Capillary filling of single-walled carbon nanotubes with ferrocene in an organic solvent

Capillary reactions of single-walled carbon nanotubes have been investigated both in ferrocene-saturated acetone and in ferrocene vapor. The encapsulations of ferrocene are observed as subsequent growth of inner shell tubes. From Raman spectroscopy we show that the filling yield is about ten times higher with the vapor filling. The inner tube - outer tube pair distributions are identical for both converted samples and different to the one grown from the fullerene precursor. The largest assigned inner shell tube from ferrocene is (11,0), which is not available from the fullerene precursor. This result is attributed to the catalytic growth mechanism enabling a wide diameter range of inner shell tubes. The solvent based filling provides for a quick analysis of possible molecule guest - nanotube host pairs with a moderate filling factor. [GRAPHICS] Inner tube grows from encapsulated ferrocenes. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim