Synthesis and characterization of ferrocenyl stannanes and polyferrocenyl stannanes

A novel polymer polybis(dimethyl stannyl)ferrocene was synthesized through both metal catalyzed intermolecular dehydrogenative condensation and ring-opening polymerization. This polymer was the first evidence of a dibridged polyferrocenyl stannane, and was found to be of low to moderate molecular weight by gel permation chromatography and 1H NMR spectroscopy. This polymer displayed extensive electronic communication observed previously synthesized monobridged ferrocenyl stannane polymers. The first tristanna-bridged 3.3]ferrocenophane was discovered through an amine coupling of a tin amine, and 1,1’bis(dimethyl stannyl) ferrocene. The [3.3]ferrocenophane displayed a strong interaction between connected ferrocenes despite the large distance, (8.49 Å) between Fe centers. Finally, a new and improved synthesis of 1,1,2,2-tetramethyldistanna-[2]ferrocenophane was found. This metal catalyzed intramolecular dehydrogenative coupling employs Pd2(dba)3 as a catalyst and yields 90% product. All products were characterized where possible 1H, 13C, and 119Sn NMR and UV-Visible spectrocopy, as well as through cyclic voltammetry and DFT modeling.