The synthesis, characterization and reactivity of some mononuclear hydrocarbyl compounds of iron

Abstract

Mononuclear hydrocarbyl compounds of the type LnM(CH2)nCH:CH2 (L"M : Cp*Fe(CO)2 and CpFe(CO)2, n: 2-4,6), Cp(CO)zFe(CH2)nOH (n : 4-6,8) and Cp*(CO)2Fe(CH2)+OH have been synthesized. All these compounds have been l3 fully characterized using analytical techniques such as[R, H and C NMR spectroscopy, microanalysis and mass spectrometry The results of some activity studies on the above hydrocarbyl compounds are reported in this thesis. For example, the reactivity of the r'1l-alkenyl compounds Cp (CO)2Fe(CH2).CH=CHZ (n: 2 and 3) to hydrozirconation was studied. Although the expected binuclear hydrocarbyl compounds Cp(CO)2Fe(CH2)na2Zr(Cl)Cpz (n: 2 and 3) were not isolated, their presence in solution were detected by carrying out insitu reactions. The n1-alkenyl compounds were also subjected to a p-hydride abstraction reaction. This afforded a series of cationic n2-diene compounds with general formula {Cp(CO)zFe(CnH2n-2) } PF6. Some of the reactions of the w-hydroxyalkyls were also investigated. The bromination of these hydroxy species leads to the formation of w-bromoalkyls of the type Cp(CO)2Fe(CH2)'Br (n 4 and 8). The w-hydroxyalkyls cp(co)2Fe(CH2)nOH (n : 4-6,8) were reacted with trifluoroacetic acid which results in iron-carbon cleavage. Finally the reaction of some w-hydroxyalkyls with triflic anhydride gives different results depending on the type of solvent employed. In THF a metal containing polyether is isolated as the major product, while in diethyl ether the major species isolated is a o-chloroalkyl of the type Cp(Co)2Fe(CH2)nCl (n : 4 and 5)' In the case of the reaction in THF, a small amount of the binuclear hydrocarbyl compound [CpFe(Co)z]{p-(CHz)a}can be isolated if [CpFe(Co)z] is added to the reaction mixture