Schiff Base Compounds The Synthesis Of New Nitrogen Support Tripod Structure And Its Coordination Properties

Tripodal ligands and their complexation are attracting considerable attention in the area of coordination chemistry. The attachment of three flexible donor-atom-containing chains to a framework leads to tripodal ligands, which can form stable complexes with many metal cations. These complexes can be widely used in coordination chemistry, electrochemistry, medicine, catalysis chemistry, biochemistry, supramolecular chemistry. For further investigation in this field, in this paper, we synthesized a series of new schiff base tripodal compounds and their transition mental ion complexes. All of the schiff base tripodals and their complexes were characterized by EA, IR, UV, ¹H NMR. The antibacterial activities of the schiff base tripodal compounds and complexes were also studied.1. Six kinds of new schiff base tripodals were prepared by using the triethanolamine, salicylaldehyde, and amines as materials. The synthesis of these compounds (3a-f) are shown as follows.The amines are as follows.Tris(2-chloroethyl)amine hydrochloride(1) was obtained by the reaction of triethanolamine with SOCl₂ at room tempreture. The preparation of the tris-aldehyde (2) was carried out by the reaction of tris(2-chloroethy)amine hydrochloride (1) with salicylaldehyde in the presence of anhydrous K2CO3 in N,N-dimethylformide. In the synthesis of (3a-f), the trialdehyde (2) was condensed with different amines in the solution of methanol or ethanol or dichloromethane-methanol mixed solvent.All of the tripod-like ligands are new compounds. The structures proposed for the new schiff base tripodal compounds are consistent with the data obtained from their EA, IR, UV, ¹H NMR spectra.2. Twenty-six complexes of the schiff base tripodals (3a-f) with transition metal cations (Cd²⁺, Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Fe³⁺) were prepared and characterized by EA, IR, UV spectra.By contrasting the IR spectra of the schiff base tripodal and their complexes, it is found that the vibration absorptions of C-O-Ar and C=N have obvious shifts. The UV spectra of the ligands and their transition metal complexes show that the maximal absorption wavelengths also have obvious shifts. These results denote that the oxygen and nitrogen atoms in the schiff base tripodals coordinate with the transition metal ions.3. The antibacterial activities of the schiff base tripodals and their complexes were determined. The study results show that most of the compounds have...