TY - JOUR
T1 - Pentadienyl-Metal-Phosphine Chemistry. 5.1 The Reaction Chemistry of (η5-2,4-Dimethylpentadienyl)Co[P(C2H5)3]2
AU - Bleeke, John R.
AU - Peng, Wei Jun
PY - 1986
Y1 - 1986
N2 - (η5-2,4-Dimethylpentadienyl)Co[P(C2H5)3]2(1) reacts with small phosphine and phosphite ligands, L, to produce (η3-2,4-dimethylpentadienyl)CoL3(2, L = P(CH3)3, and 3, L = P(OCH3)3) and with bulky ligands to produce (η5-2,4-dimethylpentadienyl)CoL2(4, L = P(n-C3H7)3). 1 is readily oxidized to (η5-2,4-dimethylpentadienyl)Co[P(C2H5)3]2+by Ag+ and acids. The crystal structure of (η5-2,4-dimethylpentadienyl)Co[P(C2H5)3]2+BF4_(5) has been determined by X-ray diffraction. The complex crystallizes in the triclinic space group P1 with a = 9.284 (2) A, b = 10.076 (4) A, c = 8.328 (3) A, α = 114.31 (2)°, β = 116.21 (2)°, y = 91.84 (2)°, and Z = 1. The structure of 5 is similar to that of the neutral parent compound 1 in that the two P(C2H5)3 ligands are oriented with one eclipsing the open edge and one approximately eclipsing the central carbon atom C3 of the pentadienyl ligand. However, in 5 a very pronounced allyl-ene distortion of the pentadienyl ligand is observed. 1 reacts with AgI and with CH3I to produce (η5-2,4-dimethylpentadienyl)Co[P(C2H5)3l(I) (7). This complex crystallizes in the Monoclinic space group Cm with a = 8.142 (1) A,b = 12.416 (4) A, c = 8.479 (2) A, β = 105.23 (1)°, and Z = 2. The molecule resides on a crystallographically imposed mirror plane, which passes through Co, I, P, and the central pentadienyl carbon atom C3. The large P(C2H5)3 ligand sits under the open edge of the pentadienyl ligand, while the smaller iodo ligand resides under pentadienyl carbon atom C3. The reaction of (η5-2,4-dimethylpentadienyl)Co[P(C2H5)3]2+A-(5, A-= BF4-, and 6, A-= O3SCF3-) with 3 equiv of P(CH3)3 produces (η3-2,4-dimethylpentadienyl)Co[P(CH3)3]3+A-(8, A-= BF4-, and 9, A-= O3SCF3-). Both 8 and 9 crystallize in the Monoclinic space group P21/c, The unit cell parameters for 8 are a = 10.565 (2) A, b = 13.207 (3) A, c = 17.595 (4) A, β = 97.77 (2)°, and Z = 4, while those for 9 are a = 10.694 (2) A, b = 14.638 (3) A, c = 17.171 (3) A, β = 96.52 (1)°, and Z = 4. In both 8 and 9, the η3-2,4-dimethylpentadienyl ligand has a W-shaped syn geometry. In contrast, the 2,4-dimethylpentadienyl ligand in the neutral parent compound (η3-2,4-dimethylpentadienyl)Co[P(CH3)3]3(2) adopts a U-shaped anti geometry in the solid state. The 17e Co(II) complexes 5, 7, and 8 react cleanly with P(OCH3)3 to produce 2,4-dimethylpentadiene and diamagnetic five-coordinate Co(I) complexes Co[P(C2H5)3][P(OCH3)3]4+BF4-(10), Co[P(OCH3)3]5+I-(11), and Co[P(CH3)3]2[P(OCH3)3]3+BF4- (12), respectively.
AB - (η5-2,4-Dimethylpentadienyl)Co[P(C2H5)3]2(1) reacts with small phosphine and phosphite ligands, L, to produce (η3-2,4-dimethylpentadienyl)CoL3(2, L = P(CH3)3, and 3, L = P(OCH3)3) and with bulky ligands to produce (η5-2,4-dimethylpentadienyl)CoL2(4, L = P(n-C3H7)3). 1 is readily oxidized to (η5-2,4-dimethylpentadienyl)Co[P(C2H5)3]2+by Ag+ and acids. The crystal structure of (η5-2,4-dimethylpentadienyl)Co[P(C2H5)3]2+BF4_(5) has been determined by X-ray diffraction. The complex crystallizes in the triclinic space group P1 with a = 9.284 (2) A, b = 10.076 (4) A, c = 8.328 (3) A, α = 114.31 (2)°, β = 116.21 (2)°, y = 91.84 (2)°, and Z = 1. The structure of 5 is similar to that of the neutral parent compound 1 in that the two P(C2H5)3 ligands are oriented with one eclipsing the open edge and one approximately eclipsing the central carbon atom C3 of the pentadienyl ligand. However, in 5 a very pronounced allyl-ene distortion of the pentadienyl ligand is observed. 1 reacts with AgI and with CH3I to produce (η5-2,4-dimethylpentadienyl)Co[P(C2H5)3l(I) (7). This complex crystallizes in the Monoclinic space group Cm with a = 8.142 (1) A,b = 12.416 (4) A, c = 8.479 (2) A, β = 105.23 (1)°, and Z = 2. The molecule resides on a crystallographically imposed mirror plane, which passes through Co, I, P, and the central pentadienyl carbon atom C3. The large P(C2H5)3 ligand sits under the open edge of the pentadienyl ligand, while the smaller iodo ligand resides under pentadienyl carbon atom C3. The reaction of (η5-2,4-dimethylpentadienyl)Co[P(C2H5)3]2+A-(5, A-= BF4-, and 6, A-= O3SCF3-) with 3 equiv of P(CH3)3 produces (η3-2,4-dimethylpentadienyl)Co[P(CH3)3]3+A-(8, A-= BF4-, and 9, A-= O3SCF3-). Both 8 and 9 crystallize in the Monoclinic space group P21/c, The unit cell parameters for 8 are a = 10.565 (2) A, b = 13.207 (3) A, c = 17.595 (4) A, β = 97.77 (2)°, and Z = 4, while those for 9 are a = 10.694 (2) A, b = 14.638 (3) A, c = 17.171 (3) A, β = 96.52 (1)°, and Z = 4. In both 8 and 9, the η3-2,4-dimethylpentadienyl ligand has a W-shaped syn geometry. In contrast, the 2,4-dimethylpentadienyl ligand in the neutral parent compound (η3-2,4-dimethylpentadienyl)Co[P(CH3)3]3(2) adopts a U-shaped anti geometry in the solid state. The 17e Co(II) complexes 5, 7, and 8 react cleanly with P(OCH3)3 to produce 2,4-dimethylpentadiene and diamagnetic five-coordinate Co(I) complexes Co[P(C2H5)3][P(OCH3)3]4+BF4-(10), Co[P(OCH3)3]5+I-(11), and Co[P(CH3)3]2[P(OCH3)3]3+BF4- (12), respectively.
UR - https://www.scopus.com/pages/publications/9144250718
U2 - 10.1021/om00135a004
DO - 10.1021/om00135a004
M3 - Article
AN - SCOPUS:9144250718
SN - 0276-7333
VL - 5
SP - 635
EP - 644
JO - Organometallics
JF - Organometallics
IS - 4
ER -