Dibrov Sergey M, Deng Bin, Ellis Donald E, Ibers James A
Department of Chemistry, Northwestern University, Illinois 60208-3113, USA.
Inorg Chem. 2005 May 16;44(10):3441-8. doi: 10.1021/ic0483646.
The reaction of solid [RuClCp(PPh(3))(2)] with TeSe(3)(2-) or Se(n)(2-) in DMF leads to the formation of RuCp(PPh(3))(mu(2)-Se(2)) (1). In the structure of this compound the two bridging Se(2) groups lead to a six-membered Ru(2)Se(4) ring in a chair conformation. Attached to each Ru center is a PPh(3) ligand in an equatorial position and a Cp ring in an axial position. The compound is diamagnetic. The compound Ru(2)Cp(2)(mu(3)-Se(2))(mu(3)-Se) (2) is obtained under similar conditions in the presence of air. This structure comprises a centrosymmetric Ru(4)Se(6) dimer formed from the two bridging Se groups and the two bridging Se(2) groups. Each Ru center is pi-bonded to a Cp ring. The reaction of solid [RuClCp(PPh(3))(2)] with a Te(n)(2-) polytelluride solution in DMF leads to the diamagnetic compound [(RuCp(PPh(3)))(2)(mu(2)-(1,4-eta:3,6-eta)Te(6))] (3). Here the Ru centers are bound to a bridging Te(6) chain at the 1, 4, 3, and 6 positions, leading to a bicyclic Ru(2)Te(6) ring. Each Ru atom is bound to a Cp ring and a PPh(3) group. This dimer possesses a center of symmetry. The structure of 3 is the first example of a bicyclic complex where fusion occurs along a Te-Te bond. If the same reaction is carried out in DMF/CH(2)Cl(2), rather than DMF, then [(RuCp(PPh(3)))(2)(mu(2)-(1,4-eta:3,6-eta)Te(6))].CH(2)Cl(2) (4) is obtained. In the solid state it possesses the same Ru(2)Te(6) structural unit as does 3, but the unit lacks a crystallographically imposed center of symmetry. The electronic structures of 3 and 4 have been analyzed with the use of first principles density functional theory. Bond order analysis indicates that the Te-Te bond where fusion occurs has a shared bonding charge of about (2)/(3) of that found for Te-Te single bonds.
固体[RuClCp(PPh(3))(2)]与TeSe(3)(2-)或Se(n)(2-)在N,N - 二甲基甲酰胺（DMF）中反应生成RuCp(PPh(3))(μ(2)-Se(2))（1）。在该化合物的结构中，两个桥联的Se(2)基团形成了一个椅式构象的六元Ru(2)Se(4)环。每个Ru中心在赤道位置连接一个三苯基膦（PPh(3)）配体，在轴向位置连接一个环戊二烯基（Cp）环。该化合物是抗磁性的。化合物Ru(2)Cp(2)(μ(3)-Se(2))(μ(3)-Se)（2）在类似条件下于空气中得到。该结构由两个桥联的Se基团和两个桥联的Se(2)基团形成一个中心对称的Ru(4)Se(6)二聚体。每个Ru中心通过π键与一个Cp环相连。固体[RuClCp(PPh(3))(2)]与DMF中的碲化物Te(n)(2-)多碲化物溶液反应生成抗磁性化合物[(RuCp(PPh(3)))(2)(μ(2)-(1,4 - η:3,6 - η)Te(6))]（3）。在这里，Ru中心在1、4、3和6位与一个桥联的Te(6)链相连，形成一个双环Ru(2)Te(6)环。每个Ru原子与一个Cp环和一个PPh(3)基团相连。该二聚体具有对称中心。3的结构是第一个沿Te - Te键发生稠合的双环配合物的例子。如果在DMF/二氯甲烷（CH(2)Cl(2)）中而不是在DMF中进行相同反应，则得到[(RuCp(PPh(3)))(2)(μ(2)-(1,4 - η:3,6 - η)Te(6))].CH(2)Cl(2)（4）。在固态中，它具有与3相同的Ru(2)Te(6)结构单元，但该单元缺乏晶体学上强制的对称中心。已使用第一性原理密度泛函理论对3和4的电子结构进行了分析。键级分析表明，发生稠合的Te - Te键的共享键电荷约为Te - Te单键的(2)/(3)。
