Influence of anions and mole ratio on the formation of 2-D coordination networks of thiacalix[4]-<i>bis</i>-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)]center dot 6CHCl(3)center dot 2H(2)O}(n) (2) and a square-grid type 2-D coordination polymer {[Ag4L3(CF3CO2)(4)]center dot 0.5CHCl(3)center dot 0.5CH(3)OH center dot 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.