Synthesis and spectroscopy of diethyl (pyridinylmethyl)phosphates and their palladium (II) complexes: X-ray crystal structures of Pd(II) complexes

The synthesis of diethyl (pyridin-2-, -3-, -4-ylmethyl)phosphate (2-pmOpe, 3-pmOpe, 4-pmOpe) ligands and their palladium (II) complexes of general formula trans-[PdCl2L2] (L = 2-pmOpe, 3-pmOpe,4-pmOpe) has been described. Pyridine phosphate derivatives were synthesized via the condensation of phosphorochloridic acid diethyl ester with an appropriate pyridinylmethanol in the presence of triethylamine. The compounds have been identified and characterized by IR, far-IR, 1H NMR, 31P NMR, 31P CP-MAS NMR and elemental analyses. The crystal and molecular structures of palladium (II) complexes, i.e., [PdCl2(2-pmOpe)2] and [PdCl2(4-pmOpe)2] determined by the X-ray diffraction method, are presented. In both structures, Pd(II) ions are four-coordinated by two chlorine atoms and two pyridine nitrogen atoms. The geometry of complexes is square-planar and adopt a trans configuration, which is consistent with preparation method.

Graphical abstractThe ligands diethyl (pyridyl-2-, -3-, -4-methyl)phosphate (2-pmOpe, 3-pmOpe, 4-pmOpe) react with K2PdCl4 to produce the palladium(II) complexes of general formula [PdCl2L2] (L = 2-pmOpe, 3-pmOpe, 4-pmOpe) of square-planar geometry and a trans configuration in 80–87% yields.Figure optionsDownload full-size imageDownload as PowerPoint slide