by Shan-Ming Kuang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (p. 135-152). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

The first two chapters of this thesis are devoted to exploring the reactivity of electron rich molybdenum and tungsten trimethylphosphine complexes with hydrosilanes. These complexes, Mo(PMe3)6 and W(PMe3)4(n2-CH2PMe2)H, have been shown to be highly reactive species that undergo a number of bond cleavage reactions. In the presence of the hydrosilanes PhxSiH4-x (x = 0 - 4), Mo(PMe3)6 and W(PMe3)4(n2-CH2PMe2)H effect Si-H and Si-C bond cleavage, along with Si-Si bond formation; however, the products derived from these reactions are drastically different for Mo(PMe3)6 and W(PMe3)4(n2-CH2PMe2)H and are highly dependent on the substitution of the silane. Mo(PMe3)6 reacts with SiH4, PhSiH3, and Ph2SiH2 to afford novel silyl, hypervalent silyl, silane, and disilane complexes, as respectively illustrated by Mo(PMe3)4H2(SiH3)2, Mo(PMe3)4H(k2-H2-H2SiPh2H), Mo(PMe3)3H4(s-HSiHPh2), and Mo(PMe3)3H2(k2-H2-H2Si2Ph4). Mo(PMe3)4H(k2-H2-H2SiPh2H) is the first example of a complex with a hypervalent [H2SiPh2H] ligand, and Mo(PMe3)3H2(k2-H2-H2Si2Ph4) represents the first structurally characterized disilane complex. In addition to being structurally unique, these complexes also possess interesting reactivity. For example, Mo(PMe3)4(SiH3)2H2 undergoes isotope exchange with SiD4, and NMR spectroscopic analysis of the SiHxD4-x isotopologues released indicates that the reaction occurs via a sigma bond metathesis pathway. In contrast, W(PMe3)4(n2-CH2PMe2)H affords a range of products that includes metallacycle, disilyl, silane, and bridging silylene complexes. The disilyl compounds, W(PMe3)4H3(SiH2SiHPh2) and W(PMe3)3H4(SiH2Ph)(SiH2SiHPh2), exhibit the ability of W(PMe3)4(n2-CH2PMe2)H to cause both redistribution and Si-Si bond formation. A mechanism involving silylene intermediates is proposed for the generation of these complexes, and this mechanism is supported computationally. Additional support for the presence of intermediates comes from the isolation of a unique complex with a bridging silylene ligand, "WSiW". The bridging silylene bonding motif is unprecedented. The reactivity of the simplest hydrosilane, SiH4, was also examined with IrCl(CO)(PPh3)2 (i.e. Vaska's compound). Previous reports on this reaction have assigned the product as trans-IrH(SiH3)(Cl)(CO)(PPh3)2, in which the hydride and silyl ligands are mutually trans. It is noteworthy, therefore, that we have now obtained a crystal structure of the product of this reaction in which the hydride and silyl ligands are cis, namely cis-IrH(SiH3)(Cl)(CO)(PPh3)2. Calculated energies of the isomeric species also suggest that the product of this reaction was originally misassigned. These results, and the analogous reactions with germane (GeH4), are described in Chapter 4. Chapter 4 also discusses some reactions of transition metal phosphine complexes, including Ru(PMe3)4H2, Mo(PMe3)6, W(PMe3)4(n2-CH2PMe2)H, and Mo(PMe3)4(n2-CH2PMe2)H, with industrially relevant substrates. Ru(PMe3)4H2 effects the water gas shift reaction of CO and H2O to form CO2 and H2. Furthermore, Ru(PMe3)4H2 reacts with CO2, CS2, and H2S to respectively form formate, thiocarbonate, and hydrosulfido complexes. The reactivity of Mo(PMe3)6 and W(PMe3)4(n2-CH2PMe2)H towards molecules relevant to the hydrodeoxygenation industry, including dihydrofuran and benzofuran, was studied. The products of these reactions exhibit hydrogenation of unsaturated bonds and C-O bond cleavage, both of which are essential to the hydrodeoxygenation process. Mo(PMe3)4(n2-CH2PMe2)H reacts with PhI to form an alkylidyne species, [Mo(PMe3)4(CPMe2Ph)I]I, which was structurally characterized by X-ray diffraction. W(PMe3)4(n2-CH2PMe2)H forms a k2-adduct when treated with 2-seleno-2-methylbenzimidazole, namely W(PMe3)4(sebenzimMe)H. Chapter 3 discusses the development of two new ruthenaboratrane complexes, [k4-B(mimBut)3]Ru(CO)(PR3) (R = Ph, Me). The structures of these complexes are described, and their d6 metal configuration is supported by both Fenske-Hall and Natural Bond Orbital calculations. Some reactivity of these complexes was also explored. For example, [k4-B(mimBut)3]Ru(CO)(PMe3) appears to add MeI across the Ru-B bond. Finally, as an extension of the work that we have done on tungsten trimethylphosphine complexes, the structure of W(PMe3)3H6 in solution was investigated, and the results are presented in Chapter 5. T1 measurements of the hydride ligands and deuterium isotope effect shifts both confirm that this complex exists as a classical hydride in solution, which is in accord with the classical hydride formulation in the solid state that was previously determined by X-ray diffraction.

Chapter 1 gives a brief introduction to metal complexes supported by anionic nitrogen-based ligands. / Chapter 2 describes the synthesis, structural characterization and reactivity of Mn(II), Fe(II) and Co(II) amides derived from the strongly electron-withdrawing [N(C6F5)(C6H3Pr i2-2,6)]- ligand (L 1). Twelve new compounds, including the ligand precursor HL 1, and three alkali-metal and eight late transition metal derivatives of L1, were prepared. Reactions of MCl2 (M = Mn, Fe, Co) with [Li(L1)(TMEDA)] (2) yielded the monoamido complexes [M(L1)Cl(TMEDA)] [M = Mn (5), Fe ( 6), Co (7)]. Treatment of [Li(L1)(THF) 3] with MCl2 (M = Fe, Co) afforded the diamido complexes [M(L1)2(mu-Cl)Li(THF)3] [M = Fe ( 8), Co(9)]. The reaction chemistry of the Co(II) complex 7 was investigated. Treatment of the Co(II) derivative 7 with LiMe, NaN3 and NaOMe gave the corresponding methyl-, azido- and methoxide-amide complexes, namely [Co(L1)(Me)(TMEDA)] ( 10), [Co(L1)(N3)(TMEDA)] (11) and [Co(L1)2(mu-OMe)Na(TMEDA)] (12), respectively. The solid-state structures of complexes 5--12 were determined by X-ray crystallography. / Chapter 3 reports on the synthesis and catalytic properties of lanthanide(III) complexes derived from the unsymmetrical [PhC(NSiMe3)(NC6 H3Pri2-2,6)] - ligand (L2). The lithium and potassium salts of L2, and eight lanthanide(III) derivatives of L2 were synthesized. A series of Ln(III) complexes of the general formula [Ln(L 2)2(mu-Cl)2Li(TMEDA)] [Ln = Y (17), Eu (18), Er (19), Lu (20)] and [Li(THF) 4][Ln(L2)2Cl2] [Ln = Ce ( 21), Nd (22), Sm (23)] were synthesized by the reactions of anhydrous LnCl3 with two molar equivalents of [Li(L2)(TMEDA)] (15). In addition, the neutral dimeric yttrium(III) complex [Y(L2)2(mu-Cl)] 2 (24) was also prepared by the reaction of anhydrous YCl 3 with the potassium amidinate [K(L2)]n (16). The catalytic properties of complexes 20--22 towards the ring-opening polymerization of epsilon-caprolactone were also studied in this work. / Chapter 4 reports on the coordination chemistry of L2 towards divalent lanthanide metal ions. Three neutral divalent lanthanide complexes, [Ln(L2)2(THF)n] [Ln = Sm, n = 2 (25); Ln = Eu, n = 2, (26); Ln = Yb, n = 1 (27)], were prepared by treatment of LnI2(THF) 2 with the potassium amidinate [K(L2)]n . The reaction chemistry of 25--27 as one-electron transfer reagents has been examined. This led to the isolation of six lanthanide(III) complexes (28--33). Treatment of 25--27 with PhEEPh (E = Se, Te) gave the corresponding Ln(III) chalcogenolate complexes [Ln(L2)2(mu-EPh)]2 [Ln = Sm, E = Se (28); Ln = Eu, E = Se (29); Ln = Sm, E = Te ( 31)] and [Yb(L2)2(SePh)(THF)] (30). Besides, the reaction of 27 with iodine resulted in the isolation of the iodide complex [Yb(L2)2(I)(THF)] ( 32), whilst treatment of 25 with dicyclohexylcarbodiimide led to [Sm(L2)2{CyNC(H)NCy}] (33). / Chapter 5 summarizes the results of this research work. A brief suggestion on future directions of this research project is also discussed. / The present research work was focused on the coordination chemistry of the highly electron-withdrawing [N(C6F5)(C6H 3Pri2-2,6)]- ligand and the unsymmetrical [PhC(NSiMe3)(NC6H 3Pri2-2,6)- ligand. The first part of this work was centered on the synthesis, structure and reactivity of late transition metal complexes supported by the [N(C6F5)(C6H3Pr i2-2,6)]- ligand (L 1). The second part of this work dealed with the chemistry of trivalent and divalent lanthanide complexes derived from the bulky [PhC(NSiMe3 )(NC6H3Pri 2-2,6)]- ligand (L2). / Yao, Shuang. / Adviser: Hung Kay Lee. / Source: Dissertation Abstracts International, Volume: 71-01, Section: B, page: 0317. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

2-Pyridinyl-2-pyrazinylmethanone (L4) is able to exist in the neat ketone form and gem-diol form (2-C5H4N)C(OH) 2(2-C4H3N2) (L4a) in its Ag(I) and Cu(II) complexes. Two isostructural Cu(II) complexes [Cu(L4 a)2X2·2H2O, X = C lO4-, BF4-] with the L4a ligand taking the chelating mode are formed, in which the different linkage modes of lattice water molecules between the Cu(L4 a)22+ units lead to different space groups in crystallization. Through versatile anion-pi(pyrazinyl ring) and hydrogen-bonding interactions, the Cu(L4a)22+ units are assembled into distinct 3-D metal-organic hybrid frameworks in these two complexes. Different ligation modes of L4 in its neat ketone and gem-diol forms are found in its silver(I) complexes that exhibit diverse network structures. / By tuning the counter anion, mu2-bridging 2,6-pyridinediylbis(4-pyridinyl)methanone (L2) via two terminal 4-pyridyl N atoms links Ag(I) ions into two distinct structural motifs in its silver(I) complexes, namely infinite helical chain and metallacyclophane, which are further assembled into higher-dimensional metal-organic frameworks through Ag···Ag, pi···pi, hydrogen-bonding, Ag···O=C, carbonyl···carbonyl, as well as unconventional anion-pi(pyridyl ring) interactions. Intermolecular dipolar carbonyl···carbonyl interaction of three principal types serves as a common dominant non-covalent interaction in the supramolecular conglomeration of these complexes. / Di-2-pyrazinylmethanone (L3) readily undergoes metal-assisted hydration reaction in its Ag(I), Cu(II), Co(II) and Cd(II) complexes, and is potentially useful for the construction of extended coordination networks with its gem-diol (2-C4H3N2)2C(OH) 2 (L3a) or anionic (2-C4H3N 2)2C(OH)CO- (L3b) form as an architectural moiety. A sheet-like net, an alpha-polonium topology of the NaCl-type and a rare 1-D nanotubular coordination architecture has been generated in its Ag(I) complexes through the tuning of counter-anions. Three isostructural complexes Cu(L3a)2X2· nH2O (n = 4.5; X = ClO 4-, BF4-, PF 6-) have been obtained and characterized. The 3-D host frameworks of these complexes are constructed from the linkage of mononuclear Cu(L3a)22+ metallotectons through a combination of hydrogen-bonding and anion-pi interactions, leading to honeycomb-like channels that accommodate guest water molecules. A cubane-like Co(II) cluster stabilized by L3b and the topological structure of Cd(II) complexes with L3a have also been obtained. / Di-2-pyridinylmethanone (di-2-pyridyl ketone) is a well-known versatile ligand among the basic building blocks for the construction of metal-organic hybrid materials. It can exist in its neat form, or in the hydrated gem-diol and alcoholated hemiketal forms. In this thesis, through modification of the heterocyclic ring and the bridging functional group, we have systematically synthesized a series of transition metal complexes of five carbonyl-bridged heterocycles (L1-L5) (see P. xi) and two structural analogs with sulfinyl and sulfonyl bridging groups (L6-L7), which are expected to provide flexible coordination bonding and additional non-covalent interactions in the generation of metal-organic hybrid frameworks. / In the two mononuclear Cu(II) complexes of 2,6-pyridinediylbis(3-pyridinyl)methanone (L1) with the ligand taking a chelating mode, four distinct types of unconventional intermolecular C=O···pi interactions between the carbonyl and pyridyl rings were identified. Moreover, the mu2-bridging L1 via two 3-pyridyl N atoms proves to be an excellent building block for the construction of disilver(I) metallacyclophanes with a [Ag2(L1) 2]2+ skeleton in a series silver(I) complexes. The [Ag 2(L1)2]2+ metallacycle functions as a secondary building unit to form infinite chains through Ag···O=C or argentophilic interactions, which are further assembled into a 3-D supramolecular structure via collective weak interactions including the anion-pi interaction. The employment of different Cd(II) and Hg(II) salts to react with the flexible L1 ligand has resulted in infinite chain, mononuclear, and 3-D network structures, in which L1 takes eta1-terminal, N,N-chelating, and mu2- and mu3-bridging modes. In these complexes, C--H···O, C--H···Cl--M hydrogen bonding, pi···pi, carbonyl···carbonyl, O(perchlorate)···C=O, as well as unconventional anion···pi(pyridyl ring) interactions, play important roles in consolidation of the supramolecular frameworks. / Sulfinyldipyrazine (L7) is capable of forming intriguing architectures in various sivler(I) salts, including a series of coordination polymers exhibiting (4,4) net, infinite chain and 3-D framework structures. A remarkable characteristic of L7 is that the electron-deficient pyrazinyl ring and the sulfonyl group provide potential bonding sites for lone-pair-aromatic interactions in the supramolecular assemblies, such as anion-pi and S=O···pi(pyrazinyl ring) interactions. The S=O moiety of the sulfonyl group exhibits an affinity for the pyrazinyl ring, which is evidenced by the existence of two types of such interaction in the silver(I) complexes of L7. (Abstract shortened by UMI.) / by Wan, Chongqing. / Adviser: Thomas C. W. Mak. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3504. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 172-190). / 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.

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.

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"September 2002" Includes as appendix: a list of publications by the author arising from this work; and, copies of some published journal articles Includes bibliographical references. Describes the synthesis, properties and reactions of transition metal complexes containing poly-ynyl ligands

"September 2002" / Includes as appendix: a list of publications by the author arising from this work; and, copies of some published journal articles / Includes bibliographical references. / [12], 209 leaves, [35] pages : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Describes the synthesis, properties and reactions of transition metal complexes containing poly-ynyl ligands / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemistry, 2002

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 194-202).