Ion Pair Binding in the Solid-State with Ditopic Crown Ether Uranyl Salophen Receptors.

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Crystal Engineering

Background:

• Uranyl salophen receptors are important in host-guest chemistry.
• Crown ether units are known for cation binding.
• Solid-state studies provide detailed structural insights.

Purpose of the Study:

• Synthesize ditopic uranyl salophen receptors with varying crown ether units.
• Investigate solid-state ion pair complexation with alkali and ammonium halides.
• Characterize the structural motifs and coordination polymers formed.

Main Methods:

• Synthesis of uranyl salophen receptors R(1) and R(2).
• Single-crystal X-ray diffraction analysis of 19 complexes.
• Analysis of ion pair interactions and structural motifs.

Main Results:

• Three general interaction motifs (I-III) were identified in solid-state structures.
• Motif I: separated ion pair; Motif II: polymeric structure; Motif III: stacked packing.
• The R(2)·NaI complex formed an infinite 1-D coordination polymer.
• The first solid-state structure of a uranyl salophen acetate complex was obtained.

Conclusions:

• Ditopic uranyl salophen receptors exhibit diverse solid-state complexation behaviors.
• Crown ether size influences the formation of polymeric structures.
• These findings contribute to the understanding of uranyl complex assembly and crystal engineering.