Synthesis of 2‑Ureido-4-ferrocenyl Pyrimidine Guests. Investigation of Complementary Molecular Recognition of 2,6-Diaminopyridine

Novel 2-ureido-4-ferrocenylpyrimidines
have been synthesized from
iodoferrocene by a three-step reaction sequence. XRD analysis and
spectroscopic data support the presence of an intramolecular hydrogen
bond between a nitrogen atom of the pyrimidine ring and an NH group
of the urea moiety. Both theoretical calculations and NMR investigations
prove the existence of two isomeric forms in solution, both of which
can form hydrogen bonds with an appropriate guest via an acceptor–donor–acceptor
bonding pattern. Complexation with 2,6-diaminopyridine can be proved
either by NMR spectroscopy or by electrochemical measurements.