TY - JOUR
T1 - Synthesis and reactivity of [Ir(C2H4) 2TpmMe2]PF6 (TpmMe2 = Tris(3,5-dimethylpyrazolyl)methane)
T2 - Comparison with the analogous Tp Me2 derivatives (TpMe2 = Hydrotris(3,5-dimethylpyrazolyl) borate)
AU - Padilla-Martínez, Itzia I.
AU - Poveda, Manuel L.
AU - Carmona, Ernesto
AU - Monge, M. Angeles
AU - Ruiz-Valero, Caridad
PY - 2002/1
Y1 - 2002/1
N2 - A series of cationic Ir complexes of the neutral TpmMe2 ligand (TpmMe2 = tris(3,5-dimethylpyrazolyl)methane) have been investigated and compared, chemically and structurally, with the analogous derivatives of the monoanionic TpMe2 (TpMe2 = hydrotris(3,5- dimethylpyrazolyl)borate). The bis(ethene) compound [Ir(C2H 4)2TpmMe2]PF6 (1) undergoes olefinic C-H activation under very mild conditions to give first [Ir(H)(CH=CH 2)(C2H4)-TpmMe2]+ (2) (all cationic species described have been isolated in the form of PF 6- salts) and subsequently hydride-crotyl products derived from C-C coupling of the hydrocarbon ligands of 2. A different bond-forming reaction has been encountered during the solid-state thermal activation of 1 (suspended in C6H12), leading to the hydride-α,ω-butenyl derivative 4. X-ray studies on the latter compound show close structural analogies with related complexes of the TpMe2 ligand and, specifically, a striking similarity of the structural parameters of the IrTpmMe2 and IrTpMe2 moieties. Compound 4 reacts with hard donors, giving [Ir(CH2CH2-CH2CH 2)(L)TpmMe2]+ adducts (9; L = py, NCMe), whereas the soft donors PR3 (R = Me, Et) and CN- allow the isolation of complexes derived from the attack of the soft nucleophile at the internal coordinated olefinic carbon (complexes 10a-c). Hydrogenation of 1 under different experimental conditions permits the production of different hydride products, e.g. [Ir(H)2(C2H4)Tpm Me2]+ (13) and [Ir(H)(C2H5)(C 2H,)TpmMe2]+ (12). Carbene derivatives resulting from the regioselective double C-H bond activation of THF (compounds 11 and 16) have been produced using 4 and 13 as the reactants.
AB - A series of cationic Ir complexes of the neutral TpmMe2 ligand (TpmMe2 = tris(3,5-dimethylpyrazolyl)methane) have been investigated and compared, chemically and structurally, with the analogous derivatives of the monoanionic TpMe2 (TpMe2 = hydrotris(3,5- dimethylpyrazolyl)borate). The bis(ethene) compound [Ir(C2H 4)2TpmMe2]PF6 (1) undergoes olefinic C-H activation under very mild conditions to give first [Ir(H)(CH=CH 2)(C2H4)-TpmMe2]+ (2) (all cationic species described have been isolated in the form of PF 6- salts) and subsequently hydride-crotyl products derived from C-C coupling of the hydrocarbon ligands of 2. A different bond-forming reaction has been encountered during the solid-state thermal activation of 1 (suspended in C6H12), leading to the hydride-α,ω-butenyl derivative 4. X-ray studies on the latter compound show close structural analogies with related complexes of the TpMe2 ligand and, specifically, a striking similarity of the structural parameters of the IrTpmMe2 and IrTpMe2 moieties. Compound 4 reacts with hard donors, giving [Ir(CH2CH2-CH2CH 2)(L)TpmMe2]+ adducts (9; L = py, NCMe), whereas the soft donors PR3 (R = Me, Et) and CN- allow the isolation of complexes derived from the attack of the soft nucleophile at the internal coordinated olefinic carbon (complexes 10a-c). Hydrogenation of 1 under different experimental conditions permits the production of different hydride products, e.g. [Ir(H)2(C2H4)Tpm Me2]+ (13) and [Ir(H)(C2H5)(C 2H,)TpmMe2]+ (12). Carbene derivatives resulting from the regioselective double C-H bond activation of THF (compounds 11 and 16) have been produced using 4 and 13 as the reactants.
UR - http://www.scopus.com/inward/record.url?scp=0037570359&partnerID=8YFLogxK
U2 - 10.1021/om010594u
DO - 10.1021/om010594u
M3 - Artículo
SN - 0276-7333
VL - 21
SP - 93
EP - 104
JO - Organometallics
JF - Organometallics
IS - 1
ER -