9-(Pyrrolidinium-1-yl)-9-boranuidabi-cyclo-[3.3.1]nona-ne.

The title compound, C 12 H 24 BN, is an adduct formed from 9-borabi-cyclo-[3.3.1]nonane (9-BBN) and pyrrolidine. It crystallizes in the triclinic space group P with three mol-ecules in the asymmetric unit, one of which has disorder of the pyrrolidine ring. The B-N bond lengths are between 1.631 (2) and 1.641 (2) Å. The boron and nitro-gen atoms are bound to one hydrogen atom each. These hydrogen atoms are in anti-periplanar orientation. Both six-membered rings of the 9-BBN unit are in a chair conformation in all three mol-ecules. Differences between the three crystallographic independent mol-ecules are found in the five-membered rings of the pyrrolidine unit. These adopt different twisted and envelope conformations.