ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Spectroscopic and magnetic evidence of coordination properties of bioactive diethyl (pyridin-4-ylmethyl)phosphate ligand with chloride transition-metal ions

Urszula Kalinowska-Lis, Bogumiła Żurowska, and Justyn Ochocki

Department of Bioinorganic Chemistry, Faculty of Pharmacy, Medical University, 1 Muszyńskiego St., 90-151 Lodz, Poland

E-mail: urszula.kalinowska-lis@umed.lodz.pl

Abstract: A series of five chloride coordination compounds of diethyl (pyridin-4-ylmethyl)phosphate (4-pmOpe) ligand, i.e. [CuCl₂(4-pmOpe)₂], [NiCl₂(4-pmOpe)₄], [CoCl₂(4-pmOpe)], [ZnCl₂(4-pmOpe)₂], and [CdCl₂(4-pmOpe)₂], was prepared and studied. Stoichiometry and stereochemistry of the compounds was confirmed by spectroscopic and magnetic studies as well as by elemental analyses. The 4-pmOpe ligand has a capacity to coordinate to metal ions by means of phosphoryl oxygen and/or nitrogen of pyridine atoms. In Cu(II), Ni(II), and Zn(II) compounds, 4-pmOpe adopts the monodentate coordination mode, bonding metal centers through the pyridine nitrogen atom only. On the contrary, in Co(II) and Cd(II) compounds, 4-pmOpe acts as N,O-bridging ligand forming polynuclear structures. Magnetic studies (1.8–300 K) indicate mononuclear structure of the Co(II) and Ni(II) compounds and suggest existence of a very weak exchange coupling between metal centers in crystal lattice.

Keywords: transition-metal(II) complexes – N-heterocyclic phosphate – spectroscopy – magnetism

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-011-0056-8

Chemical Papers 65 (5) 660–666 (2011)