The organometallic Lewis acid [(η5-C5H5)(CO)2Fe]BF4 reacts with excess dry diethyl ether at low temperatures to form the novel labile complex [(η5-C5H5)(CO)2Fe(OEt2)]BF4 which in turn serves as a precursor in the syntheses of various cationic dicarbonylcyclopentadienyliron complexes. The reactions of [(η5-C5H5)(CO)2Fe(OEt2)]BF4 with various 1-alkylamines, α,ω-diaminoalkanes, N-heterocyclics and heterofunctional amine ligands, as well as olefins, have been investigated. Reactions with 1-alkylamines and α,ω-diaminoalkane ligands lead to a series of novel monuclear and dinuclear complexes of the types [(η5-C5H5)(CO)2FeL]BF4 and [{(η5-C5H5)(CO)2Fe}2(μ-L)](BF4)2, respectively. The reaction of [(η5-C5H5)(CO)2Fe(OEt2)]BF4 with N-heterocyclic ligands such as 1,3,5,7-tetraazaadamantane (HMTA) and 1,4-diazabicyclo[2.2.2]octane (DABCO) give dinuclear complexes [{(η5-C5H5)(CO)2Fe}2(μ-L)](BF4)2 and monuclear complexes [(η5-C5H5)(CO)2FeL]BF4 (L = HMTA, DABCO). Its reaction with 1-methylimidazole (1-meIm) affords only the monuclear complex [(η5-C5H5)(CO)2Fe(1-meIm)]BF4 in which the coordination of 1-methylimidazole is via the sp2-N. The reaction with heterofunctional amine ligands is highly regioselective with the cation [(η5-C5H5)(CO)2Fe]+ showing higher affinity for NH2 than π-bonded, O or CN functionalities. Besides amines, [(η5-C5H5)(CO)2Fe(OEt2)]BF4 reacts with olefins and HCOOH to form complexes of the type [(η5-C5H5)(CO)2Fe(η2-olefin)]BF4 and [{(η5-C5H5)Fe(CO)2}2(μ-OCHO)]BF4, respectively. For comparison of steric and electronic effects, analogous pentamethylcyclopentadienyl amine complexes were synthesized from the THF complex [{η5-C5(CH3)5}(CO)2Fe(THF)]BF4. The reaction of 3-aminoprop-1-ene with the etherate complexes [(η5-C5R5)(CO)2Fe(E)]BF4 (R = H: E= Et2O; R = CH3: E = THF) led to air stable complexes [(η5-C5R5)(CO)2Fe(NH2CH2CHCH2)]BF4 (R = H, CH3), which in turn react with a mole equivalent of the etherate complexes to give dinuclear complexes of the type, [(η5-C5R5)(CO)2Fe(NH2CH2CHCH2)Fe(CO)2(η5-C5R'5)](BF4)2 (R not necessarily equal to R'). They also undergo halogenation to give the chiral dihalopropylamino complexes [(η5-C5R5)(CO)2Fe(NH2CH2CH(X)CH2(X))]BF4 (R=H, CH3; X = Cl, Br). The reaction of the dinuclear complex [{(η5-C5H5)(CO)2Fe}2(NH2CH2CHCH2](BF4)2 with NaI in acetone gives [(η5-C5H5)(CO)2Fe(NH2CH2CHCH2)]I and [(η5-C5H5)Fe(CO)2I]. All these complexes have been fully characterized by 1H NMR, 13C NMR, IR spectroscopy and elemental analysis. The mass spectra of 1-aminoalkane and diaminoalkane complexes have also been recorded and are discussed. The structures of 16 synthesized compounds have been confirmed by single crystal X-ray crystallography. Most of the amine complexes are water-soluble and some undergo counteranion exchange with sodium tetraphenylborate in both aqueous and organic media to give BPh4- salts. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.

No description available.

A number of iron carbonyl complexes has been prepared from the mixed ligands F₄AsP and F₆AsP and the iron carbonyls Fe(CO)₅ , Fe₂(C0)₉ and Fe₃(C0)₁₂. They are isolated by chromatographic methods and characterized by spectroscopic techniques. These complexes, which can be classified into ten groups, are the only series of iron complexes of organo-bridged mixed ligands known so far. The complex (F₄AsP)₂Fe(CO)₃ is probably the first example of a L₂Fe(CO)₃ compound in which the two polydentate ligand molecules behave as mono-dentates and occupy the two trans positions of a trigonal bipyramidal structure. The isolation of P-bonded complexes F₄AsPFe(CO)₄, F₆AsPFe(CO)₄ and (F₄AsP)₂FeCO)₃ and the complete absence of the corresponding As-bonded complexes clearly illustrate that the PPh₂ group is a better coordinating group than the AsMe₂ⁿ group. The novel complexes LmLFe₂(CO)₅ (Lm = monodentate ligand), LbLFe₂(CO)₄ (Lb = bridging group) and Lc LFe₂(CO)₄ (Lc = chelating group) are derived from the very stable LFe₂(C0)₆ complexes (L = F₄AsP, F₆AsP). The structures of these are unusual in that they contain two types of ligand molecules, one acting as a tri-dentate group while the other acting as a mono-dentate group, a bridging group or a chelating group. It is interesting to note that the F₄AsP forms two complexes of the same molecular formula, namely, (F₄AsP)b F₄AsPFe₂(CO)₄ and (F₄AsP)c F₄AsPFe₂(CO)₄, which can be distinguished by infrared and Mossbauer data. Moreover, two additional complexes of the same molecular formula, (F₄AsP)b F₆AsPFe₂(CO)₄ and (F₆AsP)c F₄AsPFe₂(CO)₄ ՚ are obtained from F₄AsP and F₆AsP The method of preparation and the spectroscopic properties of the mixed ligands and their complexes are discussed. The factors which affect the formation of the iron carbonyl complexes are investigated and the possible reaction mechanisms for their formation are proposed. / Science, Faculty of / Chemistry, Department of / Graduate

No description available.

published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

A study of the anodic polarography of catechol in 0.100 F sodium perchlorate is presented. A new wave is observed in alkaline solutions which is different from the simple oxidation wave of catechol to ortho-quinone observed by previous workers. The importance of buffer materials is discussed and a possible explanation of the new wave is suggested. A study of the polarography behavior of Fe(II) and Fe(III) in the presence of catechol is reported. In the case of reduction of Fe(III) in the presence of catechol, two steps occur at about -1.5 and -1.8 volts (vs. SCE) at pH higher than 11.6 corresponding to one electron reduction of Fe(III) to Fe(II) and successive two electron reduction of Fe(II) to Fe(s). At lower pH these two steps are too close together to be resolved. An oxidation wave and a reduction wave are recorded for the electrolysis of Fe(II) in the presence of catechol: the oxidation wave is observed between pH 7 and 12.3. The curve showing dependence of the limiting current on pH is similar to the distribution curve of Fe(cat). It is therefore suggested that only Fe(cat) is oxidized and observed here. The reduction wave of Fe(II) in the presence of catechol is irreversible and shifted from -1.5 to -1.8 volts upon complex formation. A calculation of formation constants, 81 and 82, was achieved according to an equation which relates the shifts of halfwave potential to the formation constants.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--University of Hong Kong, 2007. / Also available in print.

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1912. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed April 20, 2009) Includes bibliographical references.

Dissertation (Ph.D.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references.