Bromodiborane, B2H5Br, was prepared by mixing bromine and diborane. The resulting unstable B2H5Br was separated from its equilibrium mixture by standard fractionation techniques in a high vacuum system. The infrared spectrum in the 14000 to 1250 cm region was obtained for B2H5Br in both the gaseous state and as a frozen solid film. Frequency assignments were made by correlation with B2H5D and B2H5CH3 assignments. The preparation of chlorodiborane, B2H5Cl, was attempted by mixing BCl3 and B2H6. All attempts to separate B2H5Cl from its equilibrium mixture were unsuccessful as were all attempts to observe its formation by absorption spectrum of the gas mixture.