The crystal structure of benzenediazonium tetrafluoroborate, C6H5N2+•BF4−1

Benzenediazonium tetrafluoroborate, C 6 H 5 N 2 + •BF 4 − , crystallizes in space group P2 1 /a with unit cell dimensions a = 17.347(2), b = 8.396(1), c = 5.685(1) Å, β = 92.14(1)°, Z = 4. The structure was solved by direct phasing methods using the program SHELX 76. The parameters were refined by full-matrix least-squares to a final R = 0.063 for 1346 observed reflections. The bond lengths and angles agree very well with those of Rømming for benzenediazonium chloride. The C—N and N≡N bond lengths are 1.415(3) and 1.083(3) Å, respectively, and the bonds of the benzene ring do not show any significant differences as they vary from 1.371(5) to 1.383(4) Å. There are three [Formula: see text] close contacts of ≤ 2.84 Å and the positive charge appears to be shared between the nitrogen atoms.