Abstract

Dendritic half-sandwich rhodium carborane trimers, [Cp*Rh(1,2-E2-1,2-C2B10H10)]3(tpst) [2a,b; Cp* = .eta.5-C5Me5, tpst = 2,4,6-tris(4-pyridinyl-.kappa.N)methylthio-1,3,5-triazine, E = S, Se] were prepd. by complexation of [Cp*Rh(1,2-E2-1,2-C2B10H10)] with tpst ligand. The complexes 2a,b form toluene solvates in the solid state showing infinitely connected [(2a,b)-(toluene)] helixes. The chains of these supramols. are held together by Cp*-toluene-Cp* .pi.-stacking interactions of two of the three Cp* ligands of the bell-shaped 2a and 2b mols. Unconventional BH.delta.--pyridyl.delta.+ arom. hydrogen bonding enforces the bell-shapes of the mol. units, and the Cp* conformations are expected to induce the supramol. structures.