Syntheses and Molecular Structure of Some Rh and Ru Complexes with the Chelating Diphenyl (2-Pyridyl)phosphine Ligand Wajda-HermanowiczKatarzyna CiunikZbigniew KochelAndrzej 2006 The rhodium(III) complex <i>mer,cis</i>-[RhCl<sub>3</sub>(PPh<sub>2</sub>py-<i>P,N</i>)(PPh<sub>2</sub>py-<i>P</i>)] (<b>1</b>) (PPh<sub>2</sub>py = diphenyl (2-pyridyl)phosphine) has been prepared from RhCl<sub>3</sub>·3H<sub>2</sub>O and PPh<sub>2</sub>py and converted to the <i>trans,cis</i>-[RhCl<sub>2</sub>(PPh<sub>2</sub>py-<i>P,N</i>)<sub>2</sub>]PF<sub>6</sub> (<b>2</b>) in acetone solution by treatment with Ag<sup>+</sup> and PF<sub>6</sub><sup>-</sup>. Ruthenium(III) and ruthenium(II) compounds with PPh<sub>2</sub>py, <i>mer,cis</i>-[RuCl<sub>3</sub>(PPh<sub>2</sub>py-<i>P,N</i>)(PPh<sub>2</sub>py-<i>P</i>)] (<b>3</b>) and <i>mer-</i>[RuCl(PPh<sub>2</sub>py-<i>P,N</i>)<sub>2</sub>(PPh<sub>2</sub>py-<i>P</i>)]Cl (<b>5</b>) have been obtained from DMSO precursor complexes. In a chloroform solution, complex (<b>5</b>) isomerizes to <i>fac-</i>[RuCl(PPh<sub>2</sub>py-<i>P,N</i>)<sub>2</sub>(PPh<sub>2</sub>py-<i>P</i>)]Cl (<i>fac-</i><b>5</b>). All compounds have been characterized by MS, UV−vis, IR, and <sup>1</sup>H and <sup>31</sup>P{<sup>1</sup>H} NMR spectroscopy, and the Ru(III) compound has been characterized by EPR spectroscopy as well. The crystal structures of <b>1</b>, <b>2</b>, <b>3</b>, and <i>fac-</i><b>5</b> have been determined. In all compounds under investigation, at least one pyridylphosphine acts as a chelate ligand. The <sup>31</sup>P chemical shifts for chelating PPh<sub>2</sub>py-<i>P,N</i> depend on the Ru−P bond lengths.