criterion is confirmed by X-ray analysis of IIIb. Exo-isomers, IIIb,c, were obtained by alkylation of the η6-fluorenylchromium tricarbonyl anion (I) with the corresponding halides RX in tetrahydrofuran (THF) at low temperature. Endo-isomers (Vb,c) have been obtained by alkylation of the η6-fluorenylchromium tricarbonyl anion (II) with subsequent thermal rearrangement of intermediate σ-organometal derivatives
一种方法,以确定的9-取代的芴铬三羰基复合物的几何构型(η 6 -9-RC 13 ħ 9)的Cr(CO)3,其允许一个之间进行区分外型-异构体式(IIIa-e)和内-异构体(Va–e)被提议;a,R = CH 3;b,R = CH 2 HC 6 H 5,c,R = D;d,R = tC 4 H 9; n =1。e,R = C 6 H 5。此方法基于测量芳族溶剂从CDCl 3传递到C时在1 H NMR光谱中诱导的化学位移6 D 6解决方案(ASIS效果)。该标准的有效性通过IIIb的X射线分析得以证实。外型-异构体,IIIb族,C,是由η的烷基化得到6 -fluorenylchromium三羰基阴离子(I)与相应的卤化物RX在四氢呋喃(THF)在低温下。远藤-异构体(VB,C)已经由η的烷基化得到6与没有其隔离中间σ-有机金属衍生物(IV)的后续热重排-fluorenylchromium三羰
Synthesis and conformations of chromium tricarbonyl substituted diarenes
作者:Thomas E. Bitterwolf、Robert Herzog、Paul D. Rockswold
DOI:10.1016/s0022-328x(00)98976-9
日期:1987.2
The metallation of a series of seven planar and bent diarenes has been examined to determine the conformations of the mono- and dimetallated products. It has been found that bent diarenes can be metallated on either the convex (syn) or concave (anti) faces of the arene. In the absence of other directing groups, metallation at the concave face is favored. Dimetallation of planar diarenes results in
已经检查了一系列七个平面和弯曲的二芳烃的金属化,以确定单金属化和双金属化产物的构象。已经发现弯曲的芳烃可以在芳烃的凸(syn)或凹(反)面上金属化。在没有其他导向基团的情况下,在凹面的金属化是有利的。平面芳烃的双金属化导致排他的反金属化。弯曲的芳烃的双金属化主要产生反式异构体,但也观察到凸面的顺式双金属化。使用1 H和13 C NMR光谱证据进行了构象分配。
Effect of Enhanced Electron Withdrawal on the Cohesion of Cr‐Pd Hemichelates
new trimetallic Cr‐Pd hemichelates containing a fluorenyl moiety and two trans arene‐bound Cr(CO)3 moieties were synthesized and fully characterized. Their molecular structures obtained by X‐ray diffraction analysis do not show major differences – in interatomic bond lengths within the Pd coordinationsphere – when compared to previously reported bimetallic analogues. Theoretical investigations were