((BuO)-O-t)(3)Mo N and W-2(OBut)(6)(M M) react in hydrocarbons to form Mo-2(OBut)(6)(M M) and ((BuO)-O-t)(3)W N via the reactive intermediate MoW(OBut)(6)(M M). ((BuO)-O-t)(3)W N and CH3C N-15 react in tetrahydrofuran (THF) at room temperature to give an equilibrium mixture involving ((BuO)-O-t)(3)W N-15 and CH3C N. The ((BuO)-O-t)(3)W N compound is similarly shown to act as a catalyst for N-15-atom scrambling between MeC13 N-15 and PhC N to give a mixture of MeC13 N and PhC N-15. From studies of degenerate scrambling of IN atoms involving ((BuO)-O-t)(3)W N and MeC13 N in THF-d(8) by C-13H-1} NMR spectroscopy, the reaction was found to be first order in acetonitrile and the activation parameters were estimated to be Delta H-not equal = 13.4(7) kcal/mol and Delta S-not equal = -32(2) eu. A similar reaction is observed for ((BuO)-O-t)(3)Mo N and (CH3CN15)-N-not equal upon heating in THF-d(8). The reaction is suppressed in pyridine solutions and not observed for the dimeric [((BuMe2SiO)-Me-t)(3)W N](2). The reaction pathway has been investigated by calculations employing density functional theory on the model compounds (MeO)(3)M N and CH3C N where M = Mo and W. The transition state was found to involve a product of the 2 + 2 cycloaddition of M N and C N, a planar metalladiazacyclobutadiene. This resembles the pathway calculated for alkyne metathesis involving (MeO)(3)W CMe, which modeled the metathesis of ((BuO)-O-t)(3)W CBut. The calculations also predict that the energy of the transition state is notably higher for M = Mo relative to M = W.
((BuO)-O-t)(3)Mo N 和 W-2(OBut)(6)(M M) 在烃类中反应,通过反应中间体 MoW(OBut)(6)(M M) 形成 Mo-2(OBut)(6)(M M) 和 ((BuO)-O-t)(3)W N。((BuO)-O-t)(3)W N 和 CH3C N-15 在
四氢呋喃 (THF) 中于室温下反应,生成 ((BuO)-O-t)(3)W N-15 和 CH3C N 的平衡混合物。((BuO)-O-t)(3)W N 化合物还表现出催化 N-15 原子在 MeC13 N-15 和 PhC N 间重排的能力,生成 MeC13 N 和 PhC N-15 的混合物。通过 C-13H-1} 核磁共振光谱对涉及 ((BuO)-O-t)(3)W N 和 MeC13 N 在 THF-d(8) 中的 IN 原子退化重排研究发现,反应对
丙腈呈一级反应,活化参数估计为 ΔH≠ = 13.4(7) kcal/mol 和 ΔS≠ = -32(2) eu。类似地,((BuO)-O-t)(3)Mo N 和 (CH3CN15)-N≠ 在 THF-d(8) 中加热时也观察到类似反应。该反应在
吡啶溶液中受到抑制,且未在二聚体 [((BuMe2SiO)-Me-t)(3)W N]₂ 中观察到。通过密度泛函理论对模型化合物 (MeO)(3)M N 和 CH3C N(M = Mo 和 W)进行计算,研究了反应路径。发现过渡态涉及 M N 和 C N 的 2 + 2 环加成产物,即平面
金属杂
环丁二烯。此路径与对含 (MeO)(3)W CMe 的
炔烃复分解反应的计算结果相似,其中 (MeO)(3)W CMe 模拟了 ((BuO)-O-t)(3)W CBut 的复分解反应。计算还预测,M = Mo 时的过渡态能量显著高于 M = W 时的能量。