ISSN:
1572-901X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary [Fe2(η-Cp)2(CNAr)4] (2) (540-01, C6H4Me-2, C6H4Et-2, C6H3Me2-2,4, C6H3Me2-2,6, C6H3(Me)Et-2,6, C6H3Et2-2,6 or C6H3 i-Pr2-2,6) react with I2 to give [Fe(η-Cp)(CNAr)2I], but with Br2[Fe(η-Cp) (CNAr)3]+ salts are the only products; IBr gives a mixture of the two. With SnX2 (X = F, Cl, Br or I) in refluxing n-butanol, (2) gives isolable [{Fe(η-Cp)(CNAr)2}2SnX2] only when the CNAr ligands have two ortho substituents, otherwise decomposition occurred. When X = F, [Fe(η-Cp) (CNAr)2SnF3] was also obtained from this reaction. Attempts to prepare [Fe(η-Cp)(CNAr)2X] (X = Cl or Br) by reaction of (2) with HX in the presence of air gave rather unstable products which with SnX2 formed [Fe(η-C5H5)-(CNAr)2SnX3]. Similar compounds, [Fe(η-Cp) (CNAr)2 SnX2I], were obtained from [Fe(η-Cp)-(CNAr)2I] and SnX2 (X = Cl or Br but not I). All of these complexes are much less stable than their Fe(η-Cp)(CO)2 counterparts; all decompose in solution to [Fe(η-Cp)(CNAr)3]+ which then break down to unidentified species. X-ray diffraction studies show that in [Fe(η-Cp)(CNC6H3-i-Pr2-2,6)2I] and [{Fe(η-Cp)(CNC6H3Me2-2,6)2}2SnBr2] there is pseudo-octahedral coordination about Fe. In the latter there is also distorted tetrahedral coordination about Sn so that its structure is very similar to that of [{Fe(η-Cp)(CO)2}2SnCl2]. Spectroscopic studies show that in all complexes rotation of the aryl rings of the CNAr ligands cannot be slowed in solution, and that there is free rotation about all 540-02 bonds.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00136416
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