Fluor

Ohne Zusammenfassung     

Dihapto-acyl derivatives of ruthenium(II). Preparation and structure of Ru[η2-C(O)CH3] I(CO)(PPh3)2 and Ru[η2-C(O)p-tolyl]I(C0) (PPh3) 2

Reaction between Ru(CO)₂(PPh₃)₃ and MeHgI yields Ru[η²-C(O)CH₃]I(CO)(PPh₃)₂ which in solution exists mainly as RuCH₃I(CO)₂(PPh₃)₂ and crystal structure determination of Ru[η²-C(O)CH₃]I(CO)(PPh₃)₂ and previously described Ru[η²-C(O)p-tolyl]I(CO) (PPh₃)₂ confirms that in the solid state both molecules contain dihapto-acyl ligands.     

The tris(triphenylphosphine)osmium zerovalent complexes Os(CO)2(PPh3)3, .Os(CO)(CNR)(PPh3)3, Os(CO)(CS)(PPh3)3, Os(CS)(cNR)(PPh3)3 and derived compounds

Detailed procedures for the syntheses of Os(CO)₂(PPh₃)₃, Os(CO)(CNR)-(PPh₃)₃ (R = p-tolyl), Os(CO)(CS)(PPh₃)₃ and Os(CS)(CNR)(PPh₃)₃, together with the derived complexes Os(CO)₂(CS)(PPh₃)₂, Os(CO)(CS)(CNR)(PPh₃)₂, Os(η²-C₂H₄)(CO)(CNR)(PPh₃)₂, Os(η²-C₂H₄)(CO)(CS)(PPh₃)₂, Os(η²CS₂)(CO)₂-(PPh₃)₂, Os(η²CS₂)(CO)(CS)(PPh₃)₂, Os(η²-CS₂)(CO)(CNR)(PPh₃)₂, Os(η²PhC₂Ph)(CO)₂(PPh₃)₂ and OsH(C2Ph)(CO)₂(PPh₃)₂ are described.     

A Broad-Spectrum Synthesis of Tetravinylethylenes

The first general synthesis of compounds of the tetravinylethylene (TVE) family is reported. Ramirez-type dibromo-olefination of readily accessible penta-1,4-dien-3-ones generates 3,3-dibromo[3]dendralenes, which undergo twofold Negishi, Suzuki–Miyaura or Mizoroki–Heck reactions with a wide variety of olefinic coupling partners. This route delivers a broad range of unsymmetrically substituted tetravinylethylenes with up to three different alkenyl substituents attached to the central C=C bond. The extensive scope of the approach is demonstrated by the preparation of the first higher order oligo-alkenic through-conjugated/cross-conjugated hybrid compounds. An unsymmetrically substituted TVE is shown to undergo a domino electrocyclization–cycloaddition with high site-selectivity and diastereoselectivity, thereby demonstrating the substantial synthetic potential of substituted TVEs for controlled, rapid structural complexity generation.     

Synthesis and Structures of cis- and trans-[Os(Bcat)(aryl)(CO)2(PPh3)2]: Compounds of Relevance to the Metal-Catalyzed Hydroboration Reaction and the Metal-Mediated Borylation of Arenes

Support for key steps of the mechanism for the transition metal catalyzed hydroboration reaction is provided by the characterization and reactions of 1 , a cis-(boryl)(aryl) complex of osmium(II ). This compound readily eliminates o-tolylBcat to give the osmium(0) intermediate 2 , which in the presence of HBcat reestablishes the osmium–boron bond by forming 3 . R=o-tolyl, H₂cat=catechol=1,2-(HO)₂C₆H₄.     

Red in Estonian popular belief and folk costume

A visit by one of the authors to Estonia, and the discovery that the term ‘red’ was used locally for the colour ‘orange’, led to a detailed study of the colour red in Estonian belief and culture. The study is reported here, together with an interpretation of the red/orange substitution based on Berlin and Kay's model of colour term development in language.     

Two-color electrophoretic immunoassay for simultaneous measurement of insulin and glucagon content in islets of Langerhans

A multianalyte CE competitive immunoassay using two-color detection was developed to measure insulin and glucagon in islets of Langerhans. Insulin was quantified with FITC-insulin (Ins*) and anti-insulin antibodies (Ins Ab) and glucagon was quantified with Cy5-glucagon (Glu*) and anti-glucagon antibodies (Glu Ab). A 3 mW Ar(+) laser at 488 nm and a 25 mW laser diode at 635 nm were used to excite FITC and Cy5, respectively. Fluorescence was split with a half-silvered mirror and passed through a 520 +/- 20 nm bandpass filter or a 663 nm longpass filter for the detection of insulin and glucagon, respectively. The two-color detection format enabled independent quantitation of both analytes even with concentrations of insulin immunoassay reagents 20-fold higher than glucagon reagents. Simultaneous calibration curves were generated and used to determine insulin and glucagon content in islets of Langerhans. Amounts of insulin and glucagon were 56.6 +/- 3.2 and 1.0 +/- 0.5 ng/islet, respectively. LODs were 7 nM insulin and 3 nM glucagon. The assay will be applicable to fast monitoring of multiple peptides secreted from islets of Langerhans and can be applied to other systems for the quantitation of multiple analytes with large differences in concentrations.     

Transport and separation of biomolecular cargo on paramagnetic colloidal particles in a magnetic ratchet

Paramagnetic particles in a magnetic ratchet potential were transported in discrete steps in an aqueous solution on the surface of a magnetic garnet film. The proposed technique allows the simultaneously controlled, dispersion-free movement of an ensemble of paramagnetic particles across the surface. External magnetic modulations were used to transport the particles in a defined direction, and a current reversal upon changing the size of the particles was used to separate particles having different diameters. Doublets consisting of a larger and a smaller particle functionalized with complimentary oligonucleotides and bound via Watson-Crick base pairing were separated after melting the double stranded DNA.