CARBONYL DISPLACEMENT-REACTIONS OF (C5ME5)TACL2(CO)2(THF) - STRUCTURES OF (C5ME5)TACL2(CO)2(THF), (C5ME5)TACL2(CO)(DMPE), AND (C5ME5)TACL2(METHYL ACRYLATE)

The synthesis and X-ray crystal structure of (C5Me5)TaCl2(CO)2(THF) (1) have been studied. Complex 1 is prepared from the reduction of (C5Me5)TaCl4 by Al/HgCl2 under CO atmosphere and crystallizes in the orthorhombic space group Pbn21 with α = 9.152 (4) Å, b = 14.480 (7) Å, c = 13.738 (6) Å, V = 1821 (1) Å3, and Z = 4. Least-squares refinement converged at R = 0.039 and Rw = 0.036 based on 1777 reflections with I > 3σ(I). Compound 1 reacts with dmpe to yield the complex (C5Me5)TaCl2(CO)(dmpe) (3) in 80% yield. Compound 3 was characterized by a single-crystal X-ray diffraction analysis: space group P21/n; Z = 4; a = 9.463 (6) Å, b = 15.453 (7) Å, c = 14.713 (10) Å; V = 2121 (2) Å3; R = 0.055 and Rw = 0.053 based on 2425 reflections with I > 3σ(I). When allowed to react with methyl acrylate, compound 1 loses two COs to form (C5Me5)TaCl2(methyl acrylate) (6) in 85% yield. Compound 6 was structurally chracterized: space group Pbca; Z = 8; a = 14.704 (4) Å, b = 15.694 (2) Å, c = 14.289 (4) Å; V = 3298 (1) Å3; R = 0.035 and Rw = 0.032 based on 1412 reflections with I > 3σ(I). © 1990, American Chemical Society. All rights reserved.