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

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 [LMCl 2 ] 2 (LM = η 6 ‐C 6 Me 6 Ru, η 5 ‐C 5 Me 5 Ir) of ruthenium(II) and iridium(III) only occurs in presence of nucleophiles such as EtOH or H 2 O leading to their metal‐coordination after cleavage of the dimers. [( η 6 ‐C 6 Me 6 )RuCl 2 ] 2 reacts with PDAP and EtOH in the molar ratio 0.5:1:1 to give the phosphorus‐coordinated complex ( η 6 ‐C 6 Me 6 )RuCl 2 ( P ‐PDAP · EtOH) ( 1 ). In the case of [( η 5 ‐C 5 Me 5 )IrCl 2 ] 2 , the triazaphosphole PTAP was used in the presence of EtOH or H 2 O yielding the analogous products ( η 5 ‐C 5 Me 5 )IrCl 2 ( P ‐PTAP · EtOH) ( 2 ) or ( η 5 ‐C 5 Me 5 )IrCl 2 ( P ‐PTAP · H 2 O) ( 3 ). In 1 – 3, the former aromatic azaphosphole ( σ 2 , λ 3 ‐P) has been converted by 1,2 addition of EtOH or H 2 O to their P=C or P=N double bond with the nucleophiles EtO – and OH – bonded to phosphorus ( σ 3 , λ 3 ‐P). Complexes 1 – 3 with a piano‐stool configuration were characterized by elemental analysis, 31 P NMR spectroscopy and single‐crystal X‐ray diffraction.