Synthesis, Characterization, And Properties Of Organometallic Complexes With Heterocyclic Ligands

Organometallic complexes are in a wide range of application in medicine, pesticides, and industrial areas as one of the important forefront academic areas. In this paper, synthesis, characterization and luminescent properties of heterocycle-based Schiff base and their metal complexes were investigated; functionalized ionic liquids were synthesized and characterized; and pyridine organic intermediates were prepared:(1) Three 5-substituted 3-methoxy-salicylaldehyde (substituents were in terms of 2-furyl, 3-pyridyl, and 2-N-methylimidazolyl) and two 3, 5-disubstituted salicylaldehyde (substituents were in terms of 2-pyridyl and 2-thienyl) were synthesized, respectively. The condensation between each of the first three salicylaldehyde and o-phenylenediamine or ethylenediamine led to five Schiff base compounds at a high yield (80 97%). Then the Schiff base compounds form five complexes with transition metal ions Zn³⁺ (3d) at a higher yield (88 97 %). Finally, zinc-lanthanide bimetallic Schiff base complexes were formed from the five zinc complexes, and the lanthanide metals were assigned to Nd³⁺, Gd³⁺, Tb³⁺, Er³⁺, Yb³⁺, respectively.These complexes were characterized by NMR, IR, MS. The photophysical properties of those complexes were examined. The results show that all the Schiff base ligands can excitate the lanthanide ions Nd³⁺, Er³⁺, Yb³⁺ to luminescent at near-infrared regions (NIR). The luminescent mechanism of those bimetallic complexes was confirmed by examining the photophysical properties of Gd³⁺ complexes.(2) Three phosphine complexes such as 1,1'-bis[3-(diphenylphosphino)propyl]-2,2'-biimidazole, 1,1'-bis[3-(diphenylphosphono)propyl]-2,2'-biimidazole, 1,1'-bis[3-(diphenylphosphothino)propyl]-2,2'-biimidazole were synthesized from 1,1'-di[3-(hydroxypropyl)]-2,2'-biimidazole and 1,1'-di(3-Chloropropyl)- 2,2'-biimidazole. And functionalized ionic liquids were synthesized from 1,1'-bis[3-(diphenylphosphino)propyl]-2,2'-biimidazole. The complexes were characterized by NMR, IR, MS.(4) Two important organic intermediates 2-pyridylborates such as 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine and 2-(1,3,6,2-trioxaborocan-2-yl)pyridine were prepared. The synthesis programs were researched, and ionic liquids were employed to afford a green and efficient scheme. The products were characterized by GC-MS.