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The thesis deals with Pd(II) catalysts, bearing anionic phosphine/ sulfonate ligands (PSO), with the intention of making non-alternating E/ CO-copolymers accessible. Starting from the Pd precursor [(dcp)PdCl]2, SCCs (single component catalyst), with a variable substitution pattern in the phosphine moiety and their influence on the polymeric products are described. The structures of the dimeric complexes and (PSO)Pd(dcp) catalysts are proved. Experiments clearly show, that according to DFT calculations, the ligand, bearing the bulkiest substituent in ortho-position (-isopropoxy) yielded the highest amount of extra-ethylene in the copolymer. The highest amount (36 % on top) was obtained, when CO was added at a slave factor of 5. The same PSO catalysts also show the ability of copolymerizing C2H4 and acrylates. In chapter 3, nickel complexes of the PSO ligands were tested as C2H4 polymerization catalysts. (PSO)Ni(Ph)(PPh3) complexes are synthesized, which gave a highly active system for ethylene polymerizations. Without applying any scavengers, the catalyst produced reasonable amounts of polymer. By increasing the sterical bulk of the ligand (-isopropoxy) and the electronic influence on the metal ion, the equilibrium of coordinated and free triphenylphosphine is shifted to the latter, causing a significant raise in the activity. In chapter 4 a deprotonated phosphonic acid group is supposed to coordinate to the metal center. Thus, phosphine/ phosphonate and phosphine/ phosphinate ligands with a variety of substitution patterns are synthesized. X-ray analysis of the complexes revealed a chelated coordination mode of the PPO ligands to be true. The complexes developed in this chapter do up to now not show any catalytical activity in preliminary polymerization experiments. However, it is proved in this chapter, that these ligands do not only coordinate via their phosphorus atom as stated in the literature before, but act as chelating ligands.

Sol-gel derived organic-inorganic hybrid materials with potential fields of application as refractive optical components for example laser diode bars and ophthalmic lenses are presented. The main components of the hybrid materials under investigation are precondensed methacryloxypropyltrimethoxysilane (MPTS, denoted: M) with an organically polymerisable methacrylic functionality and tetraethyleneglycoldimethacrylate (TEGDMA, denoted: T) as crosslinking organic monomer with two polymerisable double bonds. The molar ratios of the components ranged from M/T 10/90 up to M/T 70/30. The polymer derived from pure TEGDMA (M/T 0/100) served as a reference material. In addition to this nanoscaled TiO2 particles (5 wt.% and 10 wt.%) were incorporated in the organic-inorganic M/T 30/70 matrix to increase the refractive index of the resulting nanocomposites. For the preparation of the different systems, precondensed MPTS was mixed with TEGDMA, the nanoparticulate titania sol (when used), an appropriate photoinitiator and a thermoinitiator. The reaction mixtures were polymerised photochemically and/or thermally. The propagation of the free radical polymerisation reaction after photopolymerisation and subsequent thermal curing was followed by IR-spectroscopy, showing that the degree of double bond conversion is strongly increased by the thermal curing step. Incorporation of increasing amounts of TiO2 nanoparticles resulted in reduction of the double bond conversion compared to the corresponding unfilled system. The homogeneous dispersion of the titania particles in the completely cured M/T 30/70 matrix could be manifested by high resolution transmission electron microscopy (HTEM). The thermomechanical properties of the completely cured nanocomposites were monitored by dynamic mechanical thermal analysis (DMTA) showing a strong dependence on composition.

Hydrolysis and condensation of alkoxides involve different reaction steps. Generally the first step is the dissolution of monomers in organic solvents like alcohols. The second step is hydrolysis, where in most cases condensation may not be separated. Dissolution may incorporate solvatation, coordination, complexation of polymerization. The addition of water leads to hydrolysis of Si-O-C bonds and subsequently condensation of silanoles takes place. Another possibility of reaction is the hydrolysis-free condensation. As a functionof reaction conditions and starting material different possibilities and mechanisms may take place. General conclusions are hardly to be drawn, since the comparison of data is difficult. In the paper theoretical models are reviewed and compared with experimental data. Conclusions with respect to the formation of solid materials are drawn.