A Molecular Triangle as a Precursor Toward the Assembly of a Jar-Shaped Metallasupramolecule

The reaction of Re-2(CO)(10) and 1,1'-carbonyldiimidazole in toluene afforded the molecular triangle [Re-3(mu(2)-Im)(3)(CO)(12)] (1; Im = imidazolate). This air-stable complex 1 acted as a precursor, which could then be further transformed into the complex [{Re(CO)(3)}(3)(mu(2)-Im)(3)(mu(3)-L)] (2.; L = 1,3,5-tris(benzimidazol-1-ylmethyl)-2,4,6-trimethylbenzene) upon reaction with the flexible ligand L under solvothermal conditions. Complex 2 can also be produced directly in a one-pot reaction from Re-2(CO)(10), 1,1'-carbonyldiimidazole, and the flexible ligand L. A single-crystal X-ray diffraction analysis showed that compound 1 has a triangular-shaped structure, which is the smallest rhenium triangle known, as of this writing. Complex 2 adopted a jar-shaped structure. The photophysical properties of complexes 1 and 2 were studied.