Search results for "Ryle"

Sulfur-incorporating cyclotriveratrylene analogues: the synthesis of cyclotrithioguaiacylene.

2011

Cyclotriguaiacylene 1 is the universal precursor of cryptophanes, and represents an important intermediate for the preparation of functionalized cavitands of the cyclotriveratrylene family. Its thio analogue (cyclotrithioguaiacylene 3) was synthesized by two different routes, involving either the Newman-Kwart or the Pummerer rearrangement. The latter, performed starting from a trisulfoxide precursor, produced a purer compound in higher overall yield.

Generation of Stereocenters Around a C3-Symmetric Cyclotriveratrylene Crown

2012

The oxidation of racemic methylthio-substituted C3-symmetric cyclotriveratrylene (CTV) 2 produces the corresponding trisulfoxides 3 as follows. Oxidation with m-chloroperoxybenzoic acid (m-CPBA) in dichloromethane leads to the formation of a distribution of the four possible diastereomers that is relatively close to the statistical outcome, in which the C3-symmetric stereoisomers are the minor species. In contrast, the optically active Davis reagent [oxaziridine (+)-4] in carbon tetrachloride at room temperature leads to a biased (73 %) distribution in favor of the C3-symmetric MRRR/PSSS diastereomer of 3 with 56 % ee (PSSS enantiomer according to the model of Davis). Interestingly, when th…

Photoblinking and photobleaching of rylene diimide dyes.

2010

We investigate photoblinking and photobleaching of perylene diimide (PDI) and its higher homologue terrylene diimide (TDI). Single molecule fluorescence trajectories of the dye molecules embedded in PMMA under ambient conditions exhibit "on"-"off" blinking in the time range from ms to s. Due to the limited statistics of individual trajectories we construct ensemble distributions of "on" and "off" times which follow power laws with similar power law coefficients (m(on) ≈ 1.18, m(off) ≈ 1.31). The blinking is attributed to reversible formation of radical cations which are presumably created by electron transfer from higher excited triplet states T(n) of the molecules to acceptor levels in the…

Heteropodinae: Transfers and Synonymies (Arachnida: Araneae: Sparassidae)

2002

New taxonomical and systematical results concerning the subfamily Heteropodinae are presented. The following new synyonyms are recognized: Adrastis Simon 1880, Panaretus Simon 1880, Parhedrus Simon 1887 are junior synyonyms of Heteropoda Latreille 1804. Adrastis atomaria Simon 1880 =Heteropoda boiei (Doleschall 1859); Parhedrus fasciatus Reimoser 1927=Heteropoda ocyalina (Simon 1887); Heteropoda holzi Strand 1907, Tortula gloriosa Simon 1880, Tortula simoni Karsch 1884, Holconia beccarii Thorell 1890, Isopeda beccarii malangana Strand 1907=Heteropoda lunula (Doleschall 1857); Olios freycineti Walckenaer 1837, Olios albifrons Lucas 1852, Helicopis maderiana Thorell 1875, Palystes ledleyi Hog…

CCDC 232005: Experimental Crystal Structure Determination

2004

Related Article: E.Coronado, J.R.Galan-Mascaros, C.Gimenez-Saiz, C.J.Gomez-Garcia, E.Martinez-Ferrero, M.Almeida, E.B.Lopes, S.C.Capelli, R.M.Llusar|2004|J.Mater.Chem.|14|1867|doi:10.1039/b402630f

Separating the Mechanism-Based and Off-Target Actions of Cholesteryl Ester Transfer Protein Inhibitors With CETP Gene Polymorphisms

2010

Background— Cholesteryl ester transfer protein (CETP) inhibitors raise high-density lipoprotein (HDL) cholesterol, but torcetrapib, the first-in-class inhibitor tested in a large outcome trial, caused an unexpected blood pressure elevation and increased cardiovascular events. Whether the hypertensive effect resulted from CETP inhibition or an off-target action of torcetrapib has been debated. We hypothesized that common single-nucleotide polymorphisms in the CETP gene could help distinguish mechanism-based from off-target actions of CETP inhibitors to inform on the validity of CETP as a therapeutic target. Methods and Results— We compared the effect of CETP single-nucleotide polymorphisms …

Autonomia del linguistico ed eclettismo metodologico

2009

Application of molecular imprinted polymers for selective solid phase extraction of bisphenol A

2016

Selective molecularly imprinted polymers (MIPs) with bisphenol A as template were synthesized using the non-covalent imprinting approach. MIPs were prepared using thermally initiated polymerization with 1,1’-azobis(cyclohexanecarbonitryle) (ACHN) as initiator and ethylene glycol dimethacrylate (EDMA) as a cross-linking agent. The tested functional monomers included methacrylic acid, acrylamide, and 4-vinylpyridine. The selectivity of the BPA-MIP for the solid phase extraction of bisphenol A was tested in samples containing other related alkylphenols. The polymers prepared in acetonitrile using methacrylic acid or acrylamide as monomer showed the highest selectivity towards target analyte (t…