Addition of PPh2Cl and TI[PF6] to CH2Cl2 solutions of [N(PPh3)(2)][6,6,6-(CO)(3)-closo-6,1-FeCB8H9] (1) affords the isomeric B-substituted species [6,6,6-(CO)(3)-n-(PHPh2)-closo-6,1-FeCB8H8] [n = 7 (2a) or 10 (2b)]. Deprotonation (NaH) of the phosphine ligand in 2a, with subsequent addition of [IrCl(CO)(PPh3)(2)] and TI[PF6], yields the neutral, zwitterionic complex [6,6,6-(CO)(3)-4,7-mu-{Ir(H)(CO)(PPh3)(2)PPh2}-closo-6,1-FeCB8H7](3), which contains a B-P-Ir-B ring. Alternatively, deprotonation using NEt3, followed by addition of HC CCH2Br, affords [6,6,6-(CO)(3)-7-(PPh2C CMe)-closo-6,1-FeCB8H8] (4). Addition of [CO2(CO)(8)] to CH2Cl2 solutions of the latter gives [6,6,6-(CO)(3)-7-(PPh2-{(mu-eta(2):eta(2)-C CMe)Co-2(CO)6})-closo-6,1-FeCB8H8] (5), which contains a {C2Co2} tetrahedron. In the absence of added substrates, deprotonation of the PHPh2 group in compounds 2, followed by reaction of the resulting anions with CH2Cl2 solvent, affords [6,6,6-(CO)(3)-n-(PPh2CH2Cl)-closo-6,1-FeCB8H8] [n = 7 (6a) or 10 (6b)] plus [6,6-(CO)(2)-6,7-mu-{PPh2CH2PPh2}-closo-6,1-FeCB8H8] (7, formed from 2a), of which the latter species possesses an intramolecular B-P-C-P-Fe ring. Addition of Me3NO to CH2Cl2 solutions of 2a causes loss of an Fe-bound CO ligand and formation of [6,6-(CO)(2)-6,7-mu-{NMe2CH2PPh2}-closo-6,1 -FeCB8H8] (8), which incorporates a B-P-C-N-Fe ring. A similar reaction in the presence of ligands L yields [6,6-(CO)(2)-6-L-7-(PPh2CH2Cl)-closo-6,1-FeCB8H8] [L = PEt3 (9) or CNBut (10)], in addition to 8.