The 1:1 reactions of [((Pr2N)-Pr-t)BP(H)B((NPr2)-Pr-t)PLi . DME] and [(tmp)BP(H)B(tmp)PLi . DME] (tmp = 2,2,5,5-tetramethylpiperidino) with organylhalogermanes have been surveyed, and germyl-substituted diphosphadiboretanes of the type R(2)NBP(H)B(NR(2))PGe(Cl)R’(2)(R(2)N=(Pr2N)-Pr-t, tmp; Ge(Cl)R’(2)=Ge(Cl)Me(2) and G(Cl)Ph(2)) have been isolated and characterized. Subsequent dehydrohalogenation of these compounds with (t)BuLi gave the new bicyclic cage compounds P-2(BNR(2))(2)(GeR’(2)) (R(2)N = tmp, R’ = Ph; R(2)N = tmp, R’ = Me) and/or oligomers [-(R(2)N)BP(H)B(NR(2))PGeR’(2)-](n) (R(2)N = (Pr2N)-Pr-t, R’ = Me; R(2)N = tmp, R’ = Me). In addition, the 2:1 reactions of [(R(2)N)BP(H)B(NR(2))PLi . DME] with R’2GeCl2 have been examined. In one case, the cage compound P-2(BNR(2))(2)GeR’(2)(R(2)N = tmp, R’ = Ph) was obtained while a smaller alkyl group on Ge allowed formation of the bis(diphosphadiboretanyl)germanes [R(2)NBP(H)B(NR(2))P](2)GeR’(2) (R(2)N = (Pr2N)-Pr-t, tmp; R’ = Me). Two P-2(BNR(2))(2)(GeR’(2)). Cr(CO)(5) (complexes R(2)N = tmp, R’ = Ph, Me) were isolated and characterized. The molecular structures of the cage compound P-2(Btmp)(2)GePh(2) and the complexes P-2(Btmp)(2)GeR’(2) . Cr(CO)(5) (R’ = Ph, Me) were determined with single-crystal X-ray diffraction techniques. The structural and spectroscopic features are discussed in relation to those of other P-2(BNR(2))(2)(ER(2)) species.