Synthesis, characterization and properties of new n-heterocyclic carbene complexes containing benzotriazole group

Among the members of the heterocyclic compounds family, imidazole and benzimidazole are the most known and most important members of this class of compounds. Benzimidazole and imidazole compounds are used as a carbon skeleton in the synthesis of carbene complexes and their numereous biological properties were reported. Alkylation or arylation of 1- and 3-position of benzimidazole and imidazole gives 1,3-substituted benzimidazolium or imidazolium salts. These salts are used as carbene source for the synthesis of carbene complexes. A wide variety of carbene complexes have been synthesized by dissociation of the hydrogen presents in the 2-position with the aid of a different base which coordinate to transition metals. The resulting metal-carbene complexes are used as catalysts in many reactions. In addition, many studies have been carried out on metal-carbene complexes in recent years to show antibacterial and anticancer properties. For all these reasons, metal-carbene complexes play an important role in organometallic chemistry. In this thesis, benzotriazol substituted benzimidazole and imidazole silver, palladium and ruthenium carbene complexes were synthesized. The structures of the new complexes were established by instrumental and spectroscopic methods. Anticancer activities of complexes have also been examined. The studies made within the scope of this thesis can be summerized under four titles; 1) The imidazolium and benzimidazolium salts (1a-f) containing the 1,2,3-benzotriazole group used as carbene precursors and silver complexes were synthesized by reaction with Ag2O to form (2a-f) Ag(I)-NHC complexes and their structures were elucidated by appropriate spectroscopic methods. Furthermore, the synthesized Ag(I)-NHC complex (2g) was synthesized by reacting AgNO3 with bis Ag(I)-NHC complex (2c) and its structure was elucidated by appropriate spectroscopic methods. 2) The Ru(II)-NHC complexes (3a-d) were synthesized by reaction of the synthesized Ag(I)-NHC complexes with [RuCl2(p-cymene)]2 and the structures were clarified by spectroscopic methods. 3) Pd(II)-NHC complexes (4a-d) were synthesized by reactionof imidazolium and benzimidazolium salts containing 1,2,3-triazole group as carbene precursors with PdCl2in the presence of base, and the structures were elucidated by spectroscopic methods. 4) The anticancer activities of Ag(I)-NHC, Ru(II)-NHC and Pd(II)-NHC complexes were investigated. Anticanceractivities of complexeswere determined by MTT cytotoxicity test against healthy mouse fibroblast cell line (L-929), human colorectal cancer cell line (Caco-2) and human breast cancer cell line (MFC-7). KEYWORDS: N-heterocycliccarbene, silver, ruthenium, palladium, anticancer, benzimidazole, imidazole, benzotriazole.