2-(2'-Pyridyl)-4,6-diphenylphosphinine versus 2-(2'-pyridyl)-4,6-diphenylpyridine: synthesis, characterization, and reactivity of cationic Rh(III) and Ir(III) complexes based on aromatic phosphorus heterocycles.
The bidentate P,N hybrid ligand 1 allows access for the first time to novel cationic phosphinine-based Rh(III) and Ir(III) complexes, broadening significantly the scope of low-coordinate aromatic phosphorus heterocycles for potential applications. The coordination chemistry of 1 towards Rh(III) and Ir(III) was investigated and compared with the analogous 2,2'-bipyridine derivative, 2-(2'-pyridyl)-4,6-diphenylpyridine (2), which showed significant differences. The molecular structures of [RhCl(Cp*)(1)]Cl and [IrCl(Cp*)(1)]Cl (Cp*=pentamethylcyclopentadienyl) were determined by means of X-ray diffraction and confirm the mononuclear nature of the λ(3) -phosphinine-Rh(III) and Ir(III) complexes. In contrast, a different reactivity and coordination behavior was found for the nitrogen analogue 2, especially towards Rh(III) as a bimetallic ion pair [RhCl(Cp*)(2)](+) [RhCl3 (Cp*)](-) is formed rather than a mononuclear coordination compound. [RhCl(Cp*)(1)]Cl and [IrCl(Cp*)(1)]Cl react with water regio- and diastereoselectively at the external PC double bond, leading exclusively to the anti-addition products [MCl(Cp*)(1H⋅OH)]Cl as confirmed by X-ray crystal-structure determination.
Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands.
Iris
I
de Krom
Leen E E
LE
Broeckx
Martin
M
Lutz
Christian
C
Müller
D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D006571:Heterocyclic Compounds / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D010720:Phosphines / Q000138:chemical synthesis* / Q000737:chemistry*; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*
C556846:2-(2'-pyridyl)-4,6-diphenylphosphinine; C582828:2-(2'-pyridyl)-4,6-diphenylpyridine; D002412:Cations; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D010720:Phosphines; D011725:Pyridines; D007495:Iridium; D012238:Rhodium