This thesis describes experimental methods, including in situ X-ray diffraction, especially suited to the study of lithium intercalation systems,and discusses the interpretation of the results obtained in a study of Li[sub=x]TiS₂. A rigid plate and spring model of layered intercalation systems is developed and is used to investigate the role of lattice expansion and elastic energy in layered intercalation compounds. When the elastic energy, calculated using the spring and plate model, is included in the Hamiltonian of a three dimensional lattice gas model for Li[sub=x]TiS₂ good agreement between the experimental results and the theoretical predictions are obtained. Staging, not lithium ordering, is identified as the dominant physical mechanism in Li[sub=x]TiS₂. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The reaction of a number of (trialkylstannyl)copper reagents with 2-alkynoates, N,N-dimethyl-2-alkynaraides and 1-alkynes is described. It has been found that the (trimethylstannyl)copper reagents 14 and 43-46 efficiently transfer the trimethylstannyl group to oc-alkynoates. Reagent 14 (THF, -48°C) provided predominantly the (Z)-3-trimethyl-stannyl-2-alkenoate (22), reagents 44 and 45 (THF, -48°C) afforded essentially exclusively the corresponding (E) isomer 21, while reagents 43 and 46 gave a mixture of isomers. Using the above methodology, ethyl 2-pentynoate was converted into either (Z)- or (E)-3-( tri-n-butylstannyl)-2-pentenoate. The (E) isomer was converted into the vinylstannane 188 which was transformed (MeLi, THF, -20°C) into the corresponding stereochemically homogeneous vinyllithium reagent and elaborated into the acyl portion of (±)-triophamine (172), a diacylguanidine recently isolated from Triopha catalinae. Reaction of 2-alkynoates with excess 44 or 45 (THF, 0°C) afforded, as essentially the only products, (E)-2,3-bis(trimethyl-stannyl)-2-alkenoates (115). One member of this new class of compounds, ester 114 (=115, R = Me, R' = Et) was selectively transmetalated (MeLi, THF, -98°C) and the resultant nucleophilic species was allowed to react with a number of reactive electrophiles to produce esters of general structure 141. / Science, Faculty of / Chemistry, Department of / Graduate

M. Sc. / This study comprises the preparation and characterisation of new cyclopentadienylmolybdenum carbonyl complexes. In addition, an unique isomeric equilibrium as well as the new packing pattern of the known compound of cyclopentadienyltricarbonylmolybdenum bromide is also described. The cyclopentadienylmolybdenum carbonyl complexes have been prepared from precursors of the type [CpMo(C0)3X] which reacts with alkyllithium reagent to -afford [CpMo(CO)3R] compounds. [CpMo(C0)3I] reacts with phenylacetylide lithium to form [Cp(C0) 3MoC-CP11] (1). The X-ray crystal structure of compound 1 has been determined and reveals that the length of the triple bond is somewhat shorter than any of the other known acetylide complexes. Treatment of 1 with the electrophiles CF3SO3CH3 or (CH3)2SO4 gives the cationic complex [Cp(C0)3Mo=C=C(CH3)(Ph)r CF 3S03" (4). [CpMo(C0)3I] reacts with 1,3-dithianyllithium to form [Cp(C0)3Moe(H)SCH2CH2C1121 (2) which can easily be deprotonated on the coordinated carbon. [CpMo(C0) 3I] also reacts with methyllithium to form [CpMo(CO)3CH3] (3) which is a known compound. The reaction of CS2 with 1 which occurs by a (2 + 2) cycloaddition affords [Cp(CO)3MoC=C(Ph)C(=S)S] (5). As we could not alkylate this CS 2 adduct, additional studies with molybdenum compounds in which a CO ligand has been substituted with PPh 3 and PMe3 have been carried out. [CpMo(C0)3I] reacts with PPh3 to form [CpMo(CO)2(PPh3)I] (6), a stable compound, known and well characterised. The compound 6 also reacts with phenylethynyllithium to form [Cp(C0)2(PPh3)MoCE---CPh] (7). Treatment of 7 with CS2 leads to [Cp(C0)2(PPh3)MoC=C(Ph)C(=S)] (8). [CpMo(C0)3I] reacts with PMe3 to yield two isomers [CpMo(CO)2(PMe3)I] (cis-9) and (trans-9). These two isomers were isolated and we observed that in solution the cis isomer was slowly transformed into the trans isomer which indicated the existence of an isomeric equilibrium. Cis-9 react: with phenylethynyllithium to form [Cp(C0)2(PMe3)MoCCP11] (11). Finally, during unsuccessful attempts to react the dimeric compound [CpMo(CO)3]2 with alkyl and aryllithium, the known compounds [11 5-CpMo(C0)3C1] and [re-CpMo(C0)3Br] (12) were produced in crystalline form. The X-ray crystal structure of the neutral complex 12 has been determined and the molecular structure has bond distances and angles very similar to the literature values of the same compound. However, the compound 12 exhibits a different packing pattern in the unit cell.

No description available.

Thesis (Ph. D.)--University of Adelaide, 1985. / Includes bibliographical references (leaves 204-208).

published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

No description available.

D.Sc. / This study involves the preparation and characterization of new amino(thio) carbene complexes of gold(I) and gold(III). In addition the reactivity of bis(thiazolyl) aurate and the above mentioned carbene complexes are also described. Various thiazolyllithium reagents reacted with [AuCl(tht)] to yield bis(thiazolyl) aurate complexes of gold(I) which were isolated in crystalline form. These crystals contained solvent of crystallization and no structural determination of these aurates were possible. The latter compounds readily reacted with elemental sulphur by insertion of a sulphur atom into one of the Au-C bonds thereof Subsequent reaction with one molar equivalent of CF 3S03CH3 or CF3SO3H produced either carbene, [Au(CNRYS)(SC=NY§)] (Y = CCH 3=CH, C4H6; R = H, CH3), or thione, [Au(S=h‘TRY)(C=NYS)], complexes of gold(I) which spontaneously decomposed into gold(I) polymers ([Au(C=NYS)]. or [Au(S&=NY)].) and organic products (C=NYS or S=CNRYS). In an attempt to isolate the above-mentioned carbene or thione complexes bis(thiazolyl) aurate complexes were treated with two molar equivalents of CF3S03CH3 or CF3SO3H after sulphur insertion. Rather than the expected mixed carbene thione complexes, [Au(elsTRY§)(S=eNRY§)]CF 3S03, homoleptic rearrangement produced bis(carbene) complexes of gold(I) with unexpected counterions (Cl instead of CF 3SO3). Reaction of lithiated mercaptobenzothiazole with [AuCl(tht)] yielded a bis(thiolate) complex of gold(I), [Au(SC=NC 6H4 S-0)2]Li. Alkylation or protonation of this modified aurate complex resulted in the formation of gold polymers, [Au(S=NC 6H4 -0)]„, and organic products, S=§NRC6H4§-o, R=H, CH3 ). Oxidative addition of halogens to bis(thiazolyl) aurate complexes produced no isolable organometallic complexes. [AuC1 1]Li probably formed after repetitive oxidation addition (C1 2) and reductive elimination reaction (2-chlorothiazole). However, oxidation of these aurate complexes with SOC12 limited the reaction to one oxidative addition and one reductive elimination step to produce [AuCl(CNHYS)] (Y=CCH 3=CH, C6H4) after acidification. Reaction of the neutral mono(carbene) complex [Au(CNCCH 3=CHS)(C=NCCH3=CHS)] with C12, Br2 or 12 produced carbene complexes of gold(I), [AuX(6NHCCH 3=CH§)] (X=C1, Br, I), after reductive elimination of 2-halogeno-4-methylthiazole. Cationic bis(thiazolinylidene) complexes of gold(I) react readily with C1 2 and 12 to produce stable Ms(carbene) complexes of gold(III). However, oxidative addition on the same carbene complex by I2 is followed by a novel reductive elimination of (ICNii)cF SO to produce carbene complexes of gold(I), [AuI(CMN7- TTA )]. Alkylation (CF3SO3CH3) of 4-methylthiazole, bensothiazole and methylimidazole, followed by deprotonation (BuLi) produced free carbenes. These carbenes were trapped by reaction with [AuCl(tht)] to form carbene-chloro complexes of gold(I). Chloro(1,3- dimethylimidazolinylidene)gold(I) react readily with NaN 3 or AgNO3 to yield [AuX(CNCH3CH=CH1:TCH3)] (X = N3 or NO3 ). As part of this study the structures of several carbene complexes were determined, including five carbene complexes of gold(I) and one carbene complex of gold(III). Au-C bond lengths of between 1.92-2.13A were found with the largest Au-C separation in the carbene complex of gold(III), [Au(aNCH3CH=CHNCH3)2]CF3S03 . Certain complexes of gold(I) exhibit interesting Au...Au interactions (3.19-3.51A) resulting in the aggregation of gold atoms to form dimers and chains of gold(I) atoms. The structures of two related complexes of iron were also determined to investigate the effect of protonation on a neutral carbene precursor, [Fe(CO) 2Cp(C=CHCH=NNPh)], to form the cationic carbene complex, [Fe(C0) 2Cp(aCH=CHNHI:IPh)JCF3S03. Small changes in bond lengths and angles resulted upon carbene formation.

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

Pang Sik Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1979. / Bibliography: leaves 70-73. / Acknowledgement --- p.i / Abstract --- p.ii / Chapter Section I --- Introduction -- Annulenes, azaannulenes, bridged annulenes, and bridged azaannulenes --- p.1 / Chapter Section II --- Synthetic Plans --- p.19 / Chapter Section III --- Results and Discussions --- p.26 / Chapter Section IV --- Experimental --- p.51 / Bibliography --- p.70 / List of Spectra