铁硫原子簇配合物(μ-MeS)[μ-Fe(CO)2CpS]Fe2(CO)6的晶体和分子结构

标题化合物为单斜晶系, 空间群P2_1/n, 晶胞参数:a=0.79099(7), b=1.0774(1), c=2.2531(4) nm, γ=92.91(1)°, Z=4。本文讨论了铁硫原子簇配合物(μ-R~1S)(μ-R~2S)Fe_2(CO)_6中, 取代基R~1, R~2大小对化合物结构的影响。当R为较大的基团, 如PPh_3或Fe(CO)_2Cp时, 平均Fe-S键增长。而且簇骨架外的Fe-S键增长比簇骨架内的Fe-S键增长更加明显, 说明Fe-Fe键有稳定骨架的作用。R基团的大小对簇骨架内的扭角S-Fe-Fe-S也有明显的影响。标题化合物中R~1, R~2取代基采取(a,e)构象排布, 有利于缓解取代基间的空间排斥作用。

CRYSTAL STRUCTURE OF Fe-S CLUSTER COMPLEX (μ-MeS)[μ-Fe(CO)2CpS]Fe2(CO)6

The influences of the different substituents R~1 and R~2 on the structures of (μ-R~1S)(μ-R~2S)Fe_2(CO)_6 cluster complexes were studied. The -Fe(CO)_2Cp] is a novel substituent, and thus there are some characteristics in the complex. The title complex belongs to monoclinic system, space group P2_1/n. The unit cell parameters a=0.79099(7), b=1.0774(1), c=2.2531(4) nm, γ=92.91(1)°, z=4, and D_=1.856 gcm~(-3). Refinement converged at R=0.024 and R_w=0.030 for the 2110 reflections with I≥3σ(I). The Fe-S(2) bond length are longer than the Fe-S(1) bond lengty, and the S(2) atom is bonded with the larger substituent Fe(CO)_2Cp. The unequivalency of the Fe-S bonds in the S bridges relates to the diffrentia between R~1 and R~2. The average length of Fe-S bonds is increased, when the fe or S atom is bonded with a large substituent, like PPh_3 or Fe(CO)_2Cp. Besides, the torsion angle of the cluster skeleton is sensitive to the existence of the large substituent. The Fe-S bond distancs inside the cluster skeleton ae shorter than that outside the cluster skeleton. It is thus obvious that the Fe-Fe bond has the effect of stabilizing the skeleton. The conformation of the substituents is (a,e) type. This is favourable for decreasing the reelling effect between the substituents.【DOI】 cnki:ISSN:1000-6818.0.1987-06-008