Polycarborane-substituted molecules [Cp*Rh{E2C2(B10H10)}](3)(tpst) [E = S (2a), Se (2b)] were synthesized and characterized. 2a and 2b form toluene solvates in the solid state showing infinitely connected [(2a,b)-(toluene)](infinity) helices. The chains of these supramolecules are held together by Cp*-toluene-Cp* pi-stacking interactions of two of the three Cp* ligands of the bell-shaped 2a and 2b molecules. Unconventional BH delta--pyridyl(delta+) aromatic hydrogen bonding enforces the bell-shapes of the molecular units, and the Cp* conformations are expected to induce the supramolecular structures.