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## Alkylzinc derivatives of guanidines – synthesis, research and reactivity

### Michał Leszczyński

#### Abstract

Introduction Reactivity of the alkylzinc compounds in the oxidation process has been a subject of research for decades. Such an interest is kept at a high level according to numerous practical applications of the zinc compounds such as nanocrystalline zinc production, asymmetric catalysis or catalysts for polymerization of heterocyclic monomers and olefins. Investigation of reactivity of the alkylzinc compounds towards oxygenation and hydrolysis appears to be particularly interesting research topic as it leads to the synthesis of new zinc materials of a substantial application potential. The aim of his work is the synthesis and investigation of the alkylzinc complexes with a bicyclic guanidine ligand – hpp- and the examination of it’s reactivity towards molecular oxygen and water by means of the molecular characterization of the intermediate species and the final products obtained in reactions of these complexes. Results and discussion The reactivity of the complex [EtZn(hpp)]3 towards water and molecular oxygen was examined by conducting reactions under various conditions with an intention to isolate and analyze obtained products. As a result, two novel zinc complexes were characterized: [EtOZn(hpp)2ZnCl]2 with chloride substituents produced by the activation of the solvent molecules (Scheme 1) and [(EtZn)4(μ4 O)4Zn6(hpp)8] – incorporating an unique [Zn10O4]12+ core adapting the shpalerite-type ZnO structure. Scheme 1. Synthesis of [EtOZn(hpp)2ZnCl]2 using [EtZn(hpp)]3 as substrate In the next stage of research the new trimeric t-buthylzinc compound [t-BuZn(hpp)]3 was synthesized and utilized to examine the reactivity of oxygen and water towards it, resulting in an isolation of two different crystalline forms of the same oxozinc product [(t-BuZn)3(μ4 O)Zn(hpp)3] and [(t-BuZn)3(μ4 O)Zn(hpp)3] · 2 THF, with the only difference being presence of solvent molecules in the crystal structure (Scheme 2). Further attempts of complete reaction of all alkyl groups in substrate [t-BuZn(hpp)]3 allowed for the isolation and examination of complex [Zn(O-hpp)2]2 · 2 t-BuOH incorporating a novel oxidized bicyclic guanidine system. Scheme 2. Synthesis of [t-BuZn(hpp)]3 and it’s further transformation into [(t-BuZn)3(μ4 O)Zn(hpp)3] Conclusions Six novel zinc clusters illustrating different stages of reactions of substrate complexes [EtZn(hpp)]3 and [t-BuZn(hpp)]3 with oxygen and water were obtained. Results presented in this thesis are characterized by both high cognitive as well as practical value. Optimization of presented reaction conditions may contribute to the design of advanced synthetic method for nanocrystalline zinc oxide precursors or to the synthesis of novel organometallic compounds suitable for catalysis or other fields of research.
Record ID
WUTa9bfcc961bbc408abf00642755b02420
Diploma type
Master of Science
Author
Michał Leszczyński Michał Leszczyński,, Undefined Affiliation
Title in Polish
Alkilocynkowe pochodne guanidyny – synteza, badania i reaktywność
Supervisor
Karolina Zelga (FC/DCOC) Karolina Zelga,, Department Of Catalysis And Organometallic Chemistry (FC/DCOC)Faculty of Chemistry (FC)
Certifying unit
Faculty of Chemistry (FC)
Affiliation unit
Department Of Catalysis And Organometallic Chemistry (FC/DCOC)
Study subject / specialization
, Technologia Chemiczna
Language
(pl) Polish
Status
Finished
Defense Date
25-09-2012
Issue date (year)
2012
Keywords in Polish
-
Keywords in English
-
Abstract in Polish
urn:pw-repo:WUTa9bfcc961bbc408abf00642755b02420