Apart from their general usage as tanning agents for hides and skins, the natural tannins have been used since earliest times for various other purposes. The blue-black iron tannate complex was used by ancient Egyptians as a hairdye and for many conturies this complex was the main source of writing inks. Wattle tannin is known to form complexes with many metal ions. The chief use of tannin complexes has been in gravimetric analyses, since aqueous solutions of tannins readily precipitate metal ions under certain experimentel conditions. At the present time the nature of the precipitated complexes has not been investigated however, because in the gravimetric method the complexes are ignited and the metal determined as its oxide; hence no knowledge of the complexes themselves was required.

A series of chelating amino siloxide and alkoxide ligands have been prepared. Barium, lanthanide and zirconium complexes bearing these new ligands have been synthesized and characterized by NMR or X-ray crystallography. Reactivity of the zirconium complexes has been studied. The tris(siloxide) lanthanide(III) complexes are all monomeric in both solution and solid-state. A yttrium tris(siloxide) and a zwitterionic ytterbium tetrakis(siloxide) complexes have been characterized by X-ray crystallography. The yttrium complexes have shown high volatility. Mono(siloxide) barium(II) silamide complexes are dimeric as determined by X-ray crystallography, and barium bis(siloxide) exists as a monomer-dimer equilibrium in hydrocarbon solvents. Although highly soluble in hydrocarbon solvents, the barium complexes are non-volatile. A new aryl(siloxide) ligand has been synthesized and used as an ancillary ligand for the preparation of lanthanide dialkyl complexes. Although ligand redistribution was not observed, “ate”-complexes were isolated instead of neutral dialkyl complexes. Zirconium bis(aminodiolate) complexes were synthesized by reaction of tetrabenzyl zirconium and two equivalents of the ligands. The substituents on nitrogen were found to have a great effect on the structure. Mono(aminodiolate) zirconium dialkyl complexes were successfully synthesized by three different methods: protonolysis, ligand redistribution and metathesis. Thermal decomposition of these zirconium dialkyl complexes was found to show a marked dependence on the substituents at nitrogen. The α-methyl benzyl derivative decomposed by ortho-metallation of phenyl group exclusively and resulted in clean formation of a metallacyclic complex. The reaction of primary amines with the metallacycle allowed isolation of amide intermediates protonolysis of the benzyl group, and eventually resulted in formation of bridging imide complexes. The insertion reaction of carbonyl groups (C=O) into the metallacycle Zr-carbon bond proceeds regio- and stereoselectively. The first insertion products of carbonyl insertion were isolated, and the β-naphthaldehyde insertion product was characterized by X-ray crystallography. The metallacycle exhibited catalytic activity towards alkyne cyclotrimerization without preactivation. Zirconium cationic complexes were generated by alkyl abstraction using [special characters omitted]. The cationic complexes generated from the zirconium dibenzyl derivatives showed catalytic activity towards both ethylene and 1-hexene polymerization. A new cyclopentadienyl ligand bearing pendant fluorinated alkoxide functionality was synthesized. The zirconium complexes bearing this ligand exhibited remarkably high Lewis acidity, and the dichloride complex was shown to be catalytically active towards vinylether polymerization. / Graduate

At the beginning, a brief overview of two-dimensional materials as well as an introduction of the organic metal complex nanosheets was presented in chapter 1. In this section, the attention was mainly focused on the concept of the 2D nanomaterial, including the design strategies, the categories, the synthetic approaches and the characterization methods. Also, the materials used as electrodes of batteries for energy storage were generally introduced. Those electroactive materials were classified according to their different functional mechanism. The opportunity and challenge of this kind of electroactive materials were then demonstrated. At last, the current development of the 2D materials as electrodes, including the typical structures and the superiority, was indicated.;A brand-new symmetric four-way terpyridine derivative (1,2,4,5-tetrakis(4-(2,2':6',2"-terpyridyl)phenyl)benzene) (L7) was then designed and coordinated with Co(II) ion to assemble a novel bottom-up multilayer nanosheet 7-Co in chapter 4. The generated nanosheet featured moderate mechanical strength and insolubility in both aqueous solution and organic solvent, which can facilitate the purification and collection of the product. By taking the advantages of the reversible and robust redox activity of Co2+/Co3+, a dual-ion battery cathode was achieved by employing the 7-Co and thus it reveals the possibility of this kind of metal organic complex nanosheet to be utilized in a battery.;1.7\xFinally, the findings, analysis results and future work were concluded in chapter 6. And the experimental details were described in chapter 7

No description available.

published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

Chapter 1 provides the general review of phosphoranoimines and 1-azaallyls as ligands for group 4 and 14 metal complexes. / Chapter 2 describes the development of low-valent group 14 1,3-dimetallacyclobutanes from phosphoranoimines. Three low-valent 1,3-distannacyclobutanes 1,3-[Sn{C(Pr i2P=NSiMe3)(2-Py)}]2 ( 95), 1,3-[Sn{C(Ph2P=NSiMe3)(C6H 5)}]2 (97) and 1,3-[Sn{C(Ph2P=NSiMe 3)(PPh2)}]2 (100) were synthesized from the phosphoranoimine ligands [CH2(Pri 2P=NSiMe3)(2-Py)] (92), [CH2(Ph 2P=NSiMe3)(C6H5)] (96) and [CH2(Ph2P=NSiMe3)(PPh 2)] (99), respectively. A novel cationic tin(IV) species [HC(Pri2P=NSiMe3)(Ar)] -[SnCl3]+ (Ar = 9-anthryl) ( 104) was synthesized from [CH2(Pri 2P=NSiMe3)(Ar)] (Ar = 9-anthryl) (103). / Chapter 3 describes the reactivies of low-valent group 14 1,3-distannacyclobutanes (95 and 111) and the isolation of the enantiomers of 95 and [1-Sn{C(Pri2P=NSiMe 3)(2-Py)}3-Pb{C(Pri2P=NSiMe 3)(2-Py)}] (120). The reactions of 95 or 111 with M(CO)5(THF) (M = Cr, Mo, W), CpMn(CO)2THF (Cp = eta-C5H5), MeI and Br2 were performed. Three isomers of compound 95 (95R, 95S and 95I) and two enantiomers of compounds 120 ( 120R and 120S) and 122 (122R and 122S) were obtained by the method of recrystallization from different solvents. Heteroleptic lead(II) compound [{(Pri 2P=NSiMe3)(2-Py)CH}Pb{N(SiMe3)2} 2] (121) was synthesized, which further react with 94 to give 1,3-[Pb{C(Pri2P=NSiMe 3)(2-Py)}]2 (122). / Chapter 4 describes the development of group 4 metal complexes from phosphoranoimines. Group 4 metal imido complexes [(Me2N)2M{CH(Ph2 PN)(2-Py)}]2 (M = Zr (133), Hf (134)) and ionic compounds [ML2Cl]+2[MCl 6]2- (L = {CH(R2PNSiMe3)(2-Py)}) (135 M = Zr, R = Ph, 136 M = Hf, R = Ph, 137 M = Zr, R = Pri, 138 M = Hf, R = Pri) were synthesized. The neutral zirconium(IV) dichloride compound [ZrCl2{CH(Ph2P=NSiMe 3)(C6H5)}2] (139) was prepared by the reaction of lithium compound [(THF)2Li{CH(Ph 2PNSiMe3)(C6H5)}] (97) with ZrCl4. The catalytic activity of the compounds toward ethylene polymerization has been investigated. / Chapter 5 describes the development of group 4 metal complexes from 1-azaallyls. Lithium cyclohexenyl-1-azaallyl compound [(TMEDA)LiN(SiMe3)C(Ph)= CHCHC&parl0;SiMe3&parr0;CH2CH 2C H2] (149) and zirconium(IV) dichloride compound [Zr{N(SiMe3)C(Ph)(L)}2Cl2] (L = CHCHC&parl0;SiMe3&parr0;CH2CH 2C H2) (150) were synthesized. Novel anionic one-dimensional bifunctional lithium compound [{(THF)Li(N(SiMe3))2C}(CN)C 6H4-1,4)]n (151) has also been synthesized. Similar reactions of 1,2-dicyanobenzene, 1,3-dicyanobenzene or 1,4-dicyanobenzene with lithium amide [(Et2O)2LiN(SiMe3) 2] afforded lithium bis(1,3-diazaallyl) compounds [{(THF)2Li(N(SiMe 3))2C}C6H4-1,2)] (152), [{(THF)2Li(N(SiMe3))2C}C6H 4-1,3)] (153) and [{(THF)2Li(N(SiMe3)) 2C}C6H4-1,4)] (154), respectively. / The work presented in this thesis is mainly focused in two parts: (i) the synthesis and reactivities of low-valent main group 14 metal complexes derived from phosphoranoimines, (ii) the synthesis and catalytic studies of transition group 4 metal complexes derived from phosphoranoimines and 1-azaallyl ligands. / Wong Kam Wing. / "December 2006." / Adviser: Kevin Wing-Por Leung. / Source: Dissertation Abstracts International, Volume: 68-08, Section: B, page: 5233. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

published_or_final_version / Chemistry / Master / Master of Philosophy

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

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 137-147).