Functionalization and extraction of large fullerenes and carbon-coated metal formed during the synthesis of single wall carbon nanotubes by laser oven, direct current arc, and high-pressure carbon monoxide production methods

Large fullerenes and carbon-coated metal nanoparticles that are formed during the synthesis of carbon nanotubes have been functionalized by the addition of alkyl radicals and isolated by extraction into chloroform. The soluble, functionalized fullerenes have been isolated from raw single-wall carbon nanotube (SWNT) material prepared by laser oven, direct current arc, and high-pressure carbon monoxide production methods. Analyses of the extracted large fullerenes were carried out by thermogravimetric analysis, UV-vis-near-IR, laser desorption ionization mass spectrometry, and high-resolution transmission electron microscopy.     

Synthesis and crystal structure of 2,3,12,13-tetraalkoxy-21, 23-dithiaporphyrins

21,23-Dithiaporphyrins with methoxy, butoxy, octyloxy and dodecyloxy substituents at beta-thiophene carbons were synthesised for the first time and the crystal structure of the butoxy derivative indicated that the substituents at the beta-thiophene carbons induce more planarity in the porphyrin ring.     

Electrochemical synthesis of fully sulfonated n-dopable polyaniline: poly (metanillic acid)

Electrochemical homopolymerization of metanillic acid has been achieved for the first time using a 4:1 acetonitrile-water mixture to get 100% sulfonated polyaniline which is soluble in both organic and aqueous solvents, electrically conducting, and is n-dopable.     

Coupled dynamics of translation and collapse of acoustically driven microbubbles

Pressure gradients drive the motion of microbubbles relative to liquids in which they are suspended. Examples include the hydrostatic pressure due to a gravitational field, and the pressure gradients in a sound field, useful for acoustic levitation. In this paper, the equations describing the coupled dynamics of radial oscillation and translation of a microbubble are given. The formulation is based on a recently derived expression for the hydrodynamic force on a bubble of changing size in an incompressible liquid [J. Magnaudet and D. Legendre, Phys. Fluids 10, 550-556 (1998)]. The complex interaction between radial and translation dynamics is best understood by examination of the added momentum associated with the liquid motion caused by the moving bubble. Translation is maximized when the bubble collapses violently. The new theory for coupled collapse and translation dynamics is compared to past experiments and to previous theories for decoupled translation dynamics. Special attention is paid to bubbles of relevance in biomedical applications.     

Organotin compounds: Toxicology and biomedicinal applications

The toxicology and biomedical aspects and applications of organotin compounds are discussed. Factors affecting toxicity are considered first and then the mechanisms of toxicity are described and assessed. A review of the main biomedical applications then follows, covering biochemical, agricultural and other biocidal uses, and recent developments in the field of anticarcinogenesis.     

Fluorimetric microdetection of tetraphenylboron

Summary One microgram tetraphenylboron may be detected by the fluorescence on treatment with 8-quinolinol.

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Zusammenfassung Ein Mikrogramm Tetraphenylbor kann durch die nach Zusatz von 8-Hydroxychinolin auftretende Fluoreszenz erkannt werden.

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Résumé Il est possible de déceler 1 microgramme de tétraphénylbore par fluorescence après traitement par le quinolinol-8.

     

REDOR with a relative full-echo reference

REDOR and REDOR-like 13C[19F] and 2H[19F] NMR experiments have been performed on lyophilized whole cells of Staphylococcus aureus. The bacteria were grown to maturity on media containing L-[13C(3)]alanine or L-[methyl-d(3)]alanine, and then complexed with the 4-fluorobiphenyl derivative of chloroeremomycin, an analogue of the widely used antibiotic, vancomycin. The position of the 19F of the drug bound in the bacterial cell wall was determined relative to L-alanine 13C and 2H labels in the peptidoglycan peptide stem that was closest to the fluorinated biphenyl moiety of the drug. These determinations were made by dipolar recoupling methods that do not require an absolute measurement of the REDOR full echo (the signal observed without rotor-synchronized dephasing pulses) of the labels in the peptide stem.