pinecone/core-2020-05-10-deduplication huggingface dataset:
The putative monocarboxylate permeases of the yeast Saccharomyces cerevisiae do not transport monocarboxylic acids across the plasma membrane

We have characterized the monocarboxylate permease family of Saccharomyces cerevisiae comprising five proteins. We could not find any evidence that the monocarboxylate transporter-homologous (Mch) proteins of S. cerevisiae are involved in the uptake or secretion of monocarboxylates such as lactate, pyruvate or acetate across the plasma membrane. Ayeast mutant strain deleted for all five MCH genes exhibited no growth defects on monocarboxylic acids as the sole carbon and energy sources. Moreover, the uptake and secretion rates of monocarboxylic acids were indistinguishable from the wildtype strain. Additional deletion of the JEN1 lactate transporter gene completely blocked uptake of lactate and pyruvate. However, uptake of acetate was not even affected after the additional deletion of the gene YHL008c, which had been proposed to code for an acetate transporter. The mch1–5 mutant strain showed strongly reduced biomass yields in aerobic glucose-limited chemostat cultures, pointing to the involvement of Mch transporters in mitochondrial metabolism. Indeed, intracellular localization studies indicated that at least some of the Mch proteins reside in intracellular membranes. However, pyruvate uptake into isolated mitochondria was not affected in the mch1–5 mutant strain. It is concluded that the yeast monocarboxylate transporter-homologous proteins perform other functions than do their mammalian counterparts.União Europeia (UE) – grant BIO4-CT97-2294 (EUROFAN2).Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI-BD/1898/98
Decomposition of hydrogen peroxide in the presence of mixed oxide catalysts

The decompn. of H2O2 in the presence of TiO2-​ZrO2, SiO2-​ZrO2, Al2O3-​ThO2, SiO2-​ThO2, Al2O3-​MoO3, SiO2-​MoO3, Al2O3-​WO3, and SiO2-​WO3 catalysts, ignited 6 hr at 120-​1000°, was studied chem. anal. and kinetically.  Due to the bifunctional nature of these catalyst the effect of the acidic and basic sites on the decompn. was studied by poisoning the sites with Neutral Red and HCl, resp.  Both the acidic and basic sites catalyze the decompn.  The activation energy for the sites is inversely proportional to the acidity and basicity as calcd. from the initial slopes of the rate curves.  The decompn. mechanism in the presence of acidic and basic sites is of similar character.  Only acid sites of pKa < +3.3 and > -​3.0 and basic sites of pKa  10 catalyze the decompn
Platinum(II) mixed ligand complexes with thiourea derivatives, dimethyl sulphoxide and chloride: syntheses, molecular structures, and ESCA data

The platinum(II) mixed ligand complexes [PtCl(L1-6)- (dmso)] with six differently substituted thiourea derivatives HL, R2NC(S)NHC(O)R  (R   Et, R    p-O2N-Ph: HL1; R   Ph, R    p-O2N-Ph: HL2; R   R    Ph: HL3; R   Et, R    o-Cl-Ph: HL4; R2N   EtOC(O)N(CH2CH2)2N, R    Ph: HL5) and Et2NC(S)N  CNH-1-Naph (HL6), as well as the bis(benzoylthioureato-¿O,¿S)- platinum(II) complexes [Pt(L1,2)2] have been synthesized and characterized by elemental analysis, IR, FAB( )-MS, 1H-NMR, 13C-NMR, as well as X-ray structure analysis ([PtCl(L1)(dmso)]
and [PtCl(L3,4)(dmso)]) and ESCA ([PtCl(L1,2)(dmso)] and [Pt(L1,2)2]). The mixed ligand complexes [PtCl(L)(dmso)] have a nearly square-planar coordination at the platinum atoms. After deprotonation,
the thiourea derivatives coordinate bidentately via O and S, DMSO bonds monodentately to the PtII atom via S atom in a cis arrangement with respect to the thiocarbonyl sulphur atom. The Pt S-bonds to the DMSO are significant shorter than those to the thiocarbonyl-S atom. In comparison with the unsubstituted case, electron withdrawing substituents at the phenyl group of the benzoyl moiety of the thioureate (p-NO2, o-Cl) cause a significant elongation of the Pt S(dmso)-bond trans arranged to the benzoyl- O Pt-bond. The ESCA data confirm the found coordination and bonding conditions. The Pt 4f7/2 electron binding energies of the complexes [PtCl(L1,2)(dmso)] are higher than those of the bis(benzoylthioureato)- complexes [Pt(L1,2)2]. This may indicate a withdrawal of electron density from platinum(II) caused by the DMSO ligands.Indexado en ScopusRevisión por pare
Cis-trans Isomerism in Copper(II) Complexes with N-acyl Thiourea Ligands

The N-acyl thiourea complexes bis[N,N-diethyl-N'-(p-nitrobenzoyl)- thioureato]copper(II) (1a,1b) and bis(N,N-diphenyl-N'-benzoylthioureato) copper(II) (2a,2b) crystallize in each case in two modifications. X-ray structural analysis shows that 1a and 1b are cis-trans isomers. This is very unusual for N-acyl thioureato complexes because with exception of one platinum(II) complex up to now only cis complexes have been found. In contrast X-ray structural analysis of both forms 2a and 2b of the other complex shows no cis-trans pair. Both modifications are cis complexes. In solution both isomers of the copper(II) complexes are observable by EPR spectroscopy.Indexado en ScopusRevisión por pare
Substituted bisphosphanylamines as ligands in gold(I) chemistry – synthesis and structures

Dimethyl 5-aminoisophthalate, which is a building block of amino-substituted tetralactam macrocycles, was used as ligand in gold(I) chemistry to form model complexes for macrocyclic gold compounds. Reaction of dimethyl 5-aminoisophthalate with chlorodiphenylphosphine gave the diphosphine compound dimethyl 5-[N,N-bis(diphenylphosphanyl)amino]isophthalate (dmbpaip). This compound can further be reacted with [AuCl(tht)] (tht = tetrahydrothiophene) to give the dinuclear complex [Au(2),Cl(2)(dmbpaip)]. In contrast, treatment of dinbpaip with [Au(tht)(2)]ClO(4) resulted in the ionic compound [Au(2)(dmbpaip)(2)](ClO(4))(2) in which the cation forms an eight-membered Au(2)P(4)N(2) heterocycle. In both gold(I) compounds Au center dot center dot center dot Au interactions are observed. All new compounds were characterized by single-crystal X-ray diffraction
Functionalised tris(pyrazolyl)methane ligands and Re(CO)3 complexes thereof

The synthesis of new tripodal nitrogen ligands derived from tris(pyrazolyl)methane (TpmR, R = H, tBu, Ph in 3-position) is described. After deprotonation of the parent tris(pyrazolyl)methane TpmR, the carbanion reacts readily with ethylene oxide to yield the 3,3,3-tris(3-substituted pyrazolyl)propanol ligands[(3-Rpz)3CCH2CH2OH, R = H, tBu, Ph, 1a-c]. These ligands can be easily derivatised at the alcohol function. Microwave-assisted reactions of these ligands and [Re(CO)5Br] yields the complex [(1a)Re(CO)3]Br (4) in the case of ligand 1a, whereas in the case of the substituted ligands 1b and 1c degradation was observed. The degradation products are identified as [(HpzR)2Re(CO)3Br] [R = tBu (7b), Ph (7c)]. These complexes were also prepared directly from [Re(CO)5Br] and the corresponding pyrazoles by microwave-assisted synthesis. The Re(CO)3 complexes 4 and [(1a)Re(CO)3]OTf (5) are water-soluble. The structures of 5·H2O and [{(pz)3CCH2CH3}Re(CO)3]OTf·1.5H2O·1/2CH3CN (6·1.5H2O·1/2CH3CN) as well as the structure of 7b have been elucidated by X-ray crystallography
Nitridogermanate Nitrides Sr7[GeN4]N2 and Ca7[GeN4]N2

The alkaline earth nitridogermanate nitrides AE7[GeN4]N2 (AE = Ca, Sr) have been synthesized using a Na flux technique in sealed Ta tubes. According to single-crystal X-ray diffraction the isotypic compounds crystallize in space group Pbcn (No. 60) with Z = 4, (Sr7[GeN4]N2: a = 1152.6(2), b = 658.66(13), c = 1383.6(3) pm, V = 1050.5(4) × 106 pm3, R1 = 0.049; Ca7[GeN4]N2: a = 1082.6(2), b = 619.40(12), c = 1312.1(3) pm, V = 879.8(3) × 106 pm3, R1 = 0.016). Owing to the high N/Ge ratio, the compounds contain discrete N3− ions coordinated by six AE2+ besides discrete [GeN4]8− tetrahedrons. One of the AE2+ ion is coordinated by only four N3− ions, which is rather an unusual low coordination number for Sr2+. Together with the isolated [GeN4]8− tetrahedrons, these Sr2+ ions form chains of alternating cation centered edge sharing tetrahedrons. The electronic structure and chemical bonding in Sr7[GeN4]N2 has been analyzed employing linear muffin-tin orbital (LMTO) band structure calculations.
Ammonium Phenylphosphonamidodiselenoates and Phenylphosphonamidodi-selenoic Diamides from the Selenation of Primary and Secondary Amines

The authors are thankful to the University of St Andrews and the Engineering and Physical Science Research Council (EPSRC, U.K.) for financial support.By reacting two equivalents of primary or secondary amines with 2,4-bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide (Woollins' reagent) at room temperature a series of new ammonium phenylphosphonamidodiselenoates 1-7 have been obtained in good to excellent yields (70-99 %). The first metal complex of phenylphosphonamidodiselenoate, the complex of Cd2L4 (L = [Se2PPh(NCH(CH3)(2)](-)) (8) has been prepared from the reaction of diisopropylamine N-isopropyl-P-phenylphosphonamidodiselenoate with Cd(CH3COO)(2) in dichloromethane. Upon heating to 130 degrees C the ammonium phenylphosphonamidodiselenoates lose hydrogen selenide leading to the corresponding phenylphosphonamidodiselenoic diamides 9-11 in almost quantitative yields. The same products 9-11 can also be prepared directly from the reaction of primary amines with Woollins' reagent in refluxing toluene. Three representative X-ray structures are described.PostprintPeer reviewe
Structural synthon approach to predict the possible polytypes of layered double hydroxides

The complete universe of possible polytypes of layered double hydroxides (LDH) is predicted on the basis of symmetry arguments. A single MX 2 (X = OH) layer, also defined as a structural synthon, belongs to the layer group P$\bar{3}$2/m1. These layers can be stacked in such a way as to conserve the unique 3-axis of the layer in the resultant crystal. The different stacking sequences that facilitate symmetry conservation, yield the different possible polytypes of rhombohedral and hexagonal symmetries. More polytypes can be envisaged by including stacking sequences that systematically destroy the principal symmetry elements of the structural synthon. Thereby, stacking sequences that destroy the 3-axis, while retaining the 2-axis, yield possible polytypes of monoclinic symmetry. The nitrate-containing LDH of zinc and aluminum crystallizes in a faulted structure in which, the planar faults are shown to arise on account of stacking sequences whose local symmetry is monoclinic. This approach to polytype prediction expands on an earlier reported method by Bookin and Drits and is very general with important implications for other classes of layered materials. Copyright Â© 2012 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim
Disproportionation of O‐Benzylhydroxylamine Catalyzed by a Ferric Bis‐Picket Fence Porphyrin Complex

Hydroxylamine (NH 2 OH) is an important molecule in biology that serves as an intermediate in the nitrogen cycle, and that can also be utilized as a nitric oxide donor in mammals under certain conditions. In light of this, the interaction of NH 2 OH with hemes in proteins and model systems has gained much attention recently. In this study, we use the more stable, oxygen substituted O‐benzylhydroxylamine (NH 2 OBn) as a model for NH 2 OH. Here, the reactivity of the ferric bis‐picket fence porphyrin complexes [Fe(3, 5‐Me‐BAFP)(ClO 4 )] ( 1 ) and [Fe(3, 5‐Me‐BAFP)(PF 6 )] ( 2 ) (3,5‐Me‐BAFP 2–  = dianion of tetra(2, 6‐bis(3,5‐dimethylphenoxy)phenyl)porphyrin)) with NH 2 OBn is investigated. The product of these reactions is characterized by UV/Vis and EPR spectroscopy and X‐ray crystallography. We found that addition of excess NH 2 OBn to our ferric porphyrin complexes results in reduction of the heme to the ferrous oxidation state. This is followed by disproportionation of additional NH 2 OBn to yield the ferrous complex [Fe(3,5‐Me‐BAFP)(NH 3 ) 2 ] ( 3 ) as the final product. The crystal structure of ( 3 ) constitutes the first structural characterization of a bis‐ammonia complex of a ferrous heme. The stability of this complex may be facilitated by the picket fences of the porphyrin ligand used here
Phase chemistry in the Ca-Mn-Sb-O system at 1160-1250 °C

Phase equilibrium in the Ca-Mn-Sb-O system was studied in air at the temperature range from 1160 to 1250°C and a pseudo-quaternary phase diagram for the system CaO-MnO-Mn2O3-Sb2O5 is presented. The following compounds were discovered: new antimonate Ca 7Sb2O12 with a perovskite-like structure, solid solutions Mn2-xCaxSb2O7 (0 ≤ x ≤ 1.6) with a 3T-weberite structure, and Ca2-xMn xSb2O7 (0 ≤ x ≤ 0.23) with a 2O-weberite structure, as well as solid solutions Ca2Mn1+xSb 1-xO6 with monoclinic (0 ≤ x ≤ 0.67) and orthorhombic (0.75 ≤ x ≤ 1) perovskite structures. The existence of a number of double and ternary oxides and solid solutions on the basis of Sb 5+ and Mn2+, Mn3+, Mn4+ and with mixed manganese valence is confirmed. Copyright © 2013 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim
3d-and 4d-metal(II) complexes of a tris(pyridyl)ethane-derived N-4 ligand – a structural study and reactivity remarks

A series of complexes of the new N-4 chelate ligand L (L = 1-{6-[1,1-bis(pyridin-2-yl) ethyl] pyridin-2-yl}-N, N-dimethylmethanamine) with intermediate to late divalent transition metal ions M was obtained by the reaction between L and the respective chloride salt or similar precursor in methanol: [MCl2L] (M = Mn, Fe, Co, Ni, Zn; Ru) and [CuClL]Cl. The stereochemical characteristics of the chelate ligand were studied by means of single-crystal X-ray diffraction, and quantified on the basis of several geometric parameters, including the tetragonal distortion Sigma and the continuous symmetry measure S(O-h). The overall distortion of the coordination environment is predomi-nantly determined by the steric demand of the central ion, while electronic or other subtler influences essentially contribute to the distortion of the ligand L. Unlike similar complexes, [(MnCl2L)-Cl-II] cannot be oxidized to a manganese(III) complex by dioxygen, hydrogen peroxide, or iodosylbenzene. In [(RuCl2L)-Cl-II], one chlorido ligand can be exchanged against small p-accepting molecules such as acetonitrile or dinitrogen. L offers an environment ideal for small metal ions (0.4-0.6 angstrom), such as low-spin iron(II), which rationalizes the late onset of thermal spin crossover in the complex [(FeL)-L-II(NCS)(2)].DFG, SFB 658, Elementarprozesse in molekularen Schaltern auf Oberfläche
Ionic Liquid assisted Synthesis of Zeolite-TON

This research was funded by EPSRC (grants EP/K005499/1 and EP/K025112/1). The APC was paid through RCUK OA block grant funds.An ionic liquid assisted strategy for the synthesis of zeolitic material is reported. This strategy is a solid state synthetic method and the ionic liquid is employed as structure directing agent. A TON-type zeolite, which contains one-dimensional 10-member-ring, is successfully synthesized with the assistance of the ionic liquid, 1-ethyl-3-methylimidazolium bromide. This finding improves our understanding about the challenge of ionothermally synthesizing siliceous and aluminosilicate zeolites.Publisher PDFPeer reviewe
A Silver(I) Iodide Complex of a Tellurophosphorane

The authors acknowledge the EPSRC and NSERC (Canada) for support.The formation and structural characterization of the first coordination complex of the tellurophosphorane [tBu(H)NP(μ-NtBu)2P(Te)N(H)tBu] are presented. The silver(I) iodide complex {(I)Ag[tBu(H)NP(μ-NtBu)2P(Te)N(H)tBu]3} (2) was isolated from the reaction of [Li(TMEDA)]2[tBuN(Te)P(μ-NtBu)2P(Te)NtBu)] (1) with AgI in toluene and characterized by X-ray analysis and multinuclear NMR spectroscopy. Complex 2 is comprised of three tellurophosphorane ligands coordinated to AgI in a distorted tetrahedral arrangement [102.90(3)–114.51(5)o]. The P=Te bond lengths of 2.3883(13)–2.4043(17) Å in 2 are slightly elongated compared to those in the free ligand.PostprintPeer reviewe
Zinc complexes with guanidine-pyridine hybrid ligands:anion effect and catalytic activity

The guanidine-pyridine ligands DMEGqu, TMGqu, and DMEGpy were reacted with zinc benzoate, zinc acetylacetonate, zinc bromide, zinc tetrafluoroborate, and zinc d,l-lactate in order obtain the corresponding complexes. The compounds were structurally characterized by X-ray crystallography and further characterized by NMR, IR, and MS measurements. All complexes were tested as initiators in the melt polymerization of d,l-lactide and the influence of the anion effect was studied. The bis(chelate) tetrafluoroborate complex 7 exhibited the highest activity
Preparation of Hydride-Ethylene Complexes of Osmium

Ethylene complexes [OsH(eta(2)-CH2=CH2)L-4] Y (1, 2) [L = PPh(OEt)(2), P(OEt)(3); Y = OTf, BPh4] were prepared by reacting the dihydride OsH2L4 first with methyl triflate CH3OTf and then with ethylene (1 atm). Alternatively, the compound [OsH(eta(2)-CH2=CH2){PPh(OEt)(2)}(4)] OTf was prepared by allowing the dinitrogen derivative [OsH(N-2){PPh(OEt)(2)}(4)] OTf to react with ethylene. Acrylo-nitrile CH2=C(H) CN reacts with OsH(OTf)L-4 [L = P(OEt)(3)] to give the complex [OsH{kappa(1)-NCC(H)=CH2}{P(OEt)(3)}(4)]BPh4 (3). The complexes were characterized spectroscopically (IR and H-1, C-13, P-31 NMR) and by X-ray crystal structure determination of the [OsH(eta(2)-CH2=CH2){PPh(OEt)(2)}(4)]BPh4 derivative
An Unusual 3D Zinc-Organic Framework Constructed from Paddle-Wheel-Based Carboxylate Sheets Bridged by Acetate Ions

A zinc-2,6-naphthalenedicarboxylate metal-organic framework,(H2NEt2)[Zn2(AcO)(NDC)2]·nDEF (1) (DEF = N,N-diethylformamide, AcO = acetate), was solvothermally synthesized in the presence of small amounts of acetic acid and characterized by singlecrystal and powder X-ray diffraction and thermogravimetric analysis. Compound 1 is an anionic 3D paddle-wheel MOF, in which the zincnaphthalenedicarboxylate sheets are linked together by bridging acetate ions. Compound 1 exhibits large square channels (13 x 13 Å), which contain DEF molecules and, alternatively, charge-balancing diethylammonium cations in situ generated by the hydrolysis of DEF under the solvothermal conditions used. The anionic host framework of 1 is unstable upon removal of guest DEF molecules suggesting that host-guest hydrogen bond interactions are crucial for maintaining the structural integrity of this compound
Lanthanides Mediated Oxidative Cross Coupling of Benzylalcohol and Various Amines to Form Corresponding Imines

Herein, a new and efficient approach towards the oxidative cross-coupling of benzylalcohol and various aromatic amines to form corresponding imines with high degree conversion (>80 %) and chemo-selectivity using lanthanide salts as pre-catalysts is presented. The catalyzed oxidative cross-coupling reaction using La(NO3)3·6H2O as pre-catalyst displayed a broad substrate scope. The reaction afforded various substituted imines from the reaction of benzylalcohol with ample variety of amines in good yields
A novel copper oxalate, Na2Cu(C2O4)2

The authors thank the Royal Society for the award of a Newton Fellowship (NF140881) to W.Y.A novel copper oxalate Na2Cu(C2O4)2 was synthesized through a hydrothermal method and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic system, P21/n space group with a = 72578(3) Å, b = 5.7711(4) Å, c = 8.6604(8) Å, β = 106.948(9)°. The structure displays a novel stacking pattern of [Cu(C2O4)2]2– units connected through electrostatic attraction by Na+ cations. Structural comparisons are made to related compounds.PostprintPeer reviewe
Numerical Solutions of 2-D Steady Incompressible Flow in a Driven Skewed
  Cavity

The benchmark test case for non-orthogonal grid mesh, the "driven skewed
cavity flow", first introduced by Demirdzic et al. (1992, IJNMF, 15, 329) for
skew angles of alpha=30 and alpha=45, is reintroduced with a more variety of
skew angles. The benchmark problem has non-orthogonal, skewed grid mesh with
skew angle (alpha). The governing 2-D steady incompressible Navier-Stokes
equations in general curvilinear coordinates are solved for the solution of
driven skewed cavity flow with non-orthogonal grid mesh using a numerical
method which is efficient and stable even at extreme skew angles. Highly
accurate numerical solutions of the driven skewed cavity flow, solved using a
fine grid (512x512) mesh, are presented for Reynolds number of 100 and 1000 for
skew angles ranging between 15<alpha<165
A finite element method for the resolution of the Reduced Navier-Stokes/Prandtl equations

A finite element method to solve the bidimensional Reduced Navier-Stokes Prandtl (RNS/P) equations is described. These equations are an asymptotical simplification of the full Navier-Stokes equations, obtained when one dimension of the domain is of one order smaller than the others. These aretherefore of particular interest to describe flows in channels or pipes of small diameter. A low order finite element discretization, based on a piecewise constant approximation of the pressure, is proposed and analyzed. Numerical experiments which consist in fluid flow simulations within a constricted pipe are provided. Comparisons with Navier-Stokes simulations allow to evaluate the performance of prediction of the finite element method, and of the model itself
Water-waves modes trapped in a canal by a body with the rough surface

The problem about a body in a three dimensional infinite channel is
considered in the framework of the theory of linear water-waves. The body has a
rough surface characterized by a small parameter $\epsilon>0$ while the
distance of the body to the water surface is also of order $\epsilon$. Under a
certain symmetry assumption, the accumulation effect for trapped mode
frequencies is established, namely, it is proved that, for any given $d>0$ and
integer $N>0$, there exists $\epsilon(d,N)>0$ such that the problem has at
least $N$ eigenvalues in the interval $(0,d)$ of the continuous spectrum in the
case $\epsilon\in(0,\epsilon(d,N)) $. The corresponding eigenfunctions decay
exponentially at infinity, have finite energy, and imply trapped modes.Comment: 25 pages, 8 figure
Symmetry classes for odd-order tensors

International audienceWe give a complete general answer to the problem, recurrent in continuum mechanics, of determining the number and type of symmetry classes of an odd-order tensor space. This kind of investigation was initiated for the space of elasticity tensors. Since then, this problem has been solved for other kinds of physics such as photoelectricity, piezoelectricity, ﬂexoelectricity, and strain-gradient elasticity. In all the aforementioned papers, the results are obtained after some lengthy computations. In a former contribution we provide general theorems that solve the problem for even-order tensor spaces. In this paper we extend these results to the situation of odd-order tensor spaces. As an illustration of this method, and for the ﬁrst time, the symmetry classes of all odd-order tensors of Mindlin second strain-gradient elasticity are provided
A note on Lorentz-like transformations and superluminal motion

In this extended note a critical discussion of an extension of the Lorentz
transformations for velocities faster than the speed of light given recently by
Hill and Cox is provided. The presented approach reveals the connection between
faster-than-light speeds and the issue of isotropy of space. It is shown if the
relative speed between the two inertial frames $v$ is greater than the speed of
light, the condition of isotropy of space cannot be retained. It further
specifies the respective transformations applying to $-\infty<v<-c$ and
$c<v<+\infty$. It is proved that such Lorentz-like transformations are improper
transformations since the Jacobian is negative. As a consequence, the wave
operator, the light-cone and the volume element are not invariant under such
Lorentz-like transformations. Also it is shown that such Lorentz-like
transformations are not new and already known in the literature.Comment: 9 pages, 1 figur