A Calix-bis-crown with Hard and Soft Crown Cavities: Heterobinuclear +/Ag+ Complexation in Solid and Solution States

摘要

Calixcrowns offer particular utility since the fusion of calixarene and crown ether units enables the divergent orientation of cavities of a size and nature sufficient to accommodate a variety of guests.[1] Among them, calix[4]-bis-crowns[2] with a 1,3-alternate conformation (or saddle-type) have interesting features including 1) two crown cavities able to undergo dinucleation and 2) HSAB-based complexation selectivity.[ 3] Kim et al.[4] reported the synthesis of a heterodinuclear complex of an unsymmetrical calix-bis-crown with two different size crown loops: a crown-5 and a crown-6 suitable for K+ and Cs+, respectively. We recently reported the examples of calix[4]-bis-dithiacrown based, endo-coordinated disilver(I) complexes as well as an exo-coordinated 3D network connected by CuI-based clusters.[5]