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https://www.readbyqxmd.com/read/28613317/tuning-the-properties-of-metal-organic-framework-nodes-as-supports-of-single-site-iridium-catalysts-node-modification-by-atomic-layer-deposition-of-aluminium
#1
Dong Yang, Mohammad R Momeni, Hakan Demir, Dale R Pahls, Martino Rimoldi, Timothy C Wang, Omar K Farha, Joseph T Hupp, Christopher J Cramer, Bruce C Gates, Laura Gagliardi
The metal-organic framework NU-1000, with Zr6-oxo, hydroxo, and aqua nodes, was modified by incorporation of hydroxylated Al(iii) ions by ALD-like chemistry with [Al(CH3)2(iso-propoxide)]2 followed by steam (ALD = atomic layer deposition). Al ions were installed to the extent of approximately 7 per node. Single-site iridium diethylene complexes were anchored to the nodes of the modified and unmodified MOFs by reaction with Ir(C2H4)2(acac) (acac = acetylacetonate) and converted to Ir(CO)2 complexes by treatment with CO...
June 14, 2017: Faraday Discussions
https://www.readbyqxmd.com/read/28613074/blue-to-green-emitting-neutral-ir-iii-complexes-bearing-pentafluorosulfanyl-groups-a-combined-experimental-and-theoretical-study
#2
Amlan K Pal, Adam F Henwood, David B Cordes, Alexandra M Z Slawin, Ifor D W Samuel, Eli Zysman-Colman
A structure-property relationship study of neutral heteroleptic (1 and 2, [Ir(C(∧)N)2(L(∧)X)]) and homoleptic (3 and 4, fac-[Ir(C(∧)N)3]) Ir(III) complexes (where L(∧)X = anionic 2,2,6,6-tetramethylheptane-3,5-dionato-κO(3),κO(6) (thd) and C(∧)N = a cyclometalating ligand bearing a pentafluorosulfanyl (-SF5) electron-withdrawing group (EWG) at the C4 (HL1) and C3 (HL2) positions of the phenyl moiety) is presented. These complexes have been fully structurally characterized, including by single-crystal X-ray diffraction, and their electrochemical and optical properties have also been extensively studied...
June 14, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28586216/catalytic-formylation-of-primary-and-secondary-amines-with-co2-and-h2-using-abundant-metal-catalysts
#3
Mohammad A Affan, Philip G Jessop
Catalytic hydrogenation of CO2 is an efficient and selective way to prepare formic acid derivatives, but most of the highly active catalysts used for this purpose require precious metals. In this study, in situ abundant-metal complexes have been evaluated as potential catalysts for CO2 hydrogenation to prepare formamides, including N-formylmorpholine, 2-ethylhexylformamide, and dimethylformamide, from the corresponding amines. From these initial screening results, the most active catalysts for these reactions were found to be MX2/dmpe in situ catalysts (M = Fe(II), Ni(II); X = Cl(-), CH3CO2(-), acac(-); dmpe = 1,2-bis(dimethylphosphino)ethane) in DMSO...
June 6, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28586132/strongly-luminescent-cyclometalated-gold-iii-complexes-supported-by-bidentate-ligands-displaying-intermolecular-interactions-and-tunable-emission-energy
#4
Chi-Ming Che, Kaai Tung Chan, Glenna So Ming Tong, Qingyun Wan, Gang Cheng, Chen Yang
A series of charge-neutral Au(III) complexes, which comprise of dicarbanionic C-deprotonated biphenyl ligand and bidentate ancillary ligands ([Au(C^C)(L^X)]; L = O (1-9) or P (10-11); X = O, N or P), were prepared. All the complexes are emissive in degassed CH2Cl2 solutions and in thin-film samples with Φem up to 18% and 35% respectively, except 5 and 6, which bears (N^O)-type ancillary ligands. Variation of the electronic characteristics of the β-diketonate ancillary ligand was demonstrated to be a viable route for tuning the emission colour from blue-green (peak λem at ca...
June 6, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/28582612/investigation-of-phenols-activity-in-early-stage-oxidation-of-edible-oils-by-electron-paramagnetic-resonance-and-19-f-nmr-spectroscopies-using-novel-lipid-vanadium-complexes-as-radical-initiators
#5
Chryssoula Drouza, Anthi Dieronitou, Ioanna Hadjiadamou, Marios Stylianou
A novel dynamic method for the investigation of the phenols activity in early stage oxidation of edible oils based on the formation of α-tocopheryl radicals initiated by oil-soluble vanadium complexes is developed. Two new vanadium complexes in oxidation states V and IV were synthesized by reacting 2,2'-((2-hydroxyoctadecyl)azanediyl)bis(ethan-1-ol) (C18DEA) with [VO(acac)2] and 1-(bis(pyridin-2-ylmethyl)amino)octadecan-2-ol (C18DPA) with VOCl2. Addition of a solution of either complex in edible oils resulted in the formation of α-tocopheryl radical, which was monitored by electron paramagnetic resonance (EPR) spectroscopy...
June 21, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28537379/molecular-rhodium-complexes-supported-on-the-metal-oxide-like-nodes-of-metal-organic-frameworks-and-on-zeolite-hy-catalysts-for-ethylene-hydrogenation-and-dimerization
#6
Varinia Bernales, Dong Yang, Jun Yu, Gamze Gümüşlü, Christopher J Cramer, Bruce C Gates, Laura Gagliardi
Metal-organic frameworks (MOFs) with nodes consisting of zirconium oxide clusters (Zr6) offer new opportunities as supports for catalysts with well-defined, essentially molecular, structures. We used the precursor Rh(C2H4)2(acac) (acac is acetylacetonate) to anchor Rh(I) complexes to the nodes of the MOF UiO-67 and, for comparison, to the zeolite dealuminated HY (DAY). These were characterized experimentally by measurement of catalytic activities and selectivities for ethylene hydrogenation and dimerization in a once-through flow reactor at 298 K and 1 bar...
May 24, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28500306/plasmonic-purcell-effect-reveals-obliquely-ordered-phosphorescent-emitters-in-organic-leds
#7
R Mac Ciarnain, D Michaelis, T Wehlus, A F Rausch, S Wehrmeister, T D Schmidt, W Brütting, N Danz, A Bräuer, A Tünnermann
The non-isotropic alignment of molecules can increase the interaction efficiency with propagating light fields. This applies to both emissive and absorptive systems and can be exploited for achieving unprecedented efficiencies of organic opto-electronic devices such as organic light-emitting diodes. Optical analysis has revealed certain phosphorescent emitters to align spontaneously in an advantageous orientation. Unfortunately, established approaches only determine an average orientation because emission patterns solely depend on the second moments of the transition dipole vector distribution...
May 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28499214/speciation-of-potential-anti-diabetic-vanadium-complexes-in-real-serum-samples
#8
Daniele Sanna, Valeria Ugone, Maria Serra, Eugenio Garribba
In this work the speciation in real serum samples of five V(IV)O complexes with potential application in the therapy of diabetes was studied through EPR spectroscopy as a function of V concentration (45.4, 90.9 and 454.5μM) and time (0-180min). [VO(dhp)2], [VO(ma)2], [VO(acac)2], [VO(pic)2(H2O)], and [VO(mepic)2], where Hdhp indicates 1,2-dimethyl-3-hydroxy-4(1H)-pyridinone, Hma maltol, Hacac acetylacetone, Hpic picolinic acid, and Hmepic 6-methylpicolinic acid, were examined. The distribution of V(IV)O(2+) among the serum bioligands was calculated from the thermodynamic stability constants in the literature and compared with the experimental results...
April 25, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/28496381/hydrophilic-pt-nanoflowers-synthesis-crystallographic-analysis-and-catalytic-performance
#9
Stefanos Mourdikoudis, Thomas Altantzis, Luis M Liz-Marzán, Sara Bals, Isabel Pastoriza-Santos, Jorge Pérez-Juste
Water-soluble Pt nanoflowers (NFs) were prepared by diethylene glycol-mediated reduction of Pt acetylacetonate (Pt(acac)2) in the presence of polyethylenimine. Advanced electron microscopy analysis showed that the NFs consist of multiple branches with a truncated cubic morphology and different crystallographic orientations. We demonstrate that the nature of the solvent strongly influences the resulting morphology. The catalytic performance of the Pt NFs in 4-nitrophenol reduction was found to be superior to that of other nanoparticle-based catalysts...
May 21, 2016: CrystEngComm
https://www.readbyqxmd.com/read/28449577/cobalt-catalyzed-asymmetric-hydroboration-cyclization-of-1-6-enynes-with-pinacolborane
#10
Songjie Yu, Caizhi Wu, Shaozhong Ge
We report a cobalt-catalyzed asymmetric hydroboration/cyclization of 1,6-enynes with catalysts generated from Co(acac)2 and chiral bisphosphine ligands and activated in situ by reaction with pinacolborane (HBpin). A variety of oxygen-, nitrogen-, and carbon-tethered 1,6-enynes underwent this asymmetric transformation, yielding both alkyl- and vinyl-substituted boronate esters containing chiral tetrahydrofuran, cyclopentane, and pyrrolidine moieties with high to excellent enantioselectivities (86%-99% ee).
May 4, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28435700/redetermination-of-the-crystal-structure-of-di-methyl-bis-2-4-penta-nedionato-1-%C3%AE%C2%BA-2-o-2-o-4-tin-iv
#11
Hans Reuter, Martin Reichelt
The redetermination of the title compound, [Sn(CH3)2(C5H7O2)2] or SnMe2(acac)2, from CCD data recorded at 100 K basically confirms the previous study based on integrated film data recorded at room temperature [Miller & Schlemper (1972 ▸). Inorg. Chem.12, 677-681], but reveals a remarkable shrinkage of the a axis [7.12 (1) > 6.7694 (4) Å]. The mol-ecule belongs to point group Ci with the Sn(IV) atom on a centre of inversion. The Sn(IV) atom shows a slightly distorted octa-hedral coordination sphere with the methyl groups in trans positions and a Sn-C bond length of 2...
April 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28432923/triterpenoid-saponins-from-the-roots-of-spergularia-marginata
#12
David Pertuit, Mustafa Larshini, Malika Aitsidi Brahim, Mohamed Markouk, Anne-Claire Mitaine-Offer, Thomas Paululat, Stéphanie Delemasure, Patrick Dutartre, Marie-Aleth Lacaille-Dubois
Phytochemical investigations of the roots of Spergularia marginata had led to the isolation of four previously undescribed triterpenoid saponins, a known one and one spinasterol glycoside. Their structures were established by extensive NMR and mass spectroscopic techniques as 3-O-β-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L- arabinopyranosyl ester, 3-O-β-D-glucopyranosyl-(1 → 3)-β-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)- α-L-arabinopyranosyl ester, 3-O-β-D-glucopyranosyl-(1 → 4)-3-O-sulfate-β-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl ester, and 3-O-β-D-glucopyranosyl-(1 → 4)-β-D-glucuronopyranosyl 21-O-acetyl acacic acid...
July 2017: Phytochemistry
https://www.readbyqxmd.com/read/28430438/controllable-synthesis-of-lindqvist-alkoxopolyoxovanadate-clusters-as-heterogeneous-catalysts-for-sulfoxidation-of-sulfides
#13
Ji-Kun Li, Jing Dong, Chuan-Ping Wei, Song Yang, Ying-Nan Chi, Yan-Qing Xu, Chang-Wen Hu
Six alkoxohexavanadate-based Cu- or Co-POVs [Cu(dpa)(acac)(H2O)]2[V6O13(OMe)6] (1), [Cu(phen)(acac)(MeOH)]2[V6O13(OMe)6] (2), [Co(dpa)(acac)2]2[V6O13(OMe)6]·2MeOH (3), [Co(phen)(acac)2]2[V6O13(OMe)6] (4), [Cu(dpa)(acac)]2[V(IV)2V(V)4O12(OMe)7] (5), and [Cu(dpa)(acac)(MeOH)]2[V(IV)2V(V)4O11(OMe)8] (6) (POV = polyoxovanadate; dpa = 2,2'-dipyridine amine; phen = 1,10-phenanthroline; acac = acetylacetone anion) have been synthesized by controlling the reaction conditions and characterized by single-crystal X-ray diffraction and powder X-ray diffraction analyses, FT-IR spectroscopy, element analyses, and X-ray photoelectron spectroscopy...
April 21, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28424495/significance-of-genetic-polymorphisms-in-long-non-coding-rna-ac079767-4-in-tuberculosis-susceptibility-and-clinical-phenotype-in-western-chinese-han-population
#14
Zhenzhen Zhao, Mei Zhang, Jun Ying, Xuejiao Hu, Jingya Zhang, Yanhong Zhou, Yi Zhou, Xingbo Song, Binwu Ying
Recent studies have implicated long non-coding RNA, AC079767.4, as a highly susceptible gene in tuberculosis. The aim of the study was to preliminarily explore the possible association of single nucleotide polymorphisms (SNPs) in AC079767.4 gene with clinical phenotypes and TB susceptibility in Western Chinese Han population. The improved multiplex ligation detection reaction (iMLDR) method was employed to genotype 4 SNPs in AC079767.4 in 554 tuberculosis patients and 561 healthy individuals. In subgroup analysis, only the C allele for rs12477677 was associated with the decreased susceptibility to pulmonary TB with a p-value of 0...
April 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28400150/effects-of-acetylacetone-on-the-photoconversion-of-pharmaceuticals-in-natural-and-pure-waters
#15
Guoyang Zhang, Bingdang Wu, Shujuan Zhang
Acetylacetone (AcAc) has proven to be a potent photo-activator in the degradation of color compounds. The effects of AcAc on the photochemical conversion of five colorless pharmaceuticals were for the first time investigated in both pure and natural waters with the UV/H2O2 process as a reference. In most cases, AcAc played a similar role to H2O2. For example, AcAc accelerated the photodecomposition of carbamazepine, oxytetracycline, and tetracycline in pure water. Meanwhile, the toxicity of tetracyclines and carbamazepine were reduced to a similar extent to that in the UV/H2O2 process...
April 8, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28388072/tuning-the-excimer-emission-of-amphiphilic-platinum-ii-complexes-mediated-by-phospholipid-vesicles
#16
Marsel Z Shafikov, Alfiya F Suleymanova, Dmitry N Kozhevnikov, Burkhard König
Two new amphiphilic platinum(II) complexes, [Pt(2-(4-fluorophenyl)-5-(4-dodecyloxyphenyl)pyridine) (acac)] (Pt-1) and [Pt(2-(4-dodecyloxyphenyl)-5-(thien-2-yl)-c-cyclopentenepyridine) (acac)] (Pt-2), where acac is acetylacetonate, were synthesized and characterized. Apart from conventional phosphorescence of single molecules (ME-monomer emission), complexes Pt-1 and Pt-2 also exhibit excimer emission (EE) when embedded into phospholipid vesicles, that is assigned to emissive Pt-Pt excimers. The EE intensity in vesicular media appeared to depend on the viscosity of the vesicles and the concentration of the embedded complex...
April 7, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28352910/coordination-abilities-of-polycyano-anions-in-the-solid-state-coordination-geometries-and-d-d-transition-energies-of-mixed-ligand-solvatochromic-copper-ii-complexes-with-b-cn-4-c-cn-3-and-n-cn-2-anions
#17
Xue Lan, Takumi Tominaga, Tomoyuki Mochida
B(CN)4(-), C(CN)3(-), and N(CN)2(-) are highly versatile polycyano anions that produce various functional compounds. To investigate the coordination abilities of these anions in the solid state quantitatively, we synthesized mixed-ligand Cu(ii) complexes: [Cu(R-acac)(tmen)X] (X = polycyano anion, R-acac = acetylacetonate or butyl-acetylacetonate, tmen = tetramethylethylenediamine). The coordination abilities of the anions, increasing in the order B(CN)4(-) < C(CN)3(-) < N(CN)2(-), result in a decrease in the d-d transition energies of the complexes and the shortening of the axial coordination distance...
April 11, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28338686/an-iron-catalysed-c-c-bond-forming-spirocyclization-cascade-providing-sustainable-access-to-new-3d-heterocyclic-frameworks
#18
Kirsty Adams, Anthony K Ball, James Birkett, Lee Brown, Ben Chappell, Duncan M Gill, P K Tony Lo, Nathan J Patmore, Craig R Rice, James Ryan, Piotr Raubo, Joseph B Sweeney
Heterocyclic architectures offer powerful creative possibilities to a range of chemistry end-users. This is particularly true of heterocycles containing a high proportion of sp(3)-carbon atoms, which confer precise spatial definition upon chemical probes, drug substances, chiral monomers and the like. Nonetheless, simple catalytic routes to new heterocyclic cores are infrequently reported, and methods making use of biomass-accessible starting materials are also rare. Here, we demonstrate a new method allowing rapid entry to spirocyclic bis-heterocycles, in which inexpensive iron(III) catalysts mediate a highly stereoselective C-C bond-forming cyclization cascade reaction using (2-halo)aryl ethers and amines constructed using feedstock chemicals readily available from plant sources...
April 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28327758/a-dy4-single-molecule-magnet-and-its-gd-iii-tb-iii-ho-iii-and-er-iii-analogues-encapsulated-by-an-8-hydroxyquinoline-schiff-base-derivative-and-%C3%AE-diketonate-coligand
#19
Hong-Ling Gao, Xiao-Pu Zhou, Yan-Xia Bi, Hai-Yun Shen, Wen-Min Wang, Ni-Ni Wang, Yi-Xin Chang, Ru-Xia Zhang, Jian-Zhong Cui
Five new tetranuclear complexes based on an 8-hydroxyquinoline Schiff base derivative and the β-diketone coligand, [Ln4(acac)4L6(μ3-OH)2]·CH3CN·0.5CH2Cl2 (Ln = Gd (1), Tb (2), Dy (3), Ho (4) and Er (5); HL = 5-(benzylidene)amino-8-hydroxyquinoline; acac = acetylacetonate) have been synthesized, and structurally and magnetically characterized. Complexes 1-5 have similar tetranuclear structures. Each Ln(III) ion is eight coordinated and its coordination polyhedra can be described as being in a distorted square-antiprismatic geometry...
March 22, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28317955/prediction-of-strong-o-h-m-hydrogen-bonding-between-water-and-square-planar-ir-and-rh-complexes
#20
G V Janjić, M D Milosavljević, D Ž Veljković, S D Zarić
Intermolecular O-H/M interactions, between a water molecule and square-planar acac complexes ([M(acac)L2]), with different types of L ligands (en, H2O, CO, CN(-), and OH(-)) and different types of metal atoms (Ir(i), Rh(i), Pt(ii), and Pd(ii)) were studied by high level ab initio calculations. Among the studied neutral complexes, the [Pd(acac)(CN)(CO)] complex forms the weakest interaction, -0.62 kcal mol(-1), while the [Ir(acac)(en)] complex forms the strongest interaction, -9.83 kcal mol(-1), which is remarkably stronger than the conventional hydrogen bond between two water molecules (-4...
March 20, 2017: Physical Chemistry Chemical Physics: PCCP
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