Functionalized oxathiacrown macrocycles: Synthesis, characterization and coordination to palladium(II), ruthenium(II) and copper(I)

• Two oxathiacrown macrocycles having an exocyclic double bond were prepared.
• They display S- and O-donor atoms able to be coordinated to transition metals.
• Discrete exo-coordinated complex with two S-bindings was obtained with palladium.
• An additional coordination with O-donor atom was observed with ruthenium.
• The coordination to copper leads to double and single-stranded coordination polymers.

New oxathiacrown macrocycles with exocyclic double bond 1 and 2 were synthesized and characterized. Their coordination behavior with soft transition metals is investigated. Reaction of 1 with PdCl2 afforded exo-coordinated complex 3 with the two S-donor atoms. With RuCl2(PPh3)3, the macrocyclic ligand 1 is bonded through three donor atoms (two sulfur and one oxygen) to the ruthenium center in a facial coordination mode. By contrast, double and single-stranded one dimensional (1D) coordination polymers were obtained by reaction of CuBr with macrocycles 1 and 2. All complexes were spectroscopically characterized and their structure was secured by X-ray diffraction analysis.

Discrete complexes of palladium(II) or ruthenium(II) with a mixed sulfur–oxygen macrocyclic ligand were characterized, exploiting either two sulfur atoms in the case of palladium or one oxygen and two sulfur atoms in the case of ruthenium. By contrast, CuBr reacts with the same ligand to form a 1D coordination polymer.Figure optionsDownload as PowerPoint slide