Direct Synthesis and Structure of ￥?4-1-Functionally Substituted 2,3,4,5-Tetraphenyl-1-Silacyclopenta-2,4-diene Complexes of Irontricarbonyl

摘要

We obtained the new complexes, Fe[ョ 4-R,R`-TPSCp](CO)3(R,R`-TPSCp = 1,1-disubstituted 2,3,4,5-Tetraphenyl-1-Silacyclopenta-2,4-diene; R = Ph, R` = Cl, R = R` = Cl) from the reaction of the corresponding R,R`-TPSCp with ironpentacarbonyl under reflux in toluene. Also, the analogous complexes with R = R` = Me and R = Me, R` = Cl were obtained in an identical manner. We have determined the crystal structure of Fe[Ph(Cl)-TPSCp](CO)3 by using Mo ka, ル = 0.71069∈, where the unit cell was found to be monoclinic with a = 9.042 (6)∈, b = 19.870 (9)∈, c = 17.426 (9)∈ and モ = 96.28(4)∑. The butadiene moiety of TPSCp ring is planar and the dihedral angle of the butadiene plane and C4-Si-C25 plane was opened up to 41.8∑. The C-C distances in the butadiene moiety were found to be 1.4346, 1.462, and 1.440 ∈, respectively. It may be said that the four ヰ-electrons are delocalized over the four carbons in five membered ring through coordination with ironcarbonyl. In this complex Fe is either in distorted tetrahedron environment with the centroid of the four C-atom butadiene moiety and three carbons of the three carbonyls or in distorted square-pyramidal environment with two midpoints of double bonds of the butadiene moiety and two carbons of carbonyl defining the base of the pyramid and the carbon of remaining carbonyl the apex.