Synthesis and properties of sterically congested cyclopentadienes and their transition metal complexes
作者:T.Jeffrey Clark、Christopher M. Killian、Sanjay Luthra、Terence A. Nile
DOI:10.1016/0022-328x(93)83365-3
日期:1993.12
The synthesis of 1,3-dialkyl substituted cyclopentadienes, C5H4RR′, Cp′H (Va–g) (where R and R′ are tert-butyl, iso-propyl, neo-pentyl, cyclohexyl, or 1-methylcyclohexyl) is reported. These are synthesized by the nucleophilic addition of methyl or hydride anions to the corresponding 2-alkyl-6,6-dialkylfulvenes (IIIa–f) followed by hydrolysis. These substituted 1,3-cyclopentadienes have been converted
1,3-二烷基取代的环戊二烯,C 5 H 4 RR',CP'H(Va–g)(其中R和R'为叔丁基,异丙基,新戊基,环己基或1-甲基环己基)。这些是通过将甲基或氢化物阴离子亲核加成到相应的2-烷基-6,6-二烷基富勒烯(IIIa–f)中,然后水解而合成的。这些取代的1,3-环戊二烯已转化为有机金属衍生物例如[CP'Fe(CO)2 ] 2,[CP'M(CO)3本人](MMo或W)和CP' 22Fe。为了研究取代的环戊二烯基配体的空间和电子性质,已经研究了所选配合物的光谱和电化学性质。
Novel thermal rearrangement reactions: rearrangement stereospecificity of complex [Fe2(CO)2(μ-CO)2(μ-t-BuC5H3Me2GeGeMe2C5H3Bu-t)]
2-bis(3-tert-butylcyclopentadienyl)tetramethyldigermane with [Fe(CO)5] in xylene gave the diiron complex [Fe2(CO)2(µ-CO)2(µ-3-t-BuC5H3Me2GeGeMe2C5H3Bu-t-3)] 1 existing as a mixture of cis and trans isomers (1c and 1t) which were separated by preparative TLC. When the two isomers were heated in xylene the cis substrate (1c) rearranged to a trans product [Fe2(CO)4(µ-3-t-BuC5H3GeMe2)2] 2t, while the trans
A novel method for the preparation of heterogeneous metallocene catalysts is described that can be applied for the polymerization of olefins starting with homogeneous metallocene complexes. For this purpose zirconocene dichloride complexes have been prepared containing alkenyl or alkynyl substituents. These complexes can be activated with methyl alumoxane (MAO) and then are incorporated as comonomers
Stable NMR- and EPR-Active 17-Electron Chromium(III) Half-Sandwich Compounds
作者:Oliver M. Heigl、Eberhardt Herdtweck、Stefan Grasser、Frank H. Köhler、Werner Strauss、Harald Zeh
DOI:10.1021/om020229i
日期:2002.8.19
The precursor 8 was synthesized from (t-BuCp)Na and CrCl3(THF)3. The dication 22+ was also obtained electrochemically from [(C5Me5)Cr(CNCH3)4]+[PF6]- (2+[PF6]-), which was synthesized by reaction of [(C5Me5)Cr(C6H3Me3)]+[PF6]- with CNCH3 in 86% yield. Conversely, the dication 72+ could be reduced to 7+ obtained as [PF6]- and [B(C6H5)4]- salts. The crystal structure of 102+[CF3SO3]-2 confirmed the four-legged
通过使用异氰酸酯配体稳定化后,分离出难以捉摸的铬(III)的17电子半三明治。因此,Cp 2 Cr与CF 3 SO 3 H和CNCH 3的反应产生了[CpCr(CNCH 3)4 ] 2+(7 2+)为三氟甲磺酸盐,而[(R n Cp)CrCl 2 ] 2(R = Me,H(分别为3和5),n = 5; R = t -Bu,n = 1(8))与Tl(CF 3 SO 3)给出7 2 +,[(C 5 Me 5)Cr(CNCH 3)4 ] 2+(2 2+)和[(t -BuCp)Cr(CNCH 3)4 ] 2+(10 2+)再次使用三氟甲磺酸酯,收率高达59%。由(t- BuCp)Na和CrCl 3(THF)3合成前体8。指示2 2+也是由[[C 5 Me 5)Cr(CNCH 3)4电化学获得的。] + [PF 6 ] -(2 + [PF 6 ] -),这是通过[(C 5 Me 5)Cr(C 6 H