固態結構與自組裝反應的實驗結果一致,證明此系列的配位子在與銀形成錯合物時,可自組裝形成穩定的錯合物。 In this research, a series of new ligands (L1、L2、L3、L4 and L5) containing hydrazone and derivative pyridine moiety were synthesized. Four silver complexes, [Ag2L22](BF4)2 (1)、{[Ag4L32(H2O)2](BF4)4‧2H2O}∞ (2)、[Ag3L52]2(PF6)5 (3)、[Ag2L52](PF6)2 (4) have been prepared and characterized by X-ray diffraction study.
Complex 1 synthesis from L2 and silver salt, the oxygen atoms were bridge two silver ions. Complex 2 can further form coordination polymer. According to different synthesis, L5 can form Ag3L52 and Ag2L52 complexes. The Ag-Ag distance smaller than the sum of Van der Waals radii of silver ion. The π−π stacking interaction to form polymeric superstructure.
Compare with NMR titration of L5 and NMR of complex 3, we found that even if the formation of complex 3 is Ag3L52, complex 3 need more silvers to stabilize the structure in solution state, and we found that the structure of complex 2 and 3 will distorted by using the VTNMR studys.
The self-assembling process and reaction mechanism were studied by UV-Vis titration. The step-wise and overall ability constant of L、AgL、AgL2、AgL2、Ag4L2 were investigated by systematic measurement.
The results were consistent for the crystal and titration of L2 with AgPF6. Overall, double helical structure is the most stable conformation of L2 silver complex.