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M.Sc. / Please refer to full text to view abstract

The anionic tridentate chelating ligands [MeGa(pz)₃]⁻, [MeGa(dmpz)₃]⁻, and [MeGa(mpz)₃]⁻ have been synthesized and their coordinative properties studied. The [MeGa(pz)₃]⁻ ligand acts as a six-electron chelating ligand to divalent transition metal ions giving complexes of the type [MeGa(pz)₃]₂M (M=Mn,Co,Ni,Cu,Zn), believed to possess an octahedral MN₆ core. The ligand also forms numerous carbonyl complexes with Mn, Mo and W. The tridentate chelating nature of this new ligand has been demonstrated through a crystal structure determination of the complex [MeGa(pz)₃]Mo(CO)₂(n³-C₃H₅). The [MeGa(dmpz)₃]⁻ ligand also forms carbonyl complexes of Mn, Mo and W. The ready conversion of this ligand to the less sterically demanding tris-chelating "hydroxy" ligand [MeGa(dmpz)₂(OH)]⁻ occurs in the attempted synthesis of "n³-allyl" complexes [MeGa(dmpz)₃]M(CO)₂ " n³-allyl" (where M=Mo or W, "n³-allyl"=n³-C₅H₅, n³-C₄H₇). The tridentate chelating nature of this "hydroxy" ligand is conclusively demonstrated in the crystal structure determination of the complex [MeGa(dmpz)₂(OH) ]Mo(C0)₂(n³-C₄H₇) . The [MeGa(mpz)₃]⁻ ligand forms transition metal complexes of the type [MeGa(mpz)₃]₂M (M=Co,Ni) and also carbonyl complexes of Mo and W. Less definitive results were obtained with this ligand, as characterization of the resulting complexes was complicated by the inability to separate the isomers possible for each complex The synthesis of the [H₂B(OCH₂CH₂NR₂)(pz)]⁻ (R=H, Me) ligands and their reaction with divalent transition metal ions is also described. In this case, the only products isolated were the previously characterized [H₂B(pz)₂]₂M and [HB(pz)₃]₂M (M=Co,Ni, Cu,Zn) complexes. Finally, details of the synthesis and characterization of the [R₂Ga(CH₃C0₂)] and [R₂Ga(C₄H₈NC0₂)] (R=Me,Et) compounds are given. The crystal structure of the [Me₂Ga(C₄H₈NC0₂)] derivative consisted of monomeric units linked to two others by weak Ga-0 bonds to form a chain-like polymeric structure. The gallium atom in this compound is five-coordinate and has distorted trigonal bipyramidal geometry. / Science, Faculty of / Chemistry, Department of / Graduate

Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

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.

No description available.

The ligands 2-cyanocyclopentyldiphenylphosphine and 2-cyanocyclohesyldiphenylphosphine were synthesized from 1-cyanocyclopentene and 1cyanocyclohexene by addition reactions using diphenylphosphine and aqueous base as the catalyst. These ligands reacted with Pt(II) and Pd(II) salts to yield complexes of the stoichiometry MX2L2 (X = C1, Br). In these complexes the ligands were found to function as monodentate phosphines. Infrared spectroscopic evidence suggested that the platinum complex was of cis and the palladium complexes were of trans geometries.The reactions of the ligands 2-cyanocyclopentyldiphenylphosphine and 2-cyanocyclohexyldiphenylphosphine or the ligand 2-cyanoethyldiphenylphosphine with the complexes dimethyyl(cyclooctadiene)platinun(II) or methyl) (chloro) (cyclooctadiene) platinum(II) resulted in complexes of the stoichiometries Pt(CH3)2L2 and Pt(CH3)(C1)L2. In these complexes the ligands also functioned as monodentate phosphines. hmr and far infrared spectroscopic evidence suggested that the dimethylplatinuin(II) complexes were cis and the (methyl)(chloro)platinum(II) complexes were trans.A complex of the stoichiometry Pd2Cl4(Ph2PC6H10CN)2 was isolated from the reaction of a 1:1 mole ratio of PdC12 with Ph2PC6H10CN. Far infrared and Raman spectroscopic evidence 'suggested that the complex was a chlorine bridged dieter with the ligands at symmetrical positions. The nitrile groups in this complex reacted rapidly with alcohols to yield monomeric imino ether complexes.The Pt(CH3)(C1)L2 complexes reacted with AgPF6 to yield cationic salts of the stoichiometry [Pt(CH3)L2]n+n with one ligand in each [Pt(CH3)L2]+ unit presumably serving as a bridging ligand and the other as a monodentate phosphine. The coordinated nitrite groups in these complexes reacted slowly with methanol to yield amino ether complexes.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. Includes bibliography.

Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.