Fluorenyl complexes

In contrast to these data the later investigations by Beletskaya and coworkers [13, 14] showed that ar -complexes are formed in the reactions of fluorenyllithium with LnCl3 independently of the reagent ratio  

All compounds are very sensitive to oxygen and are quite soluble in THF and aromatic hydrocarbons (Table IV.2). The deuterolysis of complexes leads to the isolation of monodeuterofluorene. 

The analysis of the IR and H NMR spectra allowed the authors to suppose the bridged structure of complexes in which fluorenyl groups are a-bonded with the Ln atom. 

The identity of IR spectra of obtained complexes indicates the invariability of the fluorenyl fragment structure in all compounds. The band at 738 cm testifies that the substituent is in C(9) position of fluorene, and the bands at 1045-1050 and 880-890 cm testify the presence of THF coordinately linked with the Li atom. 

There is a description of only one complex with the titled ligand C )2CtC 2 [18]. The special features of its synthesis and the properties are considered in Chapter XL 

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The weak interactions that may exist between group 2 cations and anionic hydrocabyl ligands are demonstrated in the metal-in-a-box compounds such as [M(THF)6][Me3Si(fluorenyl)]2 (M = Ca 159 or Mg), which are formed by the addition of THF to solutions of the bis(fluorenyl) complexes in non-polar solvents. The box may be completed by the presence of aromatic molecules, as in 159 (Figure 84). The disruption of the metal-carbon bonds is thought to stem from a combination of robust M-THF interaction, the stability of the free [Me3Si(fluorcnyl)] ion, and the formation of numerous C-H- -7r interactions between THF and the anions. These and related examples are reviewed elsewhere. 

In solution, NMR investigations of fluorenyl complexes give rise to only seven C signals, either due to a symmetric position of the lithium cation relative to the car-banion framework or to fast exchange on the NMR time scale under the experimental... 

Temperature-dependent lineshape changes were observed in an early study of the fluo-renyllithium(TMEDA) complex. A detailed study by lineshape analysis, which was also applied to the TMEDA complex of 2,3-benzofluorenyllithium(TMEDA) (Figure 29f, yielded barriers AG (298) of 44.4 and 41.9 kJmoD for the 180° ring flip in these systems, respectively . A second dynamic process, which was detected via the temperature dependence of, the spin-lattice relaxation time in the rotating frame, is characterized by barriers of 35.1 and 37.6 kJmoD, respectively, and may be ascribed to the ring inversion process. For the fluorenyl complex, a barrier AG (298) of 15.9 kJmoD for the methyl rotation in the TMEDA hgand was determined from temperature-dependent NMR spectra of the deuteriated system. 

The log K value for the formation of the Na+-fluorenyl complex with tetraglyme, CHs(OCH2CH2)40CH3, is reported to be over 3 log units lower than that of the corresponding complex with 4 -methylbenzo-15-crown-5 in tetrahydrofuran (18, 36). 

Fluorenide derivatives, alkali compounds, 2, 13 Fluorenyl-amido complexes with Ti(IV), 4, 438, 4, 455 with Zr(IV), 4, 788 Fluorenyl complexes... 

Fluorenyl- /-fluorenyl complexes, with Ti(IV), 4, 406 Fluorenyl hafnocene dichlorides, synthesis, 4, 943 Fluorenyl zirconocene dichlorides, synthesis, 4, 943 Fluorescence resonance energy transfer, in high-throughput catalyst discovery, 1, 358 Fluorescent sensors, Pt acetylenes as, 12, 472... 

Germanium-bridged complexes, with Zr(IV) and Hf(IV) cyclopentadienyl complexes, 4, 967 fluorenyl complexes, 4, 974 indenyl complexes, 4, 972... 

Recent work of Boisson et al. focuses on silylene-bridged Nd complexes of the type depicted in Scheme 10. The respective bis fluorenyl complex [Me2Si(Ci3H8)2]NdCl [307] and the mixed Cp/fluorenyl complex [Me2Si(C5H4) - (Ci3H8)]NdCl [308,309] have been described. The work on silylene-bridged Nd sandwich complexes performed by Boisson et al. is reviewed in [310]. 

Errors can be introduced in several ways, for the indenyl as well as for the fluorenyl complexes ... 

Organometallic complexes such as tris, bis and monocylopentadienyl complexes, cyclooctatetraenyl complexes, cyclopentadienyl-cyclooctatetraenyl complexes, indenyl complexes, fluorenyl complexes, complexes with other aromatic ligands, callixerene complexes, NMR spectroscopy of organometallic complexes, vibrational spectra, and catalytic applications form the theme of the sixth chapter. 

The interaction of bis(pyridinium)cerium hexachloride with Na[Cp] was claimed to produce Ce(Cp)4 and similar reactions afforded the indenyl and fluorenyl complexes. Tris(cyclopentadienyl)cerium chloride and bis(indenyl)cerium dichloride were also claimed. This work is not repeatable and the Ce(Cp)4 has been shown to be Ce(Cp)3(THF). 

Fluorenyl complexes of divalent ytterbium, (Ci3H9)2Yb(L) (L = THF, n = 2 L = DME, n= 1), have been prepared by reaction of YbI2(THF)2 with 2equiv. of KCi3H9 as well as by reaction of (CioH8)Yb(THF)2 with fluorene in THF (Scheme 168).260... 

The synthesis of the PhP-bridged bis(fluorenyl) complex 1196 is outlined in Scheme 282.923 Its activity in the MAO-co-catalyzed polymerization of ethylene is substantially lower than that of the carbon- or silicon-bridged analogs this decrease has been attributed to the increased electron density at the metal center effected by the PPh bridge. 

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