A series of tetravalent zirconium and hafnium complexes were developed in their
abundant chemistry and photophysical properties, where those complexes were supported by
diarylamido-phosphino [iPr-PNP]- (bis(o-diisopropylphosphinophenyl)amide) ligand.
[iPr-PNP]MCl3 (M = Zr, Hf) were prepared by sequentially reacting [iPr-PNP]H with
n-butyllithium and following MCl4(THF)2 in toluene solution under ambient temperature.
UV-Vis absorption, emission, excitation spectrum, cyclic voltammetry experiments, and
density functionalization theory (DFT) calculations are applied to approach their unique
photophysical phosphorescence properties. Alkyls which are lack of £]-hydrogen have been
used to achieve in synthesis of degenerate ([iPr-PNP]MR3, R = Me, CH2SiMe3) or
non-degenerate ([iPr-PNP]M(E)(R)2, R = CH2SiMe3, E = Cl, Me) derivatives since we could
control the desired product from steric effect. Strong fluxional exchange was found in those
complexes. By variable temperature NMR monitoring and X-ray diffraction, their
fluxionality seems interesting not only in mechanism, but it does affect our reaction. By
heating [iPr-PNP]Zr(Cl)(CH2SiMe3)2 in solution, we can afford new alkylidene complexes
[iPr-PNP]M(Cl)(=CHSiMe3) via self £\-abstraction. Through variable temperature analysis,
the activation energy of £\-abstraction have £GH‡ = 18.5 kcal/mol and £GS‡ = -19.8 cal/mol¡PK.
Here we also can identified multiple alkylidene derivatives of [iPr-PNP]Zr(Me)(=CHSiMe3)2.
The computational studies of [MeNPiPr]Ni(R)(L) ([MeNPiPr]- = o-diisopropylphosphinoII
phenyl-2,6-dimethylanilite, R = Me, CH2SiMe3; L = 2,4-Lutidine, Py, PMe3) in C-H
activation has been fully established. Start on dissociation mechanism, we considered three
major pathways to explain the activation mechanisms including isomerisation, direct
intermolecular benzene activation, and intramolecular sp3 C-H acitvaition. Here we also
account H-D exchange as experimental observation. Important intermediates and transition
states are found to locate the energy maps to assist our experiments.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0818110-005338 |
| Date | 18 August 2010 |
| Creators | Hsiao, Yi-Chen |
| Contributors | Teng-Yuan Dong, Lan-Chang Lian, Ching-Han Hu |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0818110-005338 |
| Rights | not_available, Copyright information available at source archive |
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