Synthesis, Characterization and Crystal Structure of a New Schiff Base Ligand from a Bis(Thiazoline) Template and Hydrolytic Cleavage of the Imine Bond Induced by a Co(II) Cation  

作　　者：Jafar Attar Gharamaleki Fahimeh Akbari Akram Karbalaei Kamran B. Ghiassi Marilyn M. Olmstead Jafar Attar Gharamaleki;Fahimeh Akbari;Akram Karbalaei;Kamran B. Ghiassi;Marilyn M. Olmstead(Faculty of Chemistry, Kharazmi University, Tehran, Iran;Department of Chemistry, University of California, Davis, CA, USA)

机构地区：[1]Faculty of Chemistry, Kharazmi University, Tehran, Iran [2]Department of Chemistry, University of California, Davis, CA, USA

出　　处：《Open Journal of Inorganic Chemistry》2016年第1期76-88,共13页无机化学期刊（英文）

摘　　要：The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H₂L (1). Characterization of the ligand was performed by FT-IR, ¹H NMR, ¹³C NMR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The ligand, (1), possesses a disulfide –S–S– bridge of 2.1121 (3) ? length, and the molecule adopts a cis-conformation around this bond. In the crystal structure of (1), an intramolecular O–H···N hydrogen bond with D… A distance of 2.69 (3) ? was present. The reaction of (1) with Co(NO₃)₂·6H₂O and CuCl₂·2H₂O in methanol afforded the corresponding metal complexes. The obtained solids were further investigated by elemental analysis and UV-Vis titration that confirmed the formation of [CoL] and [ClCuHL] complexes. However, recrystallizaion of the Co(II) complex in dimethylsulfoxide caused the complete hydrolysis of the imine bond and afforded a Co(II) complex in which two 5-nitro-salicylaldehyde and two DMSO molecules were coordinated to the central metal in an octahedral fashion. This structure (2) was also confirmed by single crystal X-ray analysis.The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H₂L (1). Characterization of the ligand was performed by FT-IR, ¹H NMR, ¹³C NMR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The ligand, (1), possesses a disulfide –S–S– bridge of 2.1121 (3) ? length, and the molecule adopts a cis-conformation around this bond. In the crystal structure of (1), an intramolecular O–H···N hydrogen bond with D… A distance of 2.69 (3) ? was present. The reaction of (1) with Co(NO₃)₂·6H₂O and CuCl₂·2H₂O in methanol afforded the corresponding metal complexes. The obtained solids were further investigated by elemental analysis and UV-Vis titration that confirmed the formation of [CoL] and [ClCuHL] complexes. However, recrystallizaion of the Co(II) complex in dimethylsulfoxide caused the complete hydrolysis of the imine bond and afforded a Co(II) complex in which two 5-nitro-salicylaldehyde and two DMSO molecules were coordinated to the central metal in an octahedral fashion. This structure (2) was also confirmed by single crystal X-ray analysis.

关 键 词：Schiff Base Thiazoline Ligand Disulfide Bond Co(II) and Cu(II) Complexes Hydrolytic Cleavage Solution Study 

分 类 号：O62[理学—有机化学]