese/nickel (Co/Mn/Ni), acac = acetylacetone], featuring a one-dimensional chain structure, was designed and applied to achieve the layered oxide cathode materials: LiTMO2 (TM = Ni/Mn/Co, NMC). As examples, layered oxides, primary LiCoO2, binary LiNi0.8Co0.2O2 and ternary LiNi0.5Mn0.3Co0.2O2 were successfully prepared to be used as cathode materials. When they are applied to lithium-ion batteries (LIBs), all exhibit good electrochemical performance because of their unique morphology and great uniformity of element distribution...
January 19, 2018: Chemical Communications: Chem Comm
Kota Shiba, Takuya Kataoka, Motohiro Tagaya
The aggregation/dispersion of luminescent species is a critical factor that determines their luminescence properties. In this study, europium(iii) acetylacetonate (Eu(acac)3) was doped into a titania matrix to form Eu(acac)3-doped titania particles with well-defined size and shape through a microreactor-based sol-gel approach. The morphology and structure of the as-synthesized products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy and X-ray diffraction measurements...
January 18, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Cornelius von Morze, Michael A Ohliger, Irene Marco-Rius, David M Wilson, Robert R Flavell, David Pearce, Daniel B Vigneron, John Kurhanewicz, Zhen J Wang
PURPOSE: The purpose of this study was to investigate the hyperpolarized ketone body 13 C-acetoacetate (AcAc) and its conversion to 13 C-β-hydroxybutyrate (βOHB) in vivo, catalyzed by β-hydroxybutyrate dehydrogenase (BDH), as a novel direct marker of mitochondrial redox state. METHODS: [1,3-13 C2 ]AcAc was synthesized by hydrolysis of the ethyl ester, and hyperpolarized via dissolution DNP. Cold storage under basic conditions resulted in sufficient chemical stability for use in hyperpolarized (HP) MRI studies...
January 3, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Wei Jie Teo, Shaozhong Ge
We report the first catalytic diborylation of 1,1-disubstituted vinylarenes with pinacolborane using a cobalt catalyst generated from bench-stable Co(acac)2 and xantphos. A wide range of 1,1-disubstituted vinylarenes underwent this transformation to produce the corresponding gem-bis(boryl)alkanes in modest to high yields. This cobalt-catalyzed reaction can be readily conducted on a gram scale without the use of a dry box and represents a practical and effective approach to prepare a wide range of branched gem-bis(boryl)alkanes...
February 5, 2018: Angewandte Chemie
Sanjib Panda, Abhishek Mandal, Prabir Ghosh, Goutam Kumar Lahiri
The impact of the {Ru(acac)2 } (acac- = acetylacetonate) framework on the transformations of C-H and C-H/C-C bonds of coordinated β-diketiminate and ketodiimine scaffolds, respectively, has been addressed. It includes the following transformations involving {Ru(acac)2 } coordinated β-diketiminate in 1 and ketodiimine in 2 with the simultaneous change in metal oxidation state: (i) insertion of oxygen into the C(sp2 )-H bond of β-diketiminate in 1, leading to the metalated ketodiimine in 2 and (ii) Bronsted acid (CH3 COOH) assisted cleavage of unstrained C(sp2 )-C(sp2 )/C═N bonds of chelated ketodiimine (2) with the concomitant formation of intramolecular C-N bond in 3, as well as insertion of oxygen into the C(sp3 )-H bond of 2 to yield -CHO function in 4 (-CH3 → -CHO)...
December 18, 2017: Inorganic Chemistry
Izabella Krucińska, Bogusława Żywicka, Agnieszka Komisarczyk, Maria Szymonowicz, Stanisława Kowalska, Ewa Zaczyńska, Marcin Struszczyk, Anna Czarny, Piotr Jadczyk, Barbara Umińska-Wasiluk, Zbigniew Rybak, Marek Kowalczuk
In response to the demand for new implant materials characterized by high biocompatibility and bioresorption, two prototypes of fibrous nanocomposite implants for osseous tissue regeneration made of a newly developed blend of poly(l-lactide- co -glycolide) (PLGA) and syntheticpoly([ R,S ]-3-hydroxybutyrate), PLGA/PHB, have been developed and fabricated. Afibre-forming copolymer of glycolide and l-lactide (PLGA) was obtained by a unique method of synthesis carried out in blocksusing Zr(AcAc)₄ as an initiator...
November 29, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Foteini E Kakaroni, Alexandra Collet, Eirini Sakellari, Demetrios I Tzimopoulos, Milosz Siczek, Tadeusz Lis, Mark Murrie, Constantinos J Milios
The solvothermal reaction between Cr(acac)3 , MCl2 ·6H2 O (M = Ni, Co) and 2-hydroxy-4-methyl-6-phenyl-pyridine-3-amidoxime (H2 L), under basic conditions, led to the synthesis of the heterometallic heptanuclear clusters [MCr(HLzw )6 (HL)6 ]·3Cl (M = Ni, 1; Co, 2), with the nickel analogue displaying an S = 9/2 spin ground-state.
December 19, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Lujia Mao, Rüdiger Bertermann, Katharina Emmert, Kálmán J Szabó, Todd B Marder
An efficient methodology for the synthesis of vinyl-, allyl-, and (E)-2-boryl allylboronates from propargylic alcohols via Cu-catalyzed borylation under mild conditions is reported. In the presence of commercially available Cu(OAc)2 or Cu(acac)2 and Xantphos, the reaction affords the desired products in up to 92% yield with a broad substrate scope (43 examples). Isolation of an allenyl boronate as the reaction intermediate suggests that an insertion-elimination-type reaction, followed by borylcupration, is involved in the borylation of propargylic alcohols...
December 15, 2017: Organic Letters
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