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- Item1,1,2,2-Tetra-kis(1,3-benzoxazol-2-yl)ethene(2011) Hagos T.K.; Nogai S.D.; Dobrzaska L.; Cronje S.; Raubenheimer H.G.The title compound, C30H16N4O4, reveals crystallographic and mol-ecular symmetry and accordingly the asymmetric unit comprises one half-molecule. The dihedral angle between the planes of the two geminal benzoxazole rings is 74.39 (5)°. The packing features weak C - H⋯N and π-π interactions [centroid-centroid distance = 3.652 (1) Å].
- Item1,1,2,2-Tetrakis(1,3-benzothiazol-2-yl)ethene chloroform disolvate(2010) Hagos T.K.; Nogai S.D.; Dobrzanska L.; Cronje S.; Raubenheimer H.G.The asymmetric unit of the title solvate, C30H 16N4S4·2CHCl3, contains one half-molecule of tetrakis(2-benzothiazolyl)ethene, the complete molecule being generated by inversion symmetry, and one molecule of chloroform. Pairs of the benzothiazole rings attached to the same carbon atom are almost perpendicular to each other, with an angle between planes of 85.74 (4)°. In the crystal, weak C-H⋯N and C-H⋯Cl interactions generate a three-dimensional network.
- Item1,2,3-Trihydroxybenzene-pyrimidine (1/1)(2005) Dobrzanska L.In the title molecular co-crystal, C6H6O 3⋯H4N2, symmetry-related O-H⋯N hydrogen bonds with O⋯N distances of 2.790 (3) and 2.818 (2) Å link molecules of 1,2,3-trihydroxybenzene and pyrimidine to form 18-membered rings which, in turn, are constituents of infinite chains created by O-H⋯O hydrogen bonds between hydroxy groups in positions 1 and 2 of neighbouring 1,2,3-trihydroxybenzene molecules. The infinite chains are further stacked in stepped columns by offset π-π interactions, and are linked by C-H⋯π interactions, resulting in a herringbone pattern. © 2005 International Union of Crystallography Printed in Great Britain - all rights reserved.
- Item1,3-Benzothia-zolium tetra-chlorido-aurate(III) tetra-hydro-furan solvate(2009) Hagos T.K.; Nogai S.D.; Dobrzaska L.; Cronje S.; Raubenheimer H.G.In the crystal structure of the title ionic compound (C7H 6NS)[AuCl4]·C4H8O, the [AuCl4]- anion shows a typical square-planar geometry. Numerous weak C - H⋯Cl hydrogen bonds between [AuCl4] - and the 1,3-benzothia-zolium units form layers comprised of 24-membered rings in which hydrogen-bonded tetra-hydro-furan (THF) solvent mol-ecules are accommodated. C - H⋯Cl inter-actions between THF and [AuCl4]- from adjacent layers result in bilayers. These are further stabilized by π-π inter-actions between the thia-zole and benzene rings [centroid-centroid distance = 3.971 (3) Å], resulting in the formation of a three-dimensional supra-molecular assembly.
- Item1,3-Dimesitylimidazolidinium tetra-chloridogold(III) dichloro-methane solvate(2008) Hagos T.K.; Nogai S.D.; Dobrzaska L.; Cronje S.The title ionic compound, (C21H27N2)[AuCl4]·CH2Cl2, was obtained from the reaction of 1,3-dimesitylimidazolidinium chloride with t-BuOK and a solution of AuCl3 in tetra-hydro-furan. In the crystal structure, numerous weak C - H⋯Cl hydrogen bonds form double layers parallel to (100), which are further stabilized by π-π inter-actions between mesitylene rings [centroid-centroid distance = 4.308 (4) Å], resulting in the formation of a three-dimensional supra-molecular assembly.
- Item{1,5,9-Tris[(2S)-2-hydroxypropyl]-1,5,9-triazacyclododecane}zinc(II) dinitrate monohydrate(2010) Strasser C.E.; Sumani J.E.Y.; Raubenheimer H.G.; Luckay R.C.In the title compound, [Zn(C18H39N3O 3)](NO3)2·H2O, the coordination geometry around the central ZnII atom is distorted octa-hedral. The hydroxyl groups in the macrocyclic ligand and water mol-ecules are engaged in O - H⋯O hydrogen bonding, which forms two-dimensional corrugated sheets comprising 34-membered rings. Neighbouring sheets are connected by C - H⋯O inter-actions.
- Item1000-580Ma crustal evolution in the northern Arabian-Nubian Shield revealed by U-Pb-Hf of detrital zircons from late Neoproterozoic sediments (Elat area, Israel)(2012) Morag N.; Avigad D.; Gerdes A.; Harlavan Y.The final stages in the evolution of the Arabian-Nubian Shield (ANS) during the late Neoproterozoic include the deposition of sub-aerial volcano-sedimentary sequence above exhumed deep-seated plutonic-metamorphic rocks. In southern Israel the sediments in this sequence, known collectively as the Elat conglomerate unit, consist primarily of immature polymictic conglomerates whose composition closely reflects their underlying basement. U-Pb dating and Hf isotopic analysis of single zircons from two samples of the Elat conglomerate is used here to gain a complementary perspective on crustal evolution processes in the northern ANS. The U-Pb age spectra of the detrital zircons bear evidence for two major magmatic cycles separated by a lull; early island-arc magmatism occurred at 880-760Ma and peaked at ∼800Ma, whereas post-collisional granitoids and volcanics invaded the amalgamated arc crust between 660 and 580Ma and peaked at 610-630Ma. Integration with previously published data from Sinai suggests the aforementioned igneous cycles and the intervening lull are of regional significance. Although island-arc igneous activity in the ANS ranged mostly between 880 and 760Ma, the occurrence of detrital zircons with strongly positive e{open} Hf(t) values and U-Pb ages of up to 1.0Ga in the Elat conglomerate suggests that island-arc magmatism in the northern ANS started in the early Tonian, earlier than previously recognized. The youngest zircons in the Elat conglomerate constrain its deposition age to ∼580. Ma. No younger U-Pb zircon ages were obtained for crystalline rocks in this region, our data thus indicates that 580. Ma marks the cessation of igneous activity in the northern ANS. The great majority of detrital zircons in the Elat conglomerate display positive e{open} Hf(t) values, in line with the overall juvenile character of the Shield. Nonetheless, the relatively wide range of e{open} Hf(t) values in zircons representing island-arc magmatism (between +3.6 and +11.6), and the presence of zircons with pre-Neoproterozoic ages and/or negative e{open} Hf(t) values, suggest some contamination of the arc magmas by an older crustal component. The e{open} Hf(t) values in zircons representing the younger, post-collisional magmas are all positive (between +4.9 and 9.2) and resemble those in the preceding arc-derived zircons. This feature is consistent with both reworking of mafic island-arc crust and contribution from mantle-derived melts during the post-collisional stage. Thus, it cannot be deciphered whether the 1000-580Ma igneous activity in the northern ANS represents continuous juvenile crustal addition from the mantle, or subsequent recycling of early-formed arc crust during a later post-collisional phase. © 2012 Elsevier B.V.
- Item16α-Hydroxyprogesterone: Origin, biosynthesis and receptor interaction(2011) Storbeck K.-H.; Swart P.; Africander D.; Conradie R.; Louw R.; Swart A.C.
- Item195Pt NMR and DFT computational methods as tools towards the understanding of speciation and hydration/solvation of [PtX6] 2- (X = Cl-, Br-) anions in solution(2006) Koch K.R.; Burger M.R.; Kramer J.; Westra A.N.195Pt NMR together with DFT calculations and MD simulations, offer a powerful toolkit with which to probe the hydration shells of the [PtCl6]2- anions, which may lead to a more profound understanding of the solute-solvent interactions of such complexes. © The Royal Society of Chemistry 2006.
- Item195Pt NMR isotopologue and isotopomer distributions of [PtCln(H2O)6 - N]4 - n (n = 6,5,4) species as a fingerprint for unambiguous assignment of isotopic stereoisomers(2008) Gerber W.J.; Murray P.; Koch K.R.A detailed analysis of the 35Cl/37Cl isotope shifts induced in the 128.8 MHz 195Pt NMR resonances of [PtCl n(H2O)6 - n]4 - n complexes (n = 6,5,4) in acidic solution at 293 K, shows that the unique isotopologue and isotopomer distribution displayed by the resolved 195Pt resonances, serve as a fingerprint for the unambiguous identification and assignment of the isotopic stereoisomers of [PtCl5(H2O)]- and cis/trans-[PtCl4(H2O)2]. © 2008 The Royal Society of Chemistry.
- Item1H-MRS in autism spectrum disorders: A systematic meta-analysis(2012) Ipser J.C.; Syal S.; Bentley J.; Adnams C.M.; Steyn B.; Stein D.J.We conducted a systematic review and metaanalysis of proton magnetic resonance spectroscopy (1HMRS) studies comparing autism spectrum disorder (ASD) patients with healthy controls, with the aim of profiling ASD-associated changes in the metabolites N-acetylaspartate (NAA) and Creatine (Cr). Meta-regression models of NAA and Cr levels were employed, using data from 20 eligible studies (N0852), to investigate age-dependent differences in both global brain and region-specific metabolite levels, while controlling for measurementmethod (Cr-ratio versus absolute concentrations). Decreased NAA concentrations that were specific to children were found for whole-brain grey and white matter. In addition, a significant decrease in NAA was evident across age categories in the parietal cortex, the cerebellum, and the anterior cingulate cortex. Higher levels of Cr were observed for ASD adults than children in global grey matter, with specific increases for adults in the temporal lobe and decreased Cr in the occipital lobe in children. No differences were found for either NAA or Cr in the frontal lobes. These data provide some evidence that ASD is characterized by age-dependent fluctuations in metabolite levels across the whole brain and at the level of specific regions thought to underlie ASD-associated behavioural and affective deficits. Differences in Cr as a function of age and brain region suggests caution in the interpretation of Cr-based ratio measures of metabolites. Despite efforts to control for sources of heterogeneity, considerable variability in metabolite levels was observed in frontal and temporal regions, warranting further investigation. © Springer Science+Business Media, LLC 2012.
- Item2,2'-Dimethyl-3,3'-(p-phenylenedimethylene)-diimidazol-1-ium dibromide(2005) Dobrzanska L.In the centrosymmetric title compound, C16H20N 42-·Br2+, the Br counter-ions form hydrogen bonds with protonated imidazole groups. Neighbouring cations are held together via weak C-H⋯Br hydrogen bonds and offset π-π interactions, resulting in the formation of a three-dimensional structure. © 2005 International Union of Crystallography Printed in Great Britain - all rights reserved.
- Item2,2′-(butane-1,4-diyl)dibenzimidazolium dichloride dihydrate(2006) Dobrzanska L.; Lloyd G.O.In the title compound, C18H24Cl2N 4O2, a quarternary adduct consisting of two water molecules and two chloride ions binds the centrosymmetric 2,2′-(butane-1, 4-diyl)dibenzimidazolium cations into two-dimensional hydrogen-bonded layers. © 2006 International Union of Crystallography All rights reserved.
- Item2,2′-(Sulfanediyldimethylene)bis-(1,3-benzothiazole)(2011) Strasser C.E.; De Jongh L.-A.; Raubenheimer H.G.; Cronje S.In the title compound, C16H12N2S 3, the two benzothiazole groups are oriented differently with respect to the -CH2- groups, one being approximately staggered and one nearly eclipsed. A sulfur-π interaction of 3.3627 (11) Å is observed between the bridging thio-ether S atom and a thiazole ring. The crystal packing is further stabilized by intermolecular C - H⋯N and C - H⋯π interactions.
- Item2,4,6-Tris(bromomethyl)-1,3,5-trimethylbenzene(2007) Murray P.; Willans C.; Bredenkamp M.W.; Gertenbach J.-A.The title compound, C12H15Br3, has been synthesized and its structure is reported here. The bulky Br atoms are accommodated above and below the plane of the benzene ring. © 2007 International Union of Crystallography. All rights reserved.
- Item2,4-Bis(methoxymethyl)-1,3,5-trimethylbenzene(2006) Dobrzanska L.; Heydenrych G.The title compound, C13H20O2, displays polar ordering owing to intermolecular C-H⋯O hydrogen bonds that link the molecules to form a three-dimensional network. A twofold rotation axis bisects the ring, passing through the unsubstituted C atom, the para-C atom and C of the attached methyl group. © 2006 International Union of Crystallography. All rights reserved.
- Item2-({4-[(1H-Imidazol-2-ylsulfanyl)methyl]-2,5-dimethylbenzyl}sulfanyl) -1H-imidazole(2010) Applewhite M.J.; Potts S.V.The title compound, C16H18N4S2, was prepared by the substitution reaction of two equivalents of 2-mercaptoimidazole for every bromine substituent of 1,4-bis-(bromo-meth-yl)-2, 5-dimethyl-benzene. The mol-ecule is located on a crystallographic centre of inversion and therefore adopts a trans configuration with regards to the orientation of the two sulfur atoms. An inter-molecular N - H⋯N hydrogen bond forms layers of mol-ecules parallel to ( 03). The dihedral angle between the central and terminal rings is 174.8 (2)°.
- Item2-Methyl-1,3-benzoxazol-4-yl diphenylphosphinate(2011) Kleinhans D.J.The title compound, C20H16NO3P, was synthesized by the addition of diphenylphosphine chloride to a tetrahydrofuran solution of Et3N and 2-methyl-1,3-benzoxazol-4-ol at 233 K. In the molecule, the almost planar (r.m.s. deviation = 0.010 Å) benzoxazole moiety is attached to the slightly distorted tetrahedral P atom [C -P -C -C torsion angle = 132.20 (18)°]. The crystal structure does not exhibit any significant intermolecular interactions.
- Item(2051) Proposal to conserve the name Talaromyces over Lasioderma (Ascomycota)(2012) Seifert K.A.; Frisvad J.C.; Houbraken J.; Llimona X.; Peterson S.W.; Samson R.A.; Visagie C.M.[No abstract available]
- Item250kW transformer-less voltage dip compensator(1999) Visser A.J.; Mouton H.du T.Voltage dips cause serious problems for sensitive equipment in industrial applications. The possibility of applying a transformer-less dip compensator is investigated as a cost-effective solution to overcome this hazard. This is achieved by means of a power electronic multi-level converter placed in series with the supply.