ABSTRACT
C(60).C(8)H(8) and C(70).C(8)H(8) are prototypes of rotor-stator cocrystals. We present infrared and Raman spectra of these materials and show how the rotor-stator nature is reflected in their vibrational properties. We measured the vibrational spectra of the polymer phases poly(C(60)C(8)H(8)) and poly(C(70)C(8)H(8)) resulting from a solid-state reaction occurring on heating. On the basis of the spectra, we propose a connection pattern for the fullerene in poly(C(60)C(8)H(8)), where the symmetry of the C(60) molecule is D(2h). On illuminating the C(60).C(8)H(8) cocrystal with green or blue light, a photochemical reaction was observed leading to a product similar to that of the thermal polymerization.
ABSTRACT
In this study we present direct sidewall functionalization of single-walled nanotubes, carried out via two different dissolving metal reduction methods. A modified Birch reduction scheme and a novel synthetic route were applied to form carbanion complexes on the surface of the nanotubes in liquid NH3 and tetrahydrofuran, respectively. The carbanion complex was reacted with a series of alkyl and aryl halogenides resulting in the corresponding SWNT derivatives. We determined the chemical composition and the thermal stability of the functionalized nanotubes by thermogravimetry/mass spectrometry and pyrolysis-gas chromatography. Characteristic decomposition peaks, observed in the temperature range of 350-600 degrees C, suggest the formation of covalent derivatives upon functionalization that is also supported by Raman spectroscopic studies. The influence of the functional groups and the type of nanotubes on the thermal stability, as well as the relationship between the functional group content and the intensity of the Raman D peak are discussed.
Subject(s)
Metals/chemistry , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Carbon/chemistry , Catalysis , Chromatography, Gas , Mass Spectrometry , Models, Chemical , Molecular Structure , Nanotubes/chemistry , TemperatureABSTRACT
Electron spin resonance and ab initio electronic structure calculations show an intricate relation between molecular rotation and chemical bonding in the dilute solid solution. The unpaired electron of C59N is delocalized over several C60 molecules above 700 K, while at lower temperatures it remains localized within short range. The data suggest that below 350 K rigid C59N-C60 heterodimers are formed in thermodynamic equilibrium with dissociated rotating molecules. The structural fluctuations between heterodimers and dissociated molecules are accompanied by simultaneous electron spin transfer between C60 and C59N molecules. The calculation confirms that in the C59N-C60 heterodimer the spin density resides mostly on the C60 moiety, while it is almost entirely on C59N in the dissociated case.
ABSTRACT
Single crystals of a linear cycloadduct conducting polymer, (KC(60))n, have been grown that are a few tenths of a millimeter in length. Partial oxidation under toluene transformed these crystals into bundles of fibers. The degree of polymerization exceeded 100,000.
ABSTRACT
During 1983 an unusual high incidence of listeriosis in man was observed in parts of Lower Saxony. 24 strains of Listeria monocytogenes--all serotyp 4b--were isolated from 10 newborn infants, 3 children and 11 adults suffering from meningitis and sepsis. All of the affected newborns and children recovered with antibiotic therapy.
Subject(s)
Listeriosis/epidemiology , Adolescent , Adult , Aged , Child , Child, Preschool , Cross Infection/epidemiology , Cross-Sectional Studies , Female , Germany, West , Humans , Infant , Infant, Newborn , Male , Meningitis, Listeria/epidemiology , Middle Aged , Pregnancy , Risk , Sepsis/epidemiologyABSTRACT
The absorbing and precipitating capacity of leucocyte nuclear suspensions derived from conserved blood of various blood groups was examined with anti-A-, anti-B-, anti-H, anti-M-, anti-N-, and anti-CDE-, and anti-D-sera as well as with anti-AHP- and Evonymus-extracts. Nuclei of blood group A absorbed anti-A, but not anti-B; nuclei of blood group B absorbed anti-B, but not anti-A. Nuclei of blood group 0 absorbed anti-H, but neither anti-A nor anti-B. Anti-M-, anti-N-, anti-CDE-, and anti-D-sera showed no absorption effect after incubation with leucocyte nuclei of corresponding blood groups. A nuclei were strongly precipitated by anti-AHP; B- and 0-nuclei were markedly precipitated by Evonymus-extract. B- and 0-nuclei showed only a weak precipitation with anti-AHP-extract; A-nuclei were only slightly precipitated by Evonymus-extract. Hence, leucocyte nuclei possess blood group specific properties, which, according to the present studies, are limited to certain blood group systems.
