Synthesis and crystal structure of 1,1'-bis-{[4-(pyridin-2-yl)-1,2,3-triazol-1-yl]meth-yl}ferrocene, and its complexation with CuI.

The title compound, [Fe(C13H11N4)2], was synthesized starting from 1,1'-ferro-cene-di-carb-oxy-lic acid in a three-step reaction sequence. The di-carb-oxy-lic acid was reduced to 1,1'-ferrocenedi-methanol using LiAlH4 and subsequently converted to 1,1'-bis-(azido-meth-yl)ferrocene in the presence of NaN3. The diazide was treated with 2-ethynyl-pyridine under 'click' conditions to give the title compound in 75% yield. The FeII center lies on an inversion center in the crystal. The two pyridyl-triazole wings are oriented in an anti conformation and positioned exo from the FeII center. In the solid state, the mol-ecules inter-act by C-H⋯N, C-H⋯π, and π-π inter-actions. The complexation of the ligand with [Cu(CH3CN)4](PF6) gives a tetra-nuclear dimeric complex.