The spirocyclic germanium thiolates, 4H,4’H-2,2’-spirobi[benzo[d][1,3,2]dithiagermine] (1), 4H,4’H-2,2’-spirobi[benzo[d][1,3,2]oxathiagermine] (2) and 4H,4’H-2,2’-spirobi[benzo[e][1,3,2]oxathiagermine] (3) were synthesized and fully characterized. Compound 3 crystallizes as racemic conglomerate, whereas 1 and 2 give racemates in the solid state. Their reactivity towards twin polymerization (TP) was tested. The studies with regard to proton-assisted TP revealed a significantly reduced reactivity as compared to the recently reported silicon derivative, 4H,4’H-2,2’-spirobi[benzo[d][1,3,2]dioxasiline] (A). DFT−D calculations were performed for 1–3 and the model compound 4H,4’H-2,2’-spirobi[benzo[d][1,3,2]dioxagermine] (4) to evaluate the first reaction step initiating the processes of proton-assisted TP. Compound 4 with germanium bound to four oxygen atoms proved to be the most reactive precursor, but its synthesis failed. As indicated by the DFT−D calculations, compounds 1 and 2 are not suitable for TP. Starting from compound 3 a germanium and sulfur containing organic-inorganic hybrid material was obtained by thermal annealing.