Synthesis and characterization of some novel lariat-type ligands as [ONS] donors of diamide crown compounds

Lariat-type ligands are a specialized class of macrocyclic ligands distinguished by the presence of one or more pendant arms or tail-like extensions attached to the macrocyclic core. These pendant arms typically contain donor atoms such as nitrogen, oxygen, or sulfur, which participate in metal coordination. The unique structural features of lariat-type ligands enable them to modulate the coordination environment and binding affinity toward metal ions. This study primarily focuses on the synthesis of novel lariat-type ligands that function as [ONS] donors for diamide crown compounds. The experimental procedure involved conversion of ۲,۴-dimethylphenol (۲,۴-DMP) into a bisphenol compound. Transformation of the bisphenol into a methyl diester derivative through reaction with methyl chloroacetate. Reaction of the methyl diester with a suitable diamine, triethylenetetramine, to produce the corresponding diamide macrocycle. Modification of the diamide macrocycle to obtain the lariat structure by reaction with various monofunctional agents, such as ditosylate, ۴-chlorophenol, hexanoyl chloride, and formaldehyde. Finally, The structures of all synthesized compounds were thoroughly characterized and confirmed using a combination of spectroscopic techniques, including ۱HNMR, ۱۳CNMR, MS(mass spectrometry), and FT-IR spectroscopy. The reaction efficiency of lariat ۴ and lariat ۵ were ۵۵% and ۹۶% respectively. Also, the melting point of lariat ۴ and lariat ۵ ۱۷۱-۱۷۴ °C and ۱۵۳-۱۵۵ °C respectively.

کلیدواژه ها:

Macrocycle ، Lariat ، Diamide crown compound ، ۱HNMR ، ۱۳CNMR ، MS ، FT-IR