兩種四芽配位基PS3”和PS3*被用來與高價釩金屬起始物反應，以便能夠了解高價釩硫化學的作用，在這份研究中，我們鑑定了五種釩硫錯合物，分別為: [V(PS3”)2][NEt4] (1a), [V(PS3*)2][NPr4] (1b), [VIV(PS2”SH)(PS3”)][PPh4] (2a), [VIV(PS3*)(PS2*SH)][NPent4] (2b), 與[VIV(PS3*)2] [(NPr4)2] (3)。它們與空氣的反應活性已被探討，其結果可由紫外光可見光光譜、與質譜等方法驗證。七配位之[VIV(PS2”SH)(PS3”)]- (2a)與[VIV(PS3*)(PS2*SH)]- (2b)可與空氣反應進而生成[V(PS3”)2]- (1a)與[V(PS3*)2]- (1b)。八配位之[VIV(PS3*)2]2- (3) 可與空氣或[Fe(C5H5)2][BF4]進行一個電子的氧化進而生成化合物1b。
化合物1a與1b為一個具有自由基四價釩硫錯合物與五價釩硫錯合物的共振型式存在的特性之錯合物，可以與水反應而進行氧-氫鍵斷裂生成化合物2a和2b。1a與1b亦可與甲醇反應分別進行碳-氧鍵和氧-氫鍵斷裂，各別生成化合物2a, [VIV(PS3”)(PS2SCH3”)]- (4a)與2b, [VIV(PS3*)(PS2SCH3*)]- (4b)。
化合物1a與一系列的受質，如水、甲苯、CH3CN、fluorene與THF之動力學研究已被探討。從動力學同位素效應中可得知，氧-氫鍵的斷裂為速率決定步驟。有趣的是化合物1a可斷裂較強的氧-氫鍵卻不能斷裂較弱的碳-氫鍵，此發現我們推測藉由受質與化合物1a所產生的氫鍵之輔助作用造成預排列的現象，進而降低了活化位能障礙。

In our effort to understanding high-valent vanadium sulfur chemistry, two tris(thiolato)phosphine ligands, [PS3”]H3 and [PS3*]H3 has been untilized to interact with high-valent vanadium species.([PS3”]H3=[P(C6H3-3-Me3Si-2-S)3]3-. [PS3*]H3=[P(C6H3-3-Ph-2-S)3]3-). At this work, several five vanadium-thiolate complexes have been obtained and characterized. They are [V(PS3”)2][NEt4] (1a), [V(PS3*)2][NPr4] (1b),[VIV(PS2”SH)(PS3”)][PPh4] (2a), [VIV(PS3*)(PS2*SH)][NPent4] (2b), and [VIV(PS3*)2] [(NPr4)2] (3). The reactivity of them with air has been explored. The evidences were supported by Ultraviolet-visible spectroscopies and ESI-MS studies. The hepta-coordinated [VIV(PS2”SH)(PS3”)]- (2a), and [VIV(PS3*)(PS2*SH)]- (2b) proceed air oxidation to form the octa-coordinated [V(PS3”)2]- (1a) and [V(PS3*)2]- (1b), respectively. The octa-coordinated [VIV(PS3*)2]2- (3) can be oxidized via one electron oxidation to form complex 1b by air oxidation or [Fe(C5H5)2][BF4] oxidation.
From ESI-MS studies, complex 1a and 1b, species with resonance forms between V(V)-thiolate and V(IV)-thiyl radical, can reacted with H2O and form 2a and 2b by homolytic cleavage of the O-H bond. In addition, complex 1a and 1b also reacted with methanol via homolytic cleavage of O-H bond and C-O bond. Consequently, it led to the formation of 2a, [VIV(PS3”)(PS2SCH3”)]- (4a), and 2b, [VIV(PS3*)(PS2SCH3*)]- (4b), respectively.
The kinetic studies of 1a with a series of substrates, such as H2O, toluene, CH3CN, fluorene and THF, have been investigated. From the kinetic isotope effect (KIE), O-H bond cleavage in H2O is an important component of the rate-determining step. It is interesting that 1a prefers to cleave stronger O-H bonds rather than C-H bonds. This finding was proposed that the preorganization step via the assistant of the hydrogen bonding interaction between substrates and 1a plays a key role which reduces the activation energy barrier.

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