is faster than that of the previously reported PMe3 analogs W(CH2SiMe3)3(≡CSiMe3)(PMe3) (2a) ⇌ W(CH2SiMe3)2(═CHSiMe3)2(PMe3) (2b).(1) The 4a ⇌ 4b mixture undergoes an α-H abstraction, yielding alkyl alkylidene alkylidyne complexes W(CH2SiMe3)(═CHSiMe3)(≡CSiMe3)(DMPE) (syn, 7a; anti, 7b) containing chelating DMPE ligand with the following activation parameters: ΔH2⧧ = 13.2(1.3) kcal/mol and ΔS2⧧ = −36(4)
的反应W(CH 2森达3)3(≡CSiMe 3)(1)配有
DMPE(
DMPE =我2 PCH 2 CH 2 PME 2)给出的加合物W(CH 2森达3)3(≡CSiMe 3)(
DMPE- P)(图4a),其经历很少观察到可逆变换到其双-亚烷基互变异构体W(CH 2森达3)2(═CHSiMe 3)2(
DMPE- P)(图4b)通过α-H迁移。4a和4b中的
DMPE
配体均包含一个悬空的P原子(P)。热力学和动力学研究4A ⇌ 4B交换表明它与Δ稍稍吸热ħ °= 5.1(1.1)千卡/摩尔和Δ小号°= 24(4)EU; Δ ħ 1 ⧧ = 7.5(0.9)千卡/摩尔,Δ小号1 ⧧ = -51(2)欧盟用于图4a → 4B正向反应; Δ ħ -1 ⧧ = 2.0(0.8)千卡/摩尔,Δ小号-1 ⧧ = -76(1)EU在图4b →4a发生逆反应。活化熵的主要贡献者到交换的活化障碍:Δ g ^ 1