TY - JOUR
T1 - Dimethylsulfoxide as a Ligand for RhI and IrI Complexes - Isolation, Structure, and Reactivity Towards X-H Bonds (X = H, OH, OCH3)
AU - Dorta, Reto
AU - Rozenberg, Haim
AU - Shimon, Linda J.W.
AU - Milstein, David
PY - 2003/11/7
Y1 - 2003/11/7
N2 - Novel neutral and cationic RhI and IrI complexes that contain only DMSO molecules as dative ligands with S-, O-, and bridging S,O-binding modes were isolated and characterized. The neutral derivatives [RhCl(DMSO)3] (1) and [IrCl(DMSO)3] (2) were synthesized from the dimeric precursors [M2Cl2(coe)4] (M = Rh, Ir; COE = cyclooctene). The dimeric IrI compound [Ir 2Cl2(DMSO)4] (3) was obtained from 2. The first example of a square-planar complex with a bidentate S,O-bridging DMSO ligand, [(coe)(DMSO)Rh-(μ-Cl)(μ-DMSO)RhCl(DMSO)] (4), was obtained by treating [Rh2Cl2(coe)4] with three equivalents of DMSO. The mixed DMSO-olefin complex [IrCl(cod)(DMSO)] (5, COD = cyclooctadiene) was generated from [Ir2Cl2(cod) 2]. Substitution reactions of these neutral systems afforded the complexes [RhCl(py)(DMSO)2] (6), [IrCl(py)(DMSO)2] (7), [IrCl(iPr3P)(DMSO)2] (8), [RhCl(dmbpy)(DMSO)] (9, dmbpy = 4,4′-dimethyl-2,2′-bipyridine), and [IrCl(dmbpy)(DMSO)] (10). The cationic O-bound complex [Rh(cod)(DMSO)2]BF4 (11) was synthesized from [Rh(cod)2]BF4. Treatment of the cationic complexes [M(coe)2(O=CMe2)2]PF6 (M = Rh, Ir) with DMSO gave the mixed S- and O-bound DMSO complexes [M(DMSO) 2(DMSO)2]PF6 (Rh = 12; Ir=in situ characterization). Substitution of the O-bound DMSO ligands with dmbpy or pyridine resulted in the isolation of [Rh(dmbpy)DMSO2]PF6 (13) and [Ir(py)2(DMSO)2]PF6 (14). Oxidative addition of hydrogen to [IrCl(DMSO)3] (2) gave the kinetic product fac-[Ir(H)2Cl(DMSO)3] (15) which was then easily converted to the more thermodynamically stable product mer-[Ir(H) 2Cl(DMSO)3] (16). Oxidative addition of water to both neutral and cationic IrI DMSO complexes gave the corresponding hydrido-hydroxo addition products syn-[(DMSO)2HIr(μ-OH) 2(μ-Cl)IrH(DMSO)2] [IrCl2(DMSO) 2] (17) and anti-[(DMSO)2(DMSO)HIr(μ-OH) 2IrH(DMSO)2(DMSO)][PF6]2 (18). The cationic [Ir(DMSO)2(DMSO)2(DMSO)2]PF 6 complex (formed in situ from [Ir(coe)2(O=CMe 2)2]PF6) also reacts with methanol to give the hydrido-alkoxo complex syn-[(DMSO)2HIr(μ-OCH3) 3IrH(DMSO)2]2]PF6 (19). Complexes 1, 2, 4, 5, 11, 12, 14, 17, 18, and 19 were characterized by crystallography.
AB - Novel neutral and cationic RhI and IrI complexes that contain only DMSO molecules as dative ligands with S-, O-, and bridging S,O-binding modes were isolated and characterized. The neutral derivatives [RhCl(DMSO)3] (1) and [IrCl(DMSO)3] (2) were synthesized from the dimeric precursors [M2Cl2(coe)4] (M = Rh, Ir; COE = cyclooctene). The dimeric IrI compound [Ir 2Cl2(DMSO)4] (3) was obtained from 2. The first example of a square-planar complex with a bidentate S,O-bridging DMSO ligand, [(coe)(DMSO)Rh-(μ-Cl)(μ-DMSO)RhCl(DMSO)] (4), was obtained by treating [Rh2Cl2(coe)4] with three equivalents of DMSO. The mixed DMSO-olefin complex [IrCl(cod)(DMSO)] (5, COD = cyclooctadiene) was generated from [Ir2Cl2(cod) 2]. Substitution reactions of these neutral systems afforded the complexes [RhCl(py)(DMSO)2] (6), [IrCl(py)(DMSO)2] (7), [IrCl(iPr3P)(DMSO)2] (8), [RhCl(dmbpy)(DMSO)] (9, dmbpy = 4,4′-dimethyl-2,2′-bipyridine), and [IrCl(dmbpy)(DMSO)] (10). The cationic O-bound complex [Rh(cod)(DMSO)2]BF4 (11) was synthesized from [Rh(cod)2]BF4. Treatment of the cationic complexes [M(coe)2(O=CMe2)2]PF6 (M = Rh, Ir) with DMSO gave the mixed S- and O-bound DMSO complexes [M(DMSO) 2(DMSO)2]PF6 (Rh = 12; Ir=in situ characterization). Substitution of the O-bound DMSO ligands with dmbpy or pyridine resulted in the isolation of [Rh(dmbpy)DMSO2]PF6 (13) and [Ir(py)2(DMSO)2]PF6 (14). Oxidative addition of hydrogen to [IrCl(DMSO)3] (2) gave the kinetic product fac-[Ir(H)2Cl(DMSO)3] (15) which was then easily converted to the more thermodynamically stable product mer-[Ir(H) 2Cl(DMSO)3] (16). Oxidative addition of water to both neutral and cationic IrI DMSO complexes gave the corresponding hydrido-hydroxo addition products syn-[(DMSO)2HIr(μ-OH) 2(μ-Cl)IrH(DMSO)2] [IrCl2(DMSO) 2] (17) and anti-[(DMSO)2(DMSO)HIr(μ-OH) 2IrH(DMSO)2(DMSO)][PF6]2 (18). The cationic [Ir(DMSO)2(DMSO)2(DMSO)2]PF 6 complex (formed in situ from [Ir(coe)2(O=CMe 2)2]PF6) also reacts with methanol to give the hydrido-alkoxo complex syn-[(DMSO)2HIr(μ-OCH3) 3IrH(DMSO)2]2]PF6 (19). Complexes 1, 2, 4, 5, 11, 12, 14, 17, 18, and 19 were characterized by crystallography.
KW - Iridium
KW - O ligands
KW - Oxidative addition
KW - Rhodium
KW - S ligands
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U2 - 10.1002/chem.200305144
DO - 10.1002/chem.200305144
M3 - Article
C2 - 14613132
AN - SCOPUS:0344065573
VL - 9
SP - 5237
EP - 5249
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 21
ER -