Uddin Md Nazim, Begum Noorjahan, Hassan Mohammad R, Hogarth Graeme, Kabir Shariff E, Miah Md Arzu, Nordlander Ebbe, Tocher Derek A
Department of Chemistry, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh.
Dalton Trans. 2008 Nov 28(44):6219-30. doi: 10.1039/b806846a. Epub 2008 Sep 30.
The synthesis and reactivity of the thiophyne and furyne clusters [Ru3(CO)7(mu-dppm)(mu3-eta2-C4H2E)(mu-P(C4H3E)2)(mu-H)] (E = S, O) is reported. Addition of P(C4H3E)3 to [Ru3(CO)10(mu-dppm)] (1) at room temperature in the presence of Me3NO gives simple substitution products [Ru3(CO)9(mu-dppm)(P(C4H3E)3)] (E = S, 2; E = O, 3). Mild thermolysis in the presence of further Me3NO affords the thiophyne and furyne complexes [Ru3(CO)7(mu-dppm)(mu3-eta2-C4H2E)(mu-P(C4H3E)2)(mu-H)] (E = S, 4; E = O, 6) resulting from both carbon-hydrogen and carbon-phosphorus bond activation. In each the C4H2E (E = S, O) ligand donates 4-electrons to the cluster and the rings are tilted with respect to the mu-dppm and the phosphido-bridged open triruthenium unit. Heating 4 at 80 degrees C leads to the formation of the ring-opened cluster [Ru3(CO)5(mu-CO)(mu-dppm)(mu3-eta3-SC4H3)(mu-P(C4H3S)2)] (5) resulting from carbon-sulfur bond scission and carbon-hydrogen bond formation and containing a ring-opened mu3-eta3-1-thia-1,3-butadiene ligand. In contrast, a similar thermolysis of 3 affords the phosphinidene cluster [Ru3(CO)7(mu-dppm)(mu3-eta2-C4H2O)(mu3-P(C4H3O))] (7) resulting from a second phosphorus-carbon bond cleavage and (presumably) elimination of furan. Treatment of 4 and 6 with PPh3 affords the simple phosphine-substituted products [Ru3(CO)6(PPh3)(mu-dppm)(mu3-eta2-C4H2E)(mu-P(C4H3E)2)(mu-H)] (E = S, 8; E = O, 9). Both thiophyne and furyne clusters 4 and 6 readily react with hydrogen bromide to give [Ru3(CO)6Br(mu-Br)(mu-dppm)(mu3-eta2-eta1-C4H2E)(mu-P(C4H3E)2)(mu-H)] (E = S, 10; E = O, 11) containing both terminal and bridging bromides. Here the alkynes bind in a highly unsymmetrical manner with one carbon acting as a bridging alkylidene and the second as a terminally bonded Fisher carbene. As far as we are aware, this binding mode has only previously been noted in ynamine complexes or those with metals in different oxidation states. The crystal structures of seven of these new triruthenium clusters have been carried out, allowing a detailed analysis of the relative orientations of coordinated ligands.
报道了噻吩炔和呋喃炔簇合物[Ru3(CO)7(μ-dppm)(μ3-η2-C4H2E)(μ-P(C4H3E)2)(μ-H)]（E = S，O）的合成及反应活性。在室温下，于Me3NO存在的条件下，向[Ru3(CO)10(μ-dppm)]（1）中加入P(C4H3E)3，得到简单的取代产物[Ru3(CO)9(μ-dppm)(P(C4H3E)3)]（E = S，2；E = O，3）。在进一步的Me3NO存在下进行温和热解，可得到噻吩炔和呋喃炔配合物[Ru3(CO)7(μ-dppm)(μ3-η2-C4H2E)(μ-P(C4H3E)2)(μ-H)]（E = S，4；E = O，6），这是由碳-氢键和碳-磷键活化产生的。在每种配合物中，C4H2E（E = S，O）配体向簇合物提供4个电子，且环相对于μ-dppm和磷桥联的开放三钌单元发生倾斜。在80℃加热4会导致形成开环簇合物[Ru3(CO)5(μ-CO)(μ-dppm)(μ3-η3-SC4H3)(μ-P(C4H3S)2)]（5），这是由碳-硫键断裂和碳-氢键形成产生的，且含有一个开环的μ3-η3-1-硫杂-1,3-丁二烯配体。相比之下，3的类似热解得到磷烯簇合物[Ru3(CO)7(μ-dppm)(μ3-η2-C4H2O)(μ3-P(C4H3O))]（7），这是由第二次磷-碳键断裂（可能）并消除呋喃产生的。用PPh3处理4和6可得到简单的膦取代产物[Ru3(CO)6(PPh3)(μ-dppm)(μ3-η2-C4H2E)(μ-P(C4H3E)2)(μ-H)]（E = S，8；E = O，9）。噻吩炔和呋喃炔簇合物4和6都能与溴化氢迅速反应，生成含有端基和桥联溴化物的[Ru3(CO)6Br(μ-Br)(μ-dppm)(μ3-η2-η1-C4H2E)(μ-P(C4H3E)2)(μ-H)]（E = S，10；E = O，11）。在此，炔烃以高度不对称的方式结合，一个碳作为桥联亚烷基，另一个作为端基键合的费舍尔卡宾。据我们所知，这种结合模式此前仅在烯胺配合物或具有不同氧化态金属的配合物中被注意到。已对这些新的三钌簇合物中的七种进行了晶体结构测定，从而能够对配位配体的相对取向进行详细分析。
