Synthesis, characterization, spectroscopic study, and catalytic behavior of ruthenium(II) o-phenanthroline complex with dipicolinate

Abstract

A new dipicolinate complex of Ru(II), cis-[Ru(phen)₂dipic] · 9.5H₂O (1), where dipic is dipicolinate or pyridine-2,6-dicarboxylate and phen is 1,10-phenanthroline, has been synthesized and characterized by elemental analysis, spectroscopic (IR, UV-Vis), cyclic voltammetry, and single-crystal X-ray diffraction. ORTEP drawing of cis-[Ru(phen)₂dipic] · 9.5H₂O shows that the coordination geometry around Ru(II) is a distorted octahedron. It crystallizes in the triclinic system, with space group P 1, a = 10.4633(2) Å, b = 13.6332(4) Å, c = 13.6637(4) Å, α = 67.516(3)°, β = 69.757(2)°, γ = 77.201(2)°, V = 1680.74(8) ų, Z = 2, and R _int = 0.0311. In 1, two phen are bidentate N,N′ ligands. The Ru(II) in 1 is bonded to dipicolinate through pyridine nitrogen and one oxygen of carboxylate groups, thus pyridine-2,6-dicarboxylate is a bidentate N,O ligand. Efficient and selective oxidation of alcohols with NaIO₄ as oxidant was conducted by this complex catalyst in CH₃OH/H₂O as solvents under air at room temperature.

Keywords:

• Ruthenium(II)
• 1,10-Phenanthroline
• Dipicolinate
• X-ray crystallography
• Synthesis

Acknowledgments

We gratefully acknowledge the Research Council of the Islamic Azad Univercity-Neyriz Branch for the financial support.