Reversibelt syrebindande organometalliska komplex

Abstract

To porphyrins structurally related organometallic complexes, which bind oxygen reversibly, have been used in oxygen enriching processes either as actively oxygen binding groups in oxygen enriching membranes, or as mobile oxygen carriers in solution. The complexes of interest for this work are metalloporphyrins, -porphyrazines and -phthalocyanines. In the literature survey biological oxygen enriching systems are briefly discussed, as well as artificial systems where oxygen is enriched by mobile oxygen carriers or by oxygen enriching membranes. Metal complexes of porphyrins, porphyrazines and phthalocyanines are dealt with as potential oxygen carriers. Their synthesis, and especially their solubility and aggregation is discussed, since they are important properties to be tuned in order to maximize the oxygen transport capability in solution. The metallophthalocyanines were found to be the easiest to synthesize and the work is concentrated on them. The synthesis of metallophthalocyanines as well as methods for introducing substituents on them is reviewed in detail. Cobaltphthalocyanines have been found to be among the most suitable for oxygen transport, but the presence of the ferromagnetic Co(II) ion makes NMR analysis impossible. Therefore, the analysis and caracterization of phthalocyanines are discussed too. In the experimental part, the microwave assisted synthesis of a tetra-tert-butyl and a tetrafluoro substituted cobaltphthalocyanine is explored with two different methods, but with poor product quality. In the following experiments two water soluble cobalt-phthalocyanines are synthesized successfully, and they are characterized by IR, UV-Vis and mass spectroscopy. The analysis clearly indicates that the complexes dimerize in water, but exist as monomers in methanol solution. The water solubility is due to charged substituents: the first phthalocyanine is substituted with four by methylene quaternized pyridyloxy groups; the second phthalocyanine is substituted with four isophthalate phenoxy groups. The phthalocyanines were synthesized in refluxing pentanol with basic catalysis out of the corresponding phthalonitrile and metal salt. The phthalonitrile was formed by nucleophilic aromatic nitro replacement