Carbon−Phosphorus Bond Activation of Tri(2-thienyl)phosphine at Dirhenium and Dimanganese Centers

Reaction of [Re2(CO)9(NCMe)] with tri(2-thienyl)phosphine (PTh3) in refluxing cyclohexane affords three substituted dirhenium complexes: [Re2(CO)9(PTh3)] (1), [Re2(CO)8(NCMe)(PTh3)] (2), and [Re2(CO)8(PTh3)2] (3). Complex 2 was also obtained from the room-temperature reaction of [Re2(CO)8(NCMe)2] with PTh3 and is an unusual example in which the acetonitrile and phosphine ligands are coordinated to the same rhenium atom. Thermolysis of 1 and 3 in refluxing xylene affords [Re2(CO)8(μ-PTh2)(μ-η1:κ1-C4H3S)] (4) and [Re2(CO)7(PTh3)(μ-PTh2)(μ-H)] (5), respectively, both resulting from carbon−phosphorus bond cleavage of a coordinated PTh3 ligand. Reaction of [Re2(CO)10] and PTh3 in refluxing xylene gives a complex mixture of products. These products include 3−5, two further binuclear products, [Re2(CO)7(PTh3)(μ-PTh2)(μ-η1:κ1-C4H3S)] (6) and [Re2(CO)7(μ-κ1:κ2-Th2PC4H2SPTh)(μ-η1:κ1-C4H3S)] (7), and the mononuclear hydrides [ReH(CO)4(PTh3)] (8) and trans-[ReH(CO)3(PTh3)2] (9). Binuclear 6 is structurally similar to 4 and can be obtained from reaction of the latter with 1 equiv of PTh3. Formation of 7 involves a series of rearrangements resulting in the formation of a unique new diphosphine ligand, Th2PC4H2SPTh. Reaction of [Mn2(CO)10] with PTh3 in refluxing toluene affords the phosphine-substituted product [Mn2(CO)9(PTh3)] (10) and two carbon−phosphorus bond cleavage products, [Mn2(CO)6(μ-PTh2)(μ-η1:η5-C4H3S)] (11) and [Mn2(CO)5(PTh3)(μ-PTh2)(μ-η1:η5-C4H3S)] (12). Both 11 and 12 contain a bridging thienyl ligand that is bonded to one manganese atom in a η5-fashion. The molecular structures of eight of these new complexes were established by single-crystal X-ray diffraction studies, allowing a detailed analysis of the disposition of the coordinated ligands.

将[Re₂(CO)₉(NCMe)]与三(2-噻吩基)膦（tri(2-thienyl)phosphine, PTh3）在回流环己烷（cyclohexane）中反应，可得到三种取代型二铼配合物（dirhenium complexes）：[Re₂(CO)₉(PTh3)]（1）、[Re₂(CO)₈(NCMe)(PTh3)]（2）与[Re₂(CO)₈(PTh3)₂]（3）。配合物2亦可通过[Re₂(CO)₈(NCMe)₂]与PTh3在室温下的反应制得，其为一类少见的实例：乙腈（acetonitrile）与膦配体（phosphine ligands）配位至同一个铼原子上。对配合物1与3在回流二甲苯（xylene）中进行热解（thermolysis），分别得到[Re₂(CO)₈(μ-PTh2)(μ-η¹:κ¹-C₄H₃S)]（4）与[Re₂(CO)₇(PTh3)(μ-PTh2)(μ-H)]（5），二者均由配位态PTh3配体发生碳-磷键断裂（carbon−phosphorus bond cleavage）生成。[Re₂(CO)₁₀]与PTh3在回流二甲苯中反应，得到复杂的产物混合物，其中包含3~5、另外两种双核产物（binuclear products）[Re₂(CO)₇(PTh3)(μ-PTh2)(μ-η¹:κ¹-C₄H₃S)]（6）与[Re₂(CO)₇(μ-κ¹:κ²-Th₂PC₄H₂SPTh)(μ-η¹:κ¹-C₄H₃S)]（7），以及单核氢化物（mononuclear hydrides）[ReH(CO)₄(PTh3)]（8）与反式-[ReH(CO)₃(PTh3)₂]（9）。双核配合物6的结构与4相似，可由后者与1当量PTh3反应得到。配合物7的生成涉及一系列重排过程，最终形成一种独特的新型二膦配体Th₂PC₄H₂SPTh。[Mn₂(CO)₁₀]与PTh3在回流甲苯（toluene）中反应，得到膦取代产物[Mn₂(CO)₉(PTh3)]（10）以及两种碳-磷键断裂产物[Mn₂(CO)₆(μ-PTh2)(μ-η¹:η⁵-C₄H₃S)]（11）和[Mn₂(CO)₅(PTh3)(μ-PTh2)(μ-η¹:η⁵-C₄H₃S)]（12）。11与12均含有桥联噻吩配体，该配体以η⁵配位模式与一个锰原子相结合。通过单晶X射线衍射（single-crystal X-ray diffraction）研究确定了其中8种新型配合物的分子结构，从而可对配位配体的排布方式开展详细分析。