TY - JOUR
T1 - Synthesis and Complexation of a New Chelating Bis(phosphite) Ligand, pinacop. Structural Characterization of (2, 4-Dimethylpentadienyl)M(pinacop) Complexes (M = Co, Rh)
AU - Bleeke, John R.
AU - Donaldson, Andrew J.
AU - Peng, Wei Jun
PY - 1988/1/1
Y1 - 1988/1/1
N2 - A new chelating bis (phosphite) ligand, OCMe2CMe2OPOCMe2CMe2OPOCMe2CMe2O or “pinacop”, has been synthesized via condensation of pinacol with phosphorus trichloride. The addition of pinacop to the low-temperature reaction product of CoCl2 and 2 equiv of potassium 2, 4-dimethylpentadienide yields (2, 4-dimethylpentadienyl)Co(pinacop) (1), which has been structurally characterized. 1 crystallizes in the monoclinic space group Cc with a = 13.964 (7) Å, b = 16.018 (5) Å, c = 13.775 (3) Å, β= 108.58 (3)°, V = 2921 (2) Å3, and Z = 4. The pinacop ligand is oriented with one phosphorus atom eclipsing the open edge and the other phosphorus atom eclipsing the central carbon, C3, of the U-shaped η5-dimethylpentadienyl group. (2, 4-Dimethylpentadienyl)Rh(pinacop) (2) has been synthesized by reacting [(pinacop)RhCl]2 with 2 equiv of potassium 2, 4-dimethylpentadienide and has been structurally characterized. 2 crystallizes in the monoclinic space group P21/n with a = 10.609 (3) Å, b = 25.241 (6) Å, c = 11.500 (1) Å, β = 104.36 (2)°, V = 2983 (1) Å3, and Z = 4. The dimethylpentadienyl ligand in 2 is bonded to the Rh center in an η3fashion and adopts an anti-rotated (sickle shaped) geometry. The overall coordination geometry for 16 e− 2 is square planar with Cl and C3 of the dimethylpentadienyl ligand and PI and P2 of the pinacop ligand occupying the four coordination sites. In solution, 2 exists as an equilibrium mixture of anti-η3-and syn-η3-2, 4-dimethylpentadienyl isomers. The anti isomer undergoes a fluxional process, which exchanges the ends of the dimethylpentadienyl ligand via an 18 e− (η5-2, 4-dimethylpentadienyl)Rh(pinacop) intermediate.
AB - A new chelating bis (phosphite) ligand, OCMe2CMe2OPOCMe2CMe2OPOCMe2CMe2O or “pinacop”, has been synthesized via condensation of pinacol with phosphorus trichloride. The addition of pinacop to the low-temperature reaction product of CoCl2 and 2 equiv of potassium 2, 4-dimethylpentadienide yields (2, 4-dimethylpentadienyl)Co(pinacop) (1), which has been structurally characterized. 1 crystallizes in the monoclinic space group Cc with a = 13.964 (7) Å, b = 16.018 (5) Å, c = 13.775 (3) Å, β= 108.58 (3)°, V = 2921 (2) Å3, and Z = 4. The pinacop ligand is oriented with one phosphorus atom eclipsing the open edge and the other phosphorus atom eclipsing the central carbon, C3, of the U-shaped η5-dimethylpentadienyl group. (2, 4-Dimethylpentadienyl)Rh(pinacop) (2) has been synthesized by reacting [(pinacop)RhCl]2 with 2 equiv of potassium 2, 4-dimethylpentadienide and has been structurally characterized. 2 crystallizes in the monoclinic space group P21/n with a = 10.609 (3) Å, b = 25.241 (6) Å, c = 11.500 (1) Å, β = 104.36 (2)°, V = 2983 (1) Å3, and Z = 4. The dimethylpentadienyl ligand in 2 is bonded to the Rh center in an η3fashion and adopts an anti-rotated (sickle shaped) geometry. The overall coordination geometry for 16 e− 2 is square planar with Cl and C3 of the dimethylpentadienyl ligand and PI and P2 of the pinacop ligand occupying the four coordination sites. In solution, 2 exists as an equilibrium mixture of anti-η3-and syn-η3-2, 4-dimethylpentadienyl isomers. The anti isomer undergoes a fluxional process, which exchanges the ends of the dimethylpentadienyl ligand via an 18 e− (η5-2, 4-dimethylpentadienyl)Rh(pinacop) intermediate.
UR - https://www.scopus.com/pages/publications/0039289440
U2 - 10.1021/om00091a007
DO - 10.1021/om00091a007
M3 - Article
AN - SCOPUS:0039289440
SN - 0276-7333
VL - 7
SP - 33
EP - 37
JO - Organometallics
JF - Organometallics
IS - 1
ER -