Crystal and molecular structures of decamethylmanganocene and decamethylferrocene. Static Jahn-Teller distortion in a metallocene
Crystal and molecular structures of decamethylmanganocene and decamethylferrocene. Static Jahn-Teller distortion in a metallocene
复制标题
十甲基二茂锰和十甲基二茂铁的晶体和分子结构。
DOI：
10.1021/ja00498a017
复制
发表时间：
1979
影响因子：
15
通讯作者：
J. C. Smart
中科院分区：
文献类型：
--
作者：
D. Freyberg;J. Robbins;K. Raymond;J. C. Smart
用单晶X-射线衍射法测定了双(五甲基环戊二烯)锰(11)和铁(11)的晶体和分子结构。这两种化合物的晶体堆积紧密相关且高度有序，可以对结构参数进行详细比较。这两种茂金属都含有平面交错的MejCp环。铁烯对应于DS‘t的分子对称性，平均Fe-C和CC距离分别为2.050(2)和1.419(2)×。低自旋新锰系在D对称性下具有轨道简并的2E2g基态。在固体状态下，这种简并可以通过(1)CC环距离从1.409(2)到1.434(2)α的CP环的扭曲和(2)茂金属“三明治”的上半部分和下半部分的小滑动而得到缓解，从而得到从2.105(2)到2.118(2)α的范围内的Mn-C键长度。在这两种结构中，甲基都偏离了Cp环上的0.06°金属原子。(CstCf，EEMn)的OR-Ange晶体符合C2/c空间群，a=15.143(4)，b=12.248(3)，c=9.910(3)，？=93.56(3)。对于F02和Gt；3a(F02)的2581个独立反射，R=3.6%，RW=5.0%。(C_5(CH_3)_5)_2Fe的橙色晶体符合CMCA空间群，a=15.210(3)，b=11.887(2)，c=9.968(2)？对于F02和Gt；2n(F02)的1217个独立反射，R=3.9%，RW=5.5%。这两种结构每个晶胞都有四个分子，分别具有C、(Mn)和ClH(Fe)晶位对称性。
The crystal and molecular structures of bis (pentamethylcyclopentadienyl) manganese (ll) and-lron (ll) have been determined by single-crystal X-ray diffraction. The crystal packing of the two compounds is closely related and highly ordered, allowing a detailed comparison of structural parameters. Both metallocenes contain planar, staggered MejCp rings. The ferro-cene corresponds to a molecular symmetry of Ds¡ t with average Fe-C and CC distances of 2.050 (2) and 1.419 (2) Á, respec-tively. The low-spin manganocene has an orbitally degenerate 2E2g ground state in Dsymmetry. This degeneracy is relieved in the solid state by (1) a distortion of the Cp rings in which CC ring distances range from 1.409 (2) to 1.434 (2) Á and (2) a small slippage of the top and bottom halves of the metallocene “sandwich” to give Mn-C bond lengths which range from 2.105 (2) to 2.118 (2) Á. In both structures themethyl groups bend away from the metal atom 0.06 Á from the Cp rings. Or-ange crystals of (CstCF^ EEMn conform to the space group C2/c with a= 15.143 (4) Á, b= 12.248 (3) Á, c= 9.910 (3) Á, and ß= 93.56 (3). For 2581 independent reflections with F02> 3a (F02), R= 3.6%, Rw= 5.0%. Orangecrystals of (C5 (CH3) 5) 2Fe conform to the space group Cmca with a= 15.210 (3), b= 11.887 (2), and c= 9.968 (2) Á. For 1217 independent reflections with F02> 2n (F02), R= 3.9% and Rw= 5.5%. Both structures have four molecules per unit cell with C,(Mn) and Cih (Fe) crystallographic site symmetry, respectively.