A p-Sulfonatothiacalix[4]arene Supramolecular Capsule Containing a Dinuclear Copper(II) Complex

Abstract

The reaction of tetrasodium p-sulfonatothiacalix[4]arene (Na₄H₄TCAS), copper(II) nitrate and pyridine N-oxide (PNO) afforded a yellow copper(II)-p-sulfonatothiacalix[4]arene complex. X-ray diffraction analysis displays that it is an interesting dimeric supramolecular capsule, [Cu₂(PNO)₂(H₂O)₆]⁴⁺ ⊂ [(H₆TCAS)₂]^4 − ·22H₂O, in which two PNO molecules bridge the two Cu^II ions in the O,O′-μ₂ mode and the hydrophobic aromatic rings point into the cavities of the thiacalixarenes. Interestingly, the thiacalixarenes pack themselves into the closed pores through π…π interactions in ab plane, and these pores further link to each other through hydrogen bonding to construct infinite hydrophilic tunnels, which fill with the disordered water molecules as the guests.

In a dimeric supramolecular capsule, [Cu₂(PNO)₂ (H₂O)₆]⁴⁺ ⊂ [(H₆TCAS)₂]⁴·22H₂O, two PNO molecules bridge the two Cu^II ions in the O,O′-μ₂ mode and the hydrophobic aromatic rings point into the cavities of the thiacalixarenes. Interestingly, the thiacalixarenes pack themselves into the closed pores through π…π interactions in ab plane, and these pores further link to each other through hydrogen bonding to construct infinite hydrophilic tunnels, which fill with the disordered water molecules as the guests.

Keywords:

• p-Sulfonatothiacalix[4]arene
• Copper
• Supramolecular capsule
• Crystal structure

Acknowledgement

We thank the financial support from NSFC (No. 20231020), Natural Foundation of Fujian Province.