Abstract The hydrogenation of (CF 3) n GeX 4-n (X= halogen, n= 1–3) with NaBH 4 in an acidic medium has been investigated. Deuteration with NaBD 4 and D 3 PO 4 gave the partially deuterated species CF 3 GeH n D 3-n and (CF 3) 2 GeH n D 2-n in reasonable isotopic purity. The (CF 3) 2 GeHBr was isolated and converted into the halides (CF 3) 2 GeHX (X= F, Cl, I) by treatment with AgX or HX. Insertion of CF 2 into a Ge H bond has ...