title: Coulombic inter-ligand repulsion effects on the Pt(II) coordination chemistry of oligocationic, ammonium-functionalized triarylphosphines.
abstract: The Pt(II) coordination chemistry of oligocationic ammoniomethyl- and neutral aminomethyl-substituted triarylphosphines (L) is described. Complexes of the type PtX(2)(L)(2) (X = Cl, I) have been isolated and characterized. For the hexa-meta-ammoniomethyl-substituted ligands [1](6+) and [2](6+), two ligands always occupy a trans-configuration with respect to each other in complexes of the type PtX(2)(L)(2), while for the tri-para-ammoniomethyl-substituted ligand [7](3+), the trans/cis ratio is dependent on the ionic strength of the solution. This behaviour was not observed for the neutral aminomethyl-substituted ligands. In the crystal structure of trans-[PtI(2)(1)(2)]I(12), the geometrical parameters of the phosphine ligand [1](6+) are very similar to those found in the analogous complex of the benchmark ligand PPh(3), i.e. trans-PtI(2)(PPh(3))(2), indicating that no significant increase in the steric congestion is present in the complex. Instead, the coordination chemistry of this class of phosphine ligands is dominated by repulsive Coulombic inter-ligand interactions.
authors.affiliation: Organic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: Dennis J M
authors.initials: DJ
authors.lastname: Snelders
authors.forename: Maxime A
authors.initials: MA
authors.lastname: Siegler
authors.forename: Lars S
authors.initials: LS
authors.lastname: von Chrzanowski
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Spek
authors.forename: Gerard
authors.initials: G
authors.lastname: van Koten
authors.forename: Robertus J M
authors.initials: RJ
authors.lastname: Klein Gebbink
mesh_terms: D002712:Chlorides / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010720:Phosphines / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D002712:Chlorides; D008024:Ligands; D010720:Phosphines; D010984:Platinum; C044646:phosphine