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https://www.readbyqxmd.com/read/28078748/low-temperature-hydrogenation-of-carbon-dioxide-to-methanol-with-a-homogeneous-cobalt-catalyst
#1
Jacob Schneidewind, Rosa Adam, Wolfgang Baumann, Ralf Jackstell, Matthias Beller
Herein we describe the first homogeneous non-noble metal catalyst for the hydrogenation of CO2 to methanol. The catalyst is formed in situ from [Co(acac)3 ], Triphos, and HNTf2 and enables the reaction to be performed at 100 °C without a decrease in activity. Kinetic studies suggest an inner-sphere mechanism, and in situ NMR and MS experiments reveal the formation of the active catalyst through slow removal of the acetylacetonate ligands.
January 12, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28075589/water-soluble-ruthenium-ii-chiral-heteroleptic-complexes-with-amoebicidal-in-vitro-and-in-vivo-activity
#2
Yanis Toledano-Magaña, Juan Carlos García-Ramos, Carolina Torres-Gutiérrez, Cristina Vázquez-Gasser, José Manuel Esquivel-Sánchez, Marcos Flores-Alamo, Luis Ortiz-Frade, Rodrigo Galindo-Murillo, Mario Nequiz, Marco Gudiño-Zayas, Juan Pedro Laclette, Julio César Carrero, Lena Ruiz-Azuara
Three novel water soluble Ru(II) chiral heteroleptic coordination compounds [Ru(en)(pdto)]Cl2 (1), [Ru(gly)(pdto)]Cl (2) and [Ru(acac)(pdto)]Cl (3) where pdto= 1,8-bis-(2-pyridyl)-3,6-dithioctane, en= ethylendiamine, gly= glycinate and acac= acetylacetonate have been synthesised and have shown remarkable amoebicidal activity in vitro and in vivo. The crystal structures of compounds 1-3 are described. The in vitro IC50 values found are within nanomolar range (0.14, 0.12 and 0.06 µM for compounds 1, 2 and 3, respectively)...
January 11, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28066996/selective-hydrogenation-of-nitriles-to-primary-amines-using-a-new-cobalt-phosphine-catalyst
#3
Rosa Adam, Charles Bheeter, Jose Cabrero-Antonino, Kathrin Junge, Ralf Jackstell, Matthias Beller
A general protocol for the catalytic hydrogenation of nitriles to primary amines using a non-noble metal based system is presented. Co(acac)3 in combination with tris(2-(dicyclohexylphosphanyl)ethyl) phosphane L3 catalyses efficiently the selective hydrogenation of a wide range of (hetero)aromatic and aliphatic nitriles to the corresponding amines.
January 9, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28044210/cobalt-complexes-as-internal-standards-for-capillary-zone-electrophoresis-mass-spectrometry-studies-in-biological-inorganic-chemistry
#4
Hannah U Holtkamp, Stuart J Morrow, Mario Kubanik, Christian G Hartinger
Run-by-run variations are very common in capillary electrophoretic (CE) separations and cause imprecision in both the migration times and the peak areas. This makes peak and kinetic trend identification difficult and error prone. With the aim to identify suitable standards for CE separations which are compatible with the common detectors UV, ESI-MS, and ICP-MS, the Co(III) complexes [Co(en)3]Cl3, [Co(acac)3] and K[Co(EDTA)] were evaluated as internal standards in the reaction of the anticancer drug cisplatin and guanosine 5'-monophosphate as an example of a classical biological inorganic chemistry experiment...
January 2, 2017: Journal of Biological Inorganic Chemistry: JBIC
https://www.readbyqxmd.com/read/28036181/efficient-synthesis-of-tris-heteroleptic-iridium-iii-complexes-based-on-the-zn-2-promoted-degradation-of-tris-cyclometalated-iridium-iii-complexes-and-their-photophysical-properties
#5
Yuichi Tamura, Yosuke Hisamatsu, Sarvendra Kumar, Taiki Itoh, Kyouhei Sato, Reiko Kuroda, Shin Aoki
We report on the efficient synthesis of tris-heteroleptic iridium (Ir) complexes based on the degradation of tris-cyclometalated Ir complexes (IrL3, L: cyclometalating ligand) in the presence of Brønsted and Lewis acids such as HCl (in 1,4-dioxane), AlCl3, TMSCl, and ZnX2 (X = Br or Cl), which affords the corresponding halogen-bridged Ir dimers (μ-complexes). Tris-cyclometalated Ir complexes containing electron-withdrawing groups such as fluorine, nitro, or CF3 moieties on the ligands were less reactive. This different reactivity was applied to the selective degradation of heteroleptic Ir complexes such as fac-Ir(tpy)2(F2ppy) (fac-12) (tpy: 2-(4'-tolyl)pyridine and F2ppy: 2-(4',6'-difluorophenyl)pyridine), mer-Ir(tpy)2(F2ppy) (mer-12), and mer-Ir(mpiq)2(F2ppy) (mer-15) (mpiq: 1-(4'-methylphenyl)isoquinoline)...
December 30, 2016: Inorganic Chemistry
https://www.readbyqxmd.com/read/28034314/highly-simplified-reddish-orange-phosphorescent-organic-light-emitting-diodes-incorporating-a-novel-carrier-and-exciton-confining-spiro-exciplex-forming-host-for-reduced-efficiency-roll-off
#6
Ting Xu, Ye-Xin Zhang, Bo Wang, Chen-Chao Huang, Imran Murtaza, Hong Meng, Liang-Sheng Liao
A novel exciplex-forming host is applied so as to design highly simplified reddish orange light-emitting diodes (OLEDs) with low driving voltage, high efficiency, and an extraordinarily low efficiency roll-off, by combining N,N-10-triphenyl-10H-spiro [acridine-9,9'-fluoren]-3'-amine (SAFDPA) with 4,7-diphenyl-1,10-phenanthroline (Bphen) doped with trivalent iridium complex bis(2-methyldibenzo[f,h]quinoxaline) (acetylacetonate)iridium(III) (Ir(MDQ)2(acac)). The reddish orange OLEDs achieve a strikingly high power efficiency (PE) of 31...
January 12, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28001382/bifunctional-photocatalysts-for-enantioselective-aerobic-oxidation-of-%C3%AE-ketoesters
#7
Wei Ding, Liang-Qiu Lu, Quan-Quan Zhou, Yi Wei, Jia-Rong Chen, Wen-Jing Xiao
A novel visible-light-responsive chiral ligand has been developed by grafting a triplet state photosensitizer to chiral bisoxazoline ligands. Complexation of this ligand with Ni(acac)2 results in a powerful catalyst for the asymmetric oxidation reaction of β-ketoesters, which uses oxygen or air as the green oxidant and visible light or sunlight as the ideal driving force. Using this protocol, products containing the α-hydroxy-β-dicarbonyl motif are produced in high yields and with excellent enantiopurities...
December 28, 2016: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/27935701/cobalt-catalyzed-6-2-cycloaddition-of-alkynes-with-1-3-5-7-cyclooctatetraene-as-a-key-element-in-the-direct-construction-of-substituted-bicyclo-4-3-1-decanes
#8
Vladimir A D'yakonov, Gulnara N Kadikova, Lilya U Dzhemileva, Guzel F Gazizullina, Ilfir R Ramazanov, Usein M Dzhemilev
A new, effective catalytic system based on Co(acac)2 has been developed for [6 + 2] cycloaddition of terminal alkynes to 1,3,5,7-cyclooctatetraene to give substituted bicyclo[4.2.2]deca-2,4,7,9-tetraenes in high yields (68-85%). The electrophilic activation of double bonds in the bicyclic products with m-CPBA is an efficient method for the synthesis of substituted bicyclo[4.3.1]deca-2,4,8-triene-7,10-diols, which form the key structural moieties of numerous natural biologically active compounds. The structures of the obtained compounds were reliably proven by modern spectral methods and X-ray diffraction...
December 20, 2016: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/27934410/isomeric-diruthenium-complexes-of-a-heterocyclic-and-quinonoid-bridging-ligand-valence-and-spin-alternatives-for-the-metal-ligand-metal-arrangement
#9
Mohd Asif Ansari, Abhishek Mandal, Alexa Paretzki, Katharina Beyer, Wolfgang Kaim, Goutam Kumar Lahiri
5,7,12,14-Tetraazapentacene-6,13-quinone (L) reacts with 2 equiv of [Ru(acac)2(CH3CN)2] to form two linkage isomeric bis(chelate) compounds, [{Ru(II)(acac)2}2(μ-L)], blue 1, with 5,6;12,13 coordination and violet 2 with 5,6;13,14 coordination. The linkage isomers could be separated, structurally characterized in crystals as rac diastereomers (ΔΔ/ΛΛ), and studied by voltammetry (CV, DPV), EPR, and UV-vis-NIR spectroelectrochemistry (meso-1, rac-2). DFT and TD-DFT calculations support the structural and spectroscopic results and suggest a slight energy preference (ΔE = 263 cm(-1)) for the rac-isomer 1 as compared to 2...
December 5, 2016: Inorganic Chemistry
https://www.readbyqxmd.com/read/27910921/bipolar-and-unipolar-silylene-diphenylene-%C3%AF-%C3%AF-conjugated-polymer-route-for-highly-efficient-electrophosphorescence
#10
Yao-Tang Chang, Sunil Sharma, Miao-Ken Hung, Yu-Hsuan Lee, Show-An Chen
σ-π conjugated polymer strategy is proposed for designing electroluminescent host polymers with silylene-diphenylene as the backbone repeat unit giving a high triplet energy (ET = 2.67 eV). By incorporation of high ET (3.0 eV) electron (oxadiazole, OXD) and hole (triphenyl amine, TPA) transport moieties, or TPA alone (in this case, the main chain acts as electron transport channel) as side arms on the silylene, the high ET bipolar and unipolar polymers are formed, allowing a use of iridium green phosphor (Ir(ppy)2(acac), Ir-G) (ET = 2...
December 2, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27878204/continuous-and-ultrathin-platinum-films-on-graphene-using-atomic-layer-deposition-a-combined-computational-and-experimental-study
#11
Bora Karasulu, René H J Vervuurt, Wilhelmus M M Kessels, Ageeth A Bol
Integrating metals and metal oxides with graphene is key in utilizing its extraordinary material properties that are ideal for nanoelectronic and catalyst applications. Atomic layer deposition (ALD) has become a key technique for depositing ultrathin, conformal metal(oxide) films. ALD of metal(oxide) films on graphene, however, remains a genuine challenge due to the chemical inertness of graphene. In this study we address this issue by combining first-principles density functional theory (DFT) simulations with ALD experiments...
December 1, 2016: Nanoscale
https://www.readbyqxmd.com/read/27869699/palladium-ii-acetylacetonato-complexes-with-mesoionic-carbenes-synthesis-structures-and-their-application-in-the-suzuki-miyaura-cross-coupling-reaction
#12
Lara Hettmanczyk, Bianca Schmid, Stephan Hohloch, Biprajit Sarkar
A series of novel palladium(ii) acetylacetonato complexes bearing mesoionic carbenes (MICs) have been synthesized and characterized. The synthesis of the complexes of type (MIC)Pd(acac)I (MIC = 1-mesityl-3-methyl-4-phenyl-1,2,3-triazol-5-ylidene (1), 1,4-(2,4,6-methyl)-phenyl-3-methyl-1,2,3-triazol-5-ylidene (2), 1,4-(2,6-diisopropyl)-phenyl-3-methyl-1,2,3-triazol-5-ylidene (3); acac = acetylacetonato) via direct metalation starting from the corresponding triazolium iodides and palladium(ii) acetylacetonate is described herein...
November 17, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27863110/nickel-catalyzed-facile-2-2-2-cyclotrimerization-of-unactivated-internal-alkynes-to-polysubstituted-benzenes
#13
Fei Xue, Ying Kai Loh, Xiaolu Song, Wei Jie Teo, J Y Darrence Chua, Jin Zhao, T S Andy Hor
A catalytic [2+2+2] cyclotrimerization of unactivated internal alkynes providing cyclotrimerization products in excellent yields with high regioselectivity is described. The transformation is accomplished by using a simple catalytic mixture comprising Ni(acac)2 , an imidazolium salt and a Grignard reagent at room temperature or 60 °C for 20 min or 1 h.
January 3, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/27863095/new-mechanism-for-the-reduction-of-vanadyl-acetylacetonate-to-vanadium-acetylacetonate-for-room-temperature-flow-batteries
#14
Jack S Shamie, Caihong Liu, Leon L Shaw, Vincent L Sprenkle
In this study, a new mechanism for the reduction of vanadyl acetylacetonate, VO(acac)2 , to vanadium acetylacetonate, V(acac)3 , is introduced. V(acac)3 has been studied for use in redox flow batteries (RFBs) for some time; however, contamination by moisture leads to the formation of VO(acac)2 . In previous work, once this transformation occurs, it is no longer reversible because there is a requirement for extreme low potentials for the reduction to occur. Here, we propose that, in the presence of excess acetylacetone (Hacac) and free protons (H(+) ), the reduction can take place between 2...
November 15, 2016: ChemSusChem
https://www.readbyqxmd.com/read/27862462/preparation-of-polyfunctional-organozinc-halides-by-an-inx3-and-licl-catalyzed-zinc-insertion-to-aryl-and-heteroaryl-iodides-and-bromides
#15
Andreas D Benischke, Grégoire Le Corre, Paul Knochel
A catalytic system consisting of InCl3 (3 mol %) and LiCl (30 mol %) allows a convenient preparation of polyfunctional arylzinc halides via the insertion of zinc powder to various aryl iodides in THF at 50 °C in up to 95 % yield. The use of a THF/DMPU (1:1) mixture shortens the reaction rates and allows the preparation of keto-substituted arylzinc reagents. In the presence of In(acac)3 (3 mol %) and LiCl (150 mol %), the zinc insertion to various aryl and heteroaryl bromides proceeds smoothly (50 °C, 2-18 h)...
November 8, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27806086/in-vitro-and-in-vivo-antitumor-activity-of-pt-o-o-acac-%C3%AE-acac-dms-in-malignant-pleural-mesothelioma
#16
Antonella Muscella, Carla Vetrugno, Luca Giulio Cossa, Giovanna Antonaci, Francesco De Nuccio, Sandra Angelica De Pascali, Francesco Paolo Fanizzi, Santo Marsigliante
Malignant pleural mesothelioma (MPM) is an aggressive malignancy highly resistant to chemotherapy. There is an urgent need for effective therapy inasmuch as resistance, intrinsic and acquired, to conventional therapies is common. Among Pt(II) antitumor drugs, [Pt(O,O'-acac)(γ-acac)(DMS)] (Ptac2S) has recently attracted considerable attention due to its strong in vitro and in vivo antiproliferative activity and reduced toxicity. The purpose of this study was to examine the efficacy of Ptac2S treatment in MPM...
2016: PloS One
https://www.readbyqxmd.com/read/27805277/thermochromic-magnetic-ionic-liquids-from-cationic-nickel-ii-complexes-exhibiting-intramolecular-coordination-equilibrium
#17
Xue Lan, Tomoyuki Mochida, Yusuke Funasako, Kazuyuki Takahashi, Takahiro Sakurai, Hitoshi Ohta
Among the various thermochromic materials, liquid thermochromic materials are comparatively rare. To produce functional thermochromic liquids, we have designed ionic liquids based on cationic nickel complexes with ether side chains, [Ni(acac)(Me2 NC2 H4 NR(1) R(2) )]Tf2 N ([1]Tf2 N: R(1) =C3 H6 OEt, R(2) =Me; [2]Tf2 N: R(1) =C3 H6 OMe, R(2) =Me; [3]Tf2 N: R(1) =R(2) =C3 H6 OMe), where acac=acetylacetonate and Tf2 N=(F3 CSO2 )2 N(-) . The side chains (R(1) , R(2) ) can moderately coordinate to the metal center, enabling temperature-dependent coordination equilibria in the liquid state...
November 2, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27748214/electron-beam-induced-deposition-for-atom-probe-tomography-specimen-capping-layers
#18
David R Diercks, Brian P Gorman, Johannes J L Mulders
Six precursors were evaluated for use as in situ electron beam-induced deposition capping layers in the preparation of atom probe tomography specimens with a focus on near-surface features where some of the deposition is retained at the specimen apex. Specimens were prepared by deposition of each precursor onto silicon posts and shaped into sub-70-nm radii needles using a focused ion beam. The utility of the depositions was assessed using several criteria including composition and uniformity, evaporation behavior and evaporation fields, and depth of Ga+ ion penetration...
October 17, 2016: Microscopy and Microanalysis
https://www.readbyqxmd.com/read/27731986/measuring-spin-allowed-and-spin-forbidden-d-d-excitations-in-vanadium-complexes-with-2p3d-resonant-inelastic-x-ray-scattering
#19
Benjamin E Van Kuiken, Anselm W Hahn, Dimitrios Maganas, Serena DeBeer
Spectroscopic probes of the electronic structure of transition metal-containing materials are invaluable to the design of new molecular catalysts and magnetic systems. Herein, we show that 2p3d resonant inelastic X-ray scattering (RIXS) can be used to observe both spin-allowed and (in the V(III) case) spin-forbidden d-d excitation energies in molecular vanadium complexes. The spin-allowed d-d excitation energies determined by 2p3d RIXS are in good agreement with available optical data. In V(acac)3, a previously undetected spin-forbidden singlet state has been observed...
November 7, 2016: Inorganic Chemistry
https://www.readbyqxmd.com/read/27722457/vanadium-iv-and-v-complexes-of-pyrazolone-based-ligands-synthesis-structural-characterization-and-catalytic-applications
#20
Mannar R Maurya, Bithika Sarkar, Fernando Avecilla, Isabel Correia
The ONO donor ligands obtained from the condensation of 4-benzoyl-3-methyl-1-phenyl-2-pyrazoline-5-one (Hbp) with benzoylhydrazide (H2bp-bhz I), furoylhydrazide (H2bp-fah II), nicotinoylhydrazide (H2bp-nah III) and isonicotinoylhydrazide (H2bp-inh IV), upon treatment with [V(IV)O(acac)2], lead to the formation of [V(IV)O(bp-bhz)(H2O)] 1, [V(IV)O(bp-fah)(H2O)] 2, [V(IV)O(bp-nah)(H2O)] 3 and [V(IV)O(bp-inh)(H2O)] 4, respectively. At neutral pH the in situ generated aqueous K[H2V(V)O4] reacts with ligands I and II, forming potassium salts, K(H2O)2[V(V)O2(bp-bhz)] 5 and K(H2O)2[V(V)O2(bp-fah)] 6, while ligands III and IV give neutral complexes, [V(V)O2(Hbp-nah)] 9 and [V(V)O2(Hbp-inh)] 10, respectively...
October 10, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
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