STUDIES ON cis-trans-ISOMERIZATION AND REACTION KINETICS OF A μ, η~2-VINYL LIGAND IN A TRIOSMIUM CLUSTER

The dihydride cluster H_2O_(s_3)(CO)_(10) reacts with ethyne to give a cis-adduct [O_(s_3)H(μ,η~2-CH=CH_2)(CO)_(10)]. The high deuterated cluster D_2O_(s_3)(CO)_(10), the reaction of D_2O_(s_3)(CO)_(10)with ethyne C_2H_2 to form the vinyl product cluster [O_(s_3)D(μ, η~2-CH=CHD)(CO)_(10)], and thereaction of H_2O_(s_3)(CO)_(10) with the deuterated ethyne C_2D_2 to form [O_(s_3)H(μ,η~2-CD=CDH)(CO)_(10)] have been reported primarily in this paper. The two cis-adducts undergo cis-trans-isomerization of μ,η~2-vinyl ligands under a small amount of the nucleophile pyridine. Usingthe combination of deuteration and dynamic ~1H,~2H NMR spectra, we report the experimen-tal evidence determined by the dynamic ~1H, ~2H NMR spectra, mechanism, and kinetic dataof the isomerization.     

三核锇原子簇中μ,η~2-乙烯配位基顺反异构化及其反应动力学研究

含氢原子簇化合物H_2Os_3(CO)_(10)与乙炔反应生成顺式加成物[Os_3H(μ,η~2-CH=CH_2)(CO)_(10)]。本文首次报道高含量氘代原子簇D_2Os_3(CO)_(10)与乙炔反应生成合乙烯配位基的氘代原子簇[Os_3D(μ,η~2-CH=CHD)(CO)_(10)],H_2Os_3(CO)_(10)与氘代乙炔反应生成[Os_3H(μ,η~2-CD=CDH)(CO)_(10)],它们在微量亲核试剂吡啶作用下发生μ,η~2-乙烯配位基的顺反异构反应。本文用同位素氘代和~1H,~2H NMR动态波谱联用方法,研究了上述反应和异构化过程,提出了顺反异构化的核磁共振动态波谱证据、反应机理和动力学数据。     

丙烯氢羟甲基此反应——Ⅰ.铁原子簇的催化作用

丙烯Reppe反应制丁醇自1953年Reppe等人发现以来,催化剂主要是铁、钴、铑三体系,都前后分别实现了工业化生产。从反应工艺条件、催化剂的各项性能指标、原料资源等方面考虑,各有利弊。因此,深入研究各簇合物在此反应中的催化作用,开拓具有应用前景的新型催化剂,在实践和理论上都有重要的意义。我们考察了铁系在此反应中的催化性能,从动力学特征到红外光谱分析都发现了某些过去未曾报导的重要结果,证实了G.H.Olive等人的看法:铁系在丙烯Reppe反应中的催化作用机理从活性物种到动力学还要做更多的研究工作。     

盖帽三核钴羰基簇合物(μ_3-CH_3C)Co_3(CO)_7(μ-PPh_2CH_2PPh_2)和(μ_3-CH_3C)Co_3(CO)_9的质谱研究

本文从结构化学角度,阐述了标题化合物的EI质谱断裂行为。这些化合物的分子离子基本上按分步断裂分别失去羰基,直至获得[CH_3CCo_3(PPh_2CH_2PPh_2)]~+和[CH_3CCo_3]~+。然后,这些残基和含膦配体继续断裂,失去Ph、PhP、Ph_3P、C_7H_7、C_6H_6、C_2H_2、H_2和Co等,生成各种相应的三核、二核和单核钴的碎片离子。     

具有活性的六核锇排状原子簇的合成、结构和反应性能研究

本文报道六核锇排状平面原子簇的合成和活化。三核锇活性原子簇[Os_3(CO)_(10)(MeCN)_2]在PdCl_2催化作用下发生偶联反应,生成具有活性的六核锇排状原子簇[Os_6(CO)_(20)(MeCN)]和[Os_6(CO)_(19)(MeCN)_2]。用氧化三甲胺(Me_3NO)对活性原子簇中羰基配位基进行多重活化,获得一系列具有活性的六核锇排状原子簇[Os_6(CO)_(21-n)(MeCN)_n](n=1—5)及其相应的配位体取代反应产物[Os_6(CO)_(21-n)(P(OMe)_3)_n](n=1—5)。并通过红外光谱、核磁共振波谱和质谱等数据对上述排状原子簇进行结构表征,同时就其排状平面结构和反应性能特点进行讨论。     

STUDIES ON SYNTHESIS, STRUCTURE AND REACTIVITY OF ACTIVATED Os_6 RAFT-LIKE CLUSTERS

In this paper we report the synthesis and activation of OS-6 raft-llke planar clusters. The activated OS-66 raft-like clusters [OS-66(CO)_(20)(MeCN)] and [OS-66(CO)_(19) (MeCN)_2] have been prepared by involving PdCl_2 as catalyst. Trimethylamine oxide (Me_3NO) has been used as an activation reagent to oxidize several carbonyl ligands coordinated in the activated clusters and to get a series of activated OS-66 raft-like clusters [OS-66(CO)_(21-x)(MeCN)_x] (n = 1--5) and corresponding substituted clusters [OS-66(CO)_(21-x)(P(OMe)_3)_x] (n=1--5). The structures of these OS-66 raft-like clusters have been characterized by the infrared spectra (IR), nuclear magnetic resonance spectra (NMR) and mass spectra (MS), and the characters of the raft-like planar structure and reactivity above have also been discussed in this paper.     

三核钴原子簇的活化和含膦配位基三核钴原子簇的合成

本文报导氧化三甲铵(Me_3NO)的乙腈溶液在室温下对三核钴羰基原子簇进行有效活化,生成相应的准配位不饱和原子簇(μ_3-CR)Co_3(C0)_(9-n)(MeCN)_n(R=CH_3、Ph、H、Cl,n=1,2),然后进行配位基取代反应,生成一系列台单齿膦配位基PPh_3和含双齿膦配位基dppm[Bis(diphenylphosphino)methane]的三核钴原子簇.在钴原子簇体系中应用这种化学活化方法,目前尚未见文献报导.