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Molecular structures and physicochemical properties of some chiral and helical transition metal complexes with polypyridines and tetradentate anionic ligands /Ho, Kwok-keung, Paul. January 1996 (has links)
Thesis (Ph. D.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 306-311).
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Studies on the synthesis of main group and late transition element frameworksSamanamu, Christian. January 2009 (has links) (PDF)
Thesis (Ph. D.)--Texas Christian University, 2009. / Title from dissertation title page (viewed June 2, 2009). Includes abstract. Includes bibliographical references.
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Synthetic and spectroscopic studies of metal carboxylate dimersTelser, Joshua A., January 1984 (has links)
Thesis (Ph. D.)--University of Florida, 1984. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 298-307).
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[Sigma]-bonded aryl-transition metal complexesStewart, Robert Perry, January 1970 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. Description based on print version record. Includes bibliographical references.
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Synthesis and reactivity of triangular phosphido-bridged transition metal clustersDehghan, Khashayar 19 June 2018 (has links)
The synthesis, reactivity, and spectroscopic properties of a series of triangular phosphido-bridged rhodium, iridium, palladium and platinum clusters are described. Throughout the project, X-ray diffraction and 31P{1H} NMR spectroscopy are the main techniques for characterizing compounds. In the first part of this report, the lability of μ-X and terminal phosphines in [M3(μ-X)(μ-PPh2)2(PPh3)3)[BF4](M= Pd, X= Cl; M=Pt, X= H) is utilized to prepare a number of compounds where the integrity of the triangular framework is maintained. The molecular structures of three representative examples: [Pd3(μ-SCH2Ph)(μ-PPh2)2(PEt3)3][BF4] [Pt3(μ-Cl)(μ-PPh2)2(PR3)3][BF4) (R= Ph, Et) were determined and are described. Reaction of these palladium and platinum trinuclear clusters with chelating ligands, R’2PYPR”2 (Y= O, CH2), results in unusual cluster fragmentation to give novel dinuclear monocations, [M2(μ-PP2)(μ-R’2PYPR”2) (PR3)2)+ (M= Pd, Pt) in which a metal-metal bond is supported by both dppm and phosphido bridges. These dimers are very inert failing to react with a number of reagents including C4H6, HCCCO2Me, CH2N2, CO, CH3I (when M= Pd), H2, HBF4 and CH2I2. The cluster, [Pt3(μ-H)(μ-PPh2)2(PPh3)3] [BF4], also reacts with ButNC to afford the dinuclear species (Pt2(μ-PPh2)2(ButNC)(PPh3)3]+. The crystal structures of fragmentation products [Pd2(μ-PPh2)( μ-Pri2PCH2PPh2)(PPh3)2] [BF4], (Pt2(μ-PPh2)( μ-Me2PCH2PMe2)(PPh3)2]2 [C2O4] and (Pt2(μ-PPh2)(ButNC)(PPh3)3]2(C2O4) are reported and discussed.
In the last part, the synthesis of a novel trinuclear iridium cluster, [Ir3(μ-PPh2)3(CO)5], is described, and the reactions of this cluster and its previously reported rhodium analogue, [Rh3(μ-PPh2)3(PPh3)2(CO)3], with dppm afford not fragmentation, but substitution products. The complex (Ir3(μ-PPh2)3(CO)5] also reacts with ButNC to yield [Ir3(μ-PPh2)3(CO)5(ButNC)2]. The crystal structures of the compounds, [M3(μ-PPh2)3(μ-dppm)(CO)3] (M= Rh, Ir) and (Ir3(μ-PPh2)3(CO)5(ButNC)2], are also reported. / Graduate
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Phosphinoalkylsilyl chemistry: tripodal and mesomolecular complexationGossage, Robert Arthur 13 July 2018 (has links)
The preparation of the modified silane [special characters omitted]; a phosphinoalkylsilane or PSi) via an alkylzirconium
intermediate is reported. The synthesis of [special characters omitted]
was carried
out by the reaction of organolithium reagents with chloro-silanes
at low temperature. The PSi compounds are isolated as
air-sensitive, thermally stable and very viscous liquids.
The reactivity of two of the silanes was investigated
with the platinum group metal complex [special characters omitted] (cod =
cycloocta-1,5-diene). In both cases, square planar platinum
(II) complexes were isolated. The reactivity of
[special characters omitted] produces five coordinate M (III)
complexes which undergo stereomutation. The isomerisation of
the syn to anti forms of [special characters omitted] has
been examined at several temperatures via NMR spectroscopy and
the activation parameters determined for the conversion of the
syn to the intermediate isomer form [special characters omitted]. The implications
of the stereomutation phenomona are discussed in relation to
catalysis. None of the isomers of this complex forms a stable
six coordinate adduct when reacted with a number of common
nucleophiles. The analogous compound where M = Ir and related
complexes of the formula [special characters omitted] are reactive towards CO to form stable six coordinate
adducts containing two M-P and one M-Si, M-H, M-CO and a M-Cl
bond. Some of these adducts can be made directly by the
reaction of the PSi ligand precursor with [special characters omitted] (M =
Rh, Ir) at room temperature. The reaction of the silane
[special characters omitted] produces
six coordinate complexes directly. For M = Ir, the compound
reacts with CO to produce a six coordinate cation by
displacement of a chloride ligand, the latter of which then
acts as a non-coordinating counterion.
A series of organosilicon dendrimers of the type :
[special characters omitted] ([G-1] : x
= 3, y = 2 = q = 0; [6-2] : y = 3, x = 9 , z = q = 0; [G-3] : z
= 3, y = 9, X = 27, q = 0; [G-4] : q = 3, z = 9, y = 27, x =
81) are sythesised and examined spectroscopically. All of the
dendrimers are air stable liquids. Species G3 has a marked
tendency to undergo what appears to be self-condensation
polymerisation. End and core group substitution is presented
for a carbosilane dendrimer containing one shell of identical
exterior Si atoms. The dendrimeric end groups can be modified
by the replacement of a terminal chloride by fluoride,
hydrogen, alkyl groups or metal complexes. The selective
removal of a core phenyl group can be accomplished with the
strong acid [special characters omitted]. The resulting silyl triflate can in turn
be used as a precusor to a silyl ether, hence facilitating selective core group modification. / Graduate
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Mononuclear and dinuclear complexes of rhodium and iridium: pyrazole complexes and pyrazolyl bridged dimersBailey, James Arthur 22 June 2018 (has links)
A series of mononuclear complexes of general formula
[M(η5-C5Me5)Cl3-n(pzH)n](n-1)+ (n = 1,2)
has been prepared as a result of an investigation of the reactivity of pyrazole with rhodium and iridium cyclopentadienyl and pentamethyl-cyclopentadienyl precursors. These complexes are discussed in terms of the dynamic processes that are exhibited in the 1H NMR experiment and in terms of their use as precursors to dimeric species. Dinuclear complexes of formula
[M(η5-C5R5)Cl(μ-pz)]2
containing pyrazolyl bridges have been prepared from the mononuclear compounds and from the chloro-bridged dimers of formula
[M(η5-C5R5)Cl2]2
by treatment with triethylamine, but not from the dipyrazole iridium cation
[Ir(η5-C5Me5)Cl(pzH)2]+ 26
which has been found to be unreactive to this type of symmetrical dimer formation: the low reactivity is attributed to a relative non-lability of the pyrazole groups. The dimeric complexes have been shown to undergo a core conformational change upon chemical reduction or halide abstraction. The chair conformation of the pyrazolyl bridged complex
[Rh(η5-C5ME5)Cl(μ-pz)]2 38
has been proven crystallographically. Chloride abstraction from 38 yields the binuclear product
[(Rh(η5-C5ME5)(μ-pz))2(μ-Cl)]BF4 46
which is bridged by two pyrazolyl and one chloride ligand and has been structurally characterized by X-ray diffraction to contain a boat conformation for the pyrazolyl framework. Reduction of either 38 or the
C5H5
analogue 40 results in the metal-metal bonded dinuclear complexes
[Rh(η5-C5ME5)(μ-pz)]2 48 and 49.
The C5H5
complex 49 has been crystallographically determined to possess the boat conformation. The reactivity of the metal-metal bonded products has been investigated: one and two fragment addition is discussed and a number of oxidative addition products have been structurally characterized. The mononuclear dipyrazole iridium cation 26 which contains non-labile pyrazole groups is utilized to prepare mixed-metal and mixed-oxidation state dimers with the formula
[Ir(η5-C5Me5)Cl(μ-pz)MLn].
The synthesis and potential for further investigation of these complexes is discussed. / Graduate
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Crystal structures and electrical resistivities of new YRu₄Sn₆-type rare-earth based compoundsKoch, Neil Erich 19 May 2009 (has links)
M.Sc. / Please refer to full text to view abstract
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Some problems in co-operative magnetismLindop, A. J. January 1966 (has links)
No description available.
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The spectra of complexes of conjugated ligandsSanders, Neil January 1968 (has links)
No description available.
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