173094-01-4Relevant academic research and scientific papers
Molybdenum and tungsten cyclopentadienone complexes. 1. Synthesis and characterization
Mauthner, Klaus,Slugovc, Christian,Mereiter, Kurt,Schmid, Roland,Kirchner, Karl
, p. 181 - 188 (2008/10/08)
The labile complexes M(CO)3(CH3CN)3 (M = M0, W) undergo facile oxidative addition reactions with 4-bromo-2-cyclopentenone to give M(η3-C5H5O)(CO)2(CH 3CN)2Br 1a and 2. Complex 1a crystallizes in space group P21/m (No. 11) with a = 8.631 (2) A?, b = 12.852 (3) A?, c = 6.659 (2) A?, β = 109.27 (1)°, V = 697.3 (3) A?3, and Z = 2. The structure was refined to R(F) = 0.023 (F ≥ 4σF). 1 and 2 react with potassium tris(pyrazolyl)borate (K[HBpZ3]), 2,2′-bipyridyl (bipy), and bis(diphenylphosphino)methane (dppm) to give neutral η3-cyclopentenoyl complexes of types M(η3-C5H5O)(CO)2(HBpZ 3) 3a and 4, M(η3-C5H5O)(CO)2(bipy)-Br 5 and 6, and M(η3-C5H5O)(CO)2(dppm)Br 7 and 8, respectively, in high yields. Single crystal structural studies have been carried out for complexes 3a, 4, and 8. 3a crystallizes in space group Pbca (No. 61) with a = 19.819 (3) A?, b = 13.899 (3) A?, c = 13.088 (2) A?, V = 3605 (1) A?3, and Z = 8, and the structure was refined to R(F) = 0.026 (F ≥ 4σF). 4 is isostructural with 3a and crystallizes in space group Pbca (No. 61) with a = 19.726 (6) A?, b = 13.924 (6) A?, c = 13.080 (4) A?, V = 3593 (2) A?3, and Z = 8, and the structure was refined to R(F) = 0.028 (F ≥ 4σF). 8 crystallizes in space group P1 (No. 2) with a = 10.143 (3) A?, b = 10.972 (4) A?, c = 13.708 (5) A?, α = 82.52 (2)°, β = 85.07 (2)° , γ= 84.77 (1)°, V = 1502.0 (9) A?3, and Z = 2. The structure was refined to R(F) = 0.029 (F ≥ 4σF). Treatment of complexes 3-8 with Ph3C+PF6- in methylene chloride solution led to facile hydride abstraction and formation of the stable cationic η4-cyclopentadienone complexes [M(η4-C5H4O)(CO)2 (HBpz3)]PF6 9a and 10, [M(η4-C5H4O)(CO) 2(bipy)Br]PF6 11 and 12, and [W(η4-C5H4O)(CO) 2(dppm)Br]PF6 (13). Complex 10 has been found to crystallize in space group Pcab (No. 61) with a = 18.242 (4) A?, b = 17.145 (4) A?, c = 13.188 (3) A, V = 4125 (2) A?3, and Z = 8. The structure was refined to R(F) = 0.029 (F ≥ 4σF). 13 crystallizes in space group P21/n (No. 14) with a = 11.796 (3) A?, b = 17.512 (7) A?, c = 17.210 (5) A?, β= 93.67 (1)°, V = 3548 (2) A?3, and Z = 4. The structure was refined to R(F) = 0.040 (F ≥ 4σF).
