High-resolution infrared studies of Al(BH4)3 and Al(BD4)3

High-resolution Fourier-transform infrared spectra of Al(BH4)3 and Al(BD4)3 were obtained for low-pressure samples at room temperature. Results indicated only wide vibrational bands with no resolved rotational structure. The BH bridge stretching and the BH2 deformation areas were also analyzed at 0.001/cm resolution through tunable infrared diode laser spectroscopy for samples cooled to about 10 K in a multipass, slit expansion. Results showed near continua, with much more crowding than predicted by nonrigid rotor simulations based on boron isotopic shifts.