Nanoscale architectures for molecular electronics: Vibrational spectroscopy and structure of solid hexa-n-dodecyl-hexa-peri-hexabenzocoronene.

Selected for Virtual Journal of Nanoscale Science & Technology (API, APS) issue October 24, 2005 The solid columnar discotic and liquid-crystalline phases formed by hexan- dodecyl-hexa-peri-hexabenzocoronene HBC-C12 have been investigated by IR and Raman vibrational spectroscopies. IR spectra clearly show the two phase transitions at 42 and at 107 °C already reported in literature and allow us to understand the conformational modifications of the n-alkyl chains that take place through the transitions. Thanks to the collected data, we propose a model of the structure of HBC-C12 in the solid-crystalline phase below 42 °C which includes the structure of the alkyl chains. This model is also confirmed by dichroic infrared microscopy measurements on highly oriented samples.