Synthesis of rhenium-based M3L3L′-type metallacycle from benzimidazole and flexible tri(benzimidazole) ligands

The reaction of Re2(CO)10 with benzimidazole (H-L) and 1,3,5-tris(benzimidazol-1-ylmethyl)-2,4,6-trimethylbenzene (L′) gives a heteroleptic cycle [(fac-Re(CO)3)3(L)3(L′)] (1). The supramolecular metallacycle 1 adopts a capped metallacalix[3]arene structure.