(η⁵‐Pentamethylcyclopentadienyl)iridium(III) Complexes with η²‐N,O andη²‐P,S Ligands

Abstract

Chloro(η5‐pentamethylcyclopentadienyl)(η2‐pyridine‐2‐car‐boxylato)iridium(III) [Ir(η5‐C5Me5)(η2‐C5H4N‐2‐CO2)Cl] (2) and chloro(η5‐pentamethylcyclopentadienyl)[η2‐2‐(diphenylphosphanyl)thiophenolato]iridium(III) [Ir(η5‐C5Me5)(η2‐2‐Ph2PC6H4S)Cl] (3) were prepared and their structures determined by single‐crystal X‐ray diffraction analysis. Complex 2 crystallizes in the orthorhombic space group Pbca. The number of molecules per unit cell is eight, whereas 3 crystallizes in the orthorhombic space group Pna21 and the number of molecules per unit cell is four. The coordination of the η2‐bound ligands in 2 and 3 leads to chelate bite angles N–Ir–O(2) and P–Ir–S of 77.0(2)° and 82.42(7)°, respectively. The iridium atoms in 2 and 3 are chiral and both enantiomers are present in the unit cell. The substitution of the chloro ligand in 3 affords hydrido(η5‐pentamethylcyclopentadi‐enyl)‐[η2‐2‐(diphenylphosphanyl)thiophenolato]iridium(III][Ir(η5C5Me5)(η2‐2‐Ph2PC6H4S)H] (4) and methyl(η5‐penta‐methylcyclopentadienyl)[η2‐2‐(diphenylphosphanyl)thiophen‐olato]iridium(III) [Ir(η5‐C5Me5)(η2‐2‐Ph2PC6H4S)Me] (5), respectively, in good yields. The 31P{1H} NMR resonances of 4 (δ = 33.9 ppm) and 5 (δ = 35.8 ppm) prove unambiguously that the 2‐(diphenylphosphanyl)thiophenolato ligand still remains η2‐coordinated.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Synthesis and characterization of half-sandwich Rh, Ir complexes containing mono-thiolate-ortho-carborane ligand

“…5. The solid state molecular structure reveals the geometry at the Ir(III) center are analogous to these of (16) Å, are all comparable to those reported for the Ir(III) complexes with P,S-ligands [49,50].…”

Organometallic Half-Sandwich Iridium Anticancer Complexes

“…Significant increases in activity for complexes 7-9, 10-11 and 12-14 are also observed. On the other hand, the chelating ligand can also 33 play an important role in the anticancer activity. For example, the pico complex 13 shows no activity toward the A2780 cell line while the bpy analogue complex 8 shows good activity, and the bpy complex 9 is more than one order of magnitude more potent than the pico analogue, complex 14.…”

Half-sandwich iridium complexes—Synthesis and applications in catalysis

“…The 2-substitued OH group is believed to play a critical role in the hydrogen generation; the analogous 3-and 4-OH complexes were much less active. The iridium dimer has also been used as catalyst for the conversion of alcohols into amines via a process of dehydrogenation of the alcohol, condensation to form an imine, and finally hydrogenation to afford the amine ( Table 9, entries [8][9][10][11][12][13][14][15]. It is noted that this "borrowing hydrogen" strategy has also been applied to the formation of C-C bond from alcohols via alkene and aldehydes derived from dehydrogenation of the alcohols [128][129][130][131][132].…”

“…Thus, reaction of [Cp*IrCl 2 ] 2 with sodium pyridine-2-carboxylate or sodium 2-(diphenylphosphanyl)thiophenolate afforded the corresponding iridium η 2 -(N,O) and η 2 -(S,P) half-sandwich complexes 6 and 7 (Table 1, entries 3, 4) [15]. The structurally similar iridium carboxylato pyrazine complex 8 was prepared from [Cp*IrCl 2 ] 2 and pyrazine-2-carboxylic acid in the presence of sodium methoxide (Table 1, entry 5) [16].…”