title: Reactions of pyridyl-functionalized, chelating λ3-phosphinines in the coordination environment of Rh(III) and Ir(III).
abstract: Rh(III) and Ir(III) complexes based on the λ(3)-P,N hybrid ligand 2-(2'-pyridyl)-4,6-diphenylphosphinine (1) react selectively at the P=C double bond to chiral coordination compounds of the type [(1H⋅OH)Cp*MCl]Cl (2,3), which can be deprotonated with triethylamine to eliminate HCl. By using different bases, the pKa value of the P-OH group could be estimated. Whereas [(1H⋅O)Cp*IrCl] (4) is formed quantitatively upon treatment with NEt3, the corresponding rhodium compound [(1H⋅O)Cp*RhCl] (5) undergoes tautomerization upon formation of the λ(5)σ(4)-phosphinine rhodium(III) complex [(1⋅OH)Cp*RhCl] (6) as confirmed by single-crystal X-ray diffraction. Blocking the acidic P-OH functionality in 3 by introducing a P-OCH3 substituent leads directly to the λ(5)σ(4)-phosphinine iridium(III) complex (8) upon elimination of HCl. These new transformations in the coordination environment of Rh(III) and Ir(III) provide an easy and general access to new transition-metal complexes containing λ(5)σ(4)-phosphinine ligands.
authors.affiliation: Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands.
authors.forename: Iris
authors.initials: I
authors.lastname: de Krom
authors.forename: Evgeny A
authors.initials: EA
authors.lastname: Pidko
authors.forename: Martin
authors.initials: M
authors.lastname: Lutz
authors.forename: Christian
authors.initials: C
authors.lastname: Müller
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007495:Iridium / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: C556846:2-(2'-pyridyl)-4,6-diphenylphosphinine; D001555:Benzene Derivatives; D002614:Chelating Agents; D056831:Coordination Complexes; D008024:Ligands; D009943:Organophosphorus Compounds; D010720:Phosphines; D011725:Pyridines; C519090:phosphinine; D007495:Iridium; D012238:Rhodium