A NEW FUNCTIONALIZED OLIGOPYRIDINE LIGAND CONTAINING FERROCENE AS A BALL-BEARING SPACER FOR METALLOSUPRAMOLECULAR CHEMISTRY

A new supramolecular building-block in which a ferrocene moiety has been used as a spacer linking two terpyridyl units has been prepared. The new multidentate ligand 1,1'-bis(2,2':6',2''-terpyridin-4'-yl)ferrocene (tft) incorporates two tridentate metal-binding domains. The ligand has been synthesised from ferrocene-1,1'-dicarbaldehyde and 2-acetylpyridine in a two-stage procedure. The reaction of ferrocene-1,1'-dicarbaldehyde with 2-acetylpyridine yields the bis-chalcone 1,1'-[3-oxo-3-(2-pyridyl)prop-2-en-yl]ferrocene which has been structurally characterised: monoclinic, space group P2(1)/c (No. 14) with a = 13.126(3), b = 10.470(2), c = 15.642(3) angstrom, beta = 111.62(3)-degrees and Z = 4, R1 0.052 (F > 4sigma(F), for 1611 reflections) and R2 0.125 (all data). The cyclopentadienyl rings of the ferrocene are eclipsed and the two 2,2':6',2''-terpyridinyl moieties are in a stacked coplanar conformation. The reaction of this chalcone with N-[1-oxo-2-(2-pyridyl)ethyl]pyridinium iodide and ammonium acetate yielded the new ligand as an orange solid which was structurally characterised: monoclinic, space group P2(1)/c (No. 14), a = 13.268(3), b = 18.147(4), c = 12.458(2) angstrom, beta = 90.73(3)-degrees and Z = 4, R1 0.077 (F > 4sigma(F), for 2041 reflections) and R2 0.217 (all data). Once again, the cyclopentadienyl rings of the ferrocene are eclipsed and the two 2,2':6',2''-terpyridinyl moieties are in a stacked coplanar conformation.