Pentamethylcyclopentadienyl-rhodium and -iridium complexes. Part 29. Syntheses and X-ray structure determinations of [{Rh(C5Me5)}2(OH)3]OH·11H2O and [{lr(C5Me5)}2(OH)3]O2CMe·14H2O and related complexes
The complexes [{M(C5H5)}2(OH)3]X·nH2O (M = Rh, X = PF6 and OH; M = Ir, X = O2CMe, OH, and BPh4) have been prepared. Single-crystal X-ray structure determinations have been carried out on [{Rh(C5Me5)}2(OH)3]OH·11H2O (2c) and on [{Ir(C5Me5)}2(OH)3]O2CMe·14H2O (3a). Both show two metal atoms each η5-bonded to a C5Me5 ligand and bridged by three hydroxo-ligands with Rh ⋯ Rh 2.973 8(8)Å, Ir ⋯ Ir 3.070 9(7)Å, Rh–O (mean) 2.109 Å, Ir–O (mean) 2.120 Å, Rh–O–Rh (mean) 89.6(1)°, and Ir–O–Ir (mean) 92.8(3)°. Both (2c) and [{lr(C5Me5)}2(OH)3]OH·nH2O are very strong bases in water. Reaction of [{Rh(C5Me5)}2Cl4](1) with Ag2SO4 gave Rh(C5Me5)(SO4)·2H2O which probably exists in water as the dication [Rh(C5Me5)(H2O)3]2+ and which is quantitatively carbonylated (20 °C, 1 atm, 48 h) to [Rh(C5Me5)(CO)2]. The carbonato-complex Rh(C5Me5)(CO3)·2H2O was obtained from (1) and Ag2CO3 or by air-oxidation of [{Rh(C5Me5)}2(CO)2]. Reaction of [{Rh(C5Me5)}2(OH)3]Cl with P(OMe)3 gave the unexpected methylrhodium complex [Rh(C5Me5)Me{P(OMe)3}2]+ as well as [Rh(C5Me5){P(OMe)3}3]2+.