Influence of anions and mole ratio on the formation of 2-D coordination networks of thiacalix[4]-bis-monothiacrown-5

Abstract

Anion and mole-ratio effects on the formation of coordination polymers (1–3) of thiacalix[4]-bis-monothiacrown-5 (L) incorporating two types of sulfur donors (crown loop and rim) are reported. In the reaction with AgPF₆, an anion-uncoordinated two dimensional (2-D) coordination polymer {[Ag₂L₃](PF₆)₂}_n (1) adopting a honeycomb (hcb) topology was isolated as a mole-ratio independent product. In the reactions with AgCF₃CO₂, an anion-coordinated honeycomb type 2-D coordination polymer {[Ag₂L₃(CF₃CO₂)₂]·6CHCl₃·2H₂O}_n (2) and a square-grid type 2-D coordination polymer {[Ag₄L₃(CF₃CO₂)₄]·0.5CHCl₃·0.5CH₃OH·0.5toluene}_n (3) with an sql topology were obtained below 1.0 equiv. and above 1.3 equiv., respectively. All products demonstrate that the only sulfur donor in the crown loop acts as a versatile bridgehead for the exo-binding probably due to its stronger basicity than that of the sulfur bridge in the rim. The powder X-ray diffraction (PXRD) studies reveal that anion-exchange between 1 (PF₆, hcb) and 3 (CF₃CO₂, sql) in the solid state is reversible.