Infrared spectroscopic investigation of higher diamondoids

Attenuated total reflection Fourier transform infrared spectra are recorded for a number of diamond molecules (or higher diamondoids) in the spectral range between 650 and 3000 cm−1. Molecules studied are diamantane, triamantane, [121]tetramantane, [123]tetramantane, [1(2,3)4]pentamantane, [12(3)4]pentamantane, 3-methyl-[1(2,3)4]pentamantane, and [12312]hexamantane (cyclohexamantane). Spectral trends are clearly recognized throughout the spectra revealing the general fingerprint of this class of molecules. In general, the spectra show good agreement with density functional theory calculations at the B3LYP/D95(d,p) level of theory.