Synthesis, Structure, and Functionalization of Homo Heterocalix[2]arene[2]triazines: Versatile Conformation and Cavity Structures Regulated by the Bridging Elements
作者:Yin Chen、De-Xian Wang、Zhi-Tang Huang、Mei-Xiang Wang
DOI:10.1021/jo100571c
日期:2010.6.4
Homo[4] heterocalix[2]arene[2]triazines yielded more diverse conformational structures including partial cone, pinched partial cone, 1,2-alternate and twisted 1,2-alternate, depending on the nature of bridging moieties. On the basis of 1H NMR spectra, homo[2] and homo[4] heterocalix[2]arene[2]triazines were fluxional macrocycles in solution, and they underwent rapid conformation interconversion at different
renewed interest as MRI contrast agents due to safety concerns related to the use of Gd(III)-chelates. While the preparation of oligomeric and polymeric Gd(III)-chelates is widely employed to multiply their efficiency, scarce examples of this strategy are reported for the corresponding Mn(II)-complexes. Two novel ditopic DO3A-based ligands were designed and synthesized and their Mn(II)-complexes evaluated