VIBRATIONAL-SPECTRA OF CUBANE AND 4 OF ITS DEUTERATED DERIVATIVES

Vibrational spectra are reported for cubane, cubanc-d1, syw-cubane-d2, sym-cubane-d6, and cubane-d8. Infrared spectra are from 400 to 3600 cm−1 for CS2 and CCI4 solutions, and for a solid deposited from the vapor at ~100 K. Ramanspectra are for the same solutions and for the polycrystalline solid at room temperature. Vibrational assignments have beenmade for all the fundamentals of all five compounds, 120 modes in all. The fortuitous crystal structure of cubane and cubane-d8 was an important aid. Of the 18 fundamentals of cubane, only one or two are not certain. The spectra show almost no effectof the severe bond angle strain. Also there are no low molecular modes; the lowest for cubane is 617 cm−1. © 1979, American Chemical Society. All rights reserved.