Di‐ and Triazaphospholes as Ligands for Ruthenium(II) and Iridium(III) Complexes 

Abstract

The reaction of the azaphospholes 5‐methyl‐2‐phenyl‐1,2,3‐diazaphospole (PDAP) and 2‐methyl‐2‐phenyl‐1,2,4,3‐triazaphospole (PTAP) with the dimers [LMCl2]2 (LM = η6‐C6Me6Ru, η5‐C5Me5Ir) of ruthenium(II) and iridium(III) only occurs in presence of nucleophiles such as EtOH or H2O leading to their metal‐coordination after cleavage of the dimers. [(η6‐C6Me6)RuCl2]2 reacts with PDAP and EtOH in the molar ratio 0.5:1:1 to give the phosphorus‐coordinated complex (η6‐C6Me6)RuCl2(P‐PDAP·EtOH) (1). In the case of [(η5‐C5Me5)IrCl2]2, the triazaphosphole PTAP was used in the presence of EtOH or H2O yielding the analogous products (η5‐C5Me5)IrCl2(P‐PTAP·EtOH) (2) or (η5‐C5Me5)IrCl2(P‐PTAP·H2O) (3). In 1–3, the former aromatic azaphosphole (σ2,λ3‐P) has been converted by 1,2 addition of EtOH or H2O to their P=C or P=N double bond with the nucleophiles EtO– and OH– bonded to phosphorus (σ3,λ3‐P). Complexes 1–3 with a piano‐stool configuration were characterized by elemental analysis, 31P NMR spectroscopy and single‐crystal X‐ray diffraction.

Electron‐Rich Aromatic 1,3‐Heterophospholes – Recent Syntheses and Impact of High Electron Density at σ2P on the Reactivity

“…Workup of the triazaphosphole Pt(PEt 3 )Cl 2 complexes 87 – 90 and analogous Pd(PEt 3 )Cl 2 complexes in methanol, however, led to reaction with two equivalents of the alcohol and, through ring‐opening and loss of EtCl, to metallacycles 116. 1,2,3‐Di‐ and 1,2,4,3‐triazaphosphole complexes formed with [Ru(C 6 Me 6 )Cl 2 ] 2 and [Ir(C 5 Me 5 )Cl 2 ] 2 in CH 2 Cl 2 seem to be more sensitive and react with traces of EtOH or moisture by addition at the P=C bond 117…”