Synthesis and properties of carben complexes containing 4-hydroxyphenyl group

N-heterocyclic carbene (NHC) ligands have been of interest to organic and organometallic chemists for many years. NHC ligands; strong σ donor and weak π acceptor properties, the steric and electronic properties of the substituents on the nitrogen atom can be adjusted, stable and durable bonds with metals. Due to these properties, metal-NHC complexes synthesized using NHC ligands are used in many different fields. NHC ligands, which are used as catalysts in organometallic chemistry, have attracted much attention due to their biological activities and other medical applications. For the reasons stated above, the studies carried out within the scope of this thesis can be summarized under six headings: 1) In this thesis, 4-hydroxyphenyl substituted benzimidazolium salts 1a-g were synthesized as carbene precursor. Their structures were characterized by suitable spectroscopic methods. 2) All of the synthesized carbene precursors 1a-g were reacted with Ag2O in DCM to synthesize Ag(I)NHC complexes 2a-g. Their structures were characterized by appropriate spectroscopic methods. 3) NHC-Pd (II) 3-chloropyridine (Pd-PEPPSI) complexes 3a-g containing 4-hydroxyphenyl functional groups; carbene precursors were synthesized from the reaction of 1a-g and PdCl2 and their structures were characterized by appropriate spectroscopic methods. 4) Ru(II)NHC complexes 4a-e bearing 4-hydroxyphenyl functional groups were synthesized from the reaction of Ag(I)NHC complexes (2) and [RuCl2(p-cym)]2. Their structures were characterized by appropriate spectroscopic methods. 5) Enzyme inhibition activities in which 1,3-disubstituted benzimidazolium salts (1) and Ag(I)NHC complexes (2) bearing 4-hydroxyphenyl functional group were investigated. 6) Investigation of catalytic activity of direct arylation reactions of NHC-Pd(II)-3-chloropyridine complexes bearing 4-hydroxyphenyl functional groups. KEY WORDS: N-heterocyclic carbene precursors; Benzimidazole; Ag-NHC complexes; Ru-NHC; NHC-Pd (II) -pyridine (Pd-PEPPSI) complexes; DirectArilation; X-crystallography; Enzyme Inhibition.