Condensation Reaction of 1,2,3,4-Tetrahydro-1,10-phenanthroline and Formaldehyde: Synthesis and Crystal Structures of Bis(1,2,3,4-tetrahydro-1,10-phenanthroline-6-yl)methane and Its p-Toluenesulfonate Salt

Abstract

A new heterocyclic compound, bis(1,2,3,4-tetrahydro-1,10-phenanthroline-6-yl) methane (1), was obtained by the condensation reaction of 1,2,3,4-tetrahydro-1,10-phenanthroline (tphen) and formaldehyde (HCHO). The p-toluenesulfonate salt of 1, (ptsa)₂ · (1H₂) (2, ptsaH = p-toluenesulfonic acid), is also synthesized and characterized. Cystal structures of 1 and 2 are determined by X-ray single crystal diffraction. The molecules of 1 form a 1D helix supramolecular chain by weak N−H···N hydrogen bonds, while in crystal 2, the 1H₂²⁺ cations and ptsa^- anions are alternately connected by strong N−H···O hydrogen bonds and generate a 1D zigzag supramolecular chain. The result also proves that the condensation reaction of tphen can provide its C6 condensation product with high regioselectivity.