Depending on the molar ratio by reaction of [n-Bu4N](2)[ReBr6] With the Lewis acid BBr3 in dichloromethane the bioctahedral complexes [n-Bu4N](2)[Re2Br10] and [n-Bu4N][Re2Br9] are formed. The X-ray structure determination on (Ph3PNPPh3)(2)[Re2Br10] (monoclinic, space group C 2/c, a = 20.007(4), b = 15.456(5), c = 24.695(4) Angstrom, beta = 107.53(2)degrees, Z = 4) reveals a centrosymmetric edge-sharing complex anion with approximate D-2h symmetry and mean terminal and bridging Re-Br bond lengths of 2.453 (equatorial), 2.482 (axial) and 2.591 Angstrom, respectively, and a Re-Re distance of 3.880 Angstrom. (Ph4P)[Re2Br9] (triclinic, space group 
, a = 11.062(2), b = 12.430(3), c = 13.163(5) Angstrom, alpha = 72.94(2), beta = 68.47(2), gamma = 82.09(2)degrees, Z = 2) contains a confacial bioctahedral anion with nearly D-3h symmetry and mean terminal and bridging Re-Br distances of 2.460 and 2.536 Angstrom, respectively, and a Re-Re distance of 2.780 Angstrom.