Capped Nanojars: Synthesis, Solution and Solid-State Characterization, and Atmospheric CO₂ Sequestration by Selective...

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Nanojars are supramolecular coordination complexes that encapsulate anions, typically formed using strong bases.
• The self-assembly of nanojars is sensitive to reaction conditions, including the base used.

Purpose of the Study:

• To investigate the formation of novel nanojar structures using weak bases instead of strong bases.
• To characterize the resulting capped nanojars and understand their properties and reactivity.
• To explore the potential of these capped nanojars for selective gas capture and anion binding.

Main Methods:

• Synthesis of capped nanojars using trialkylamines (weak bases) and copper(II) ions with pyrazole.
• Characterization via electrospray ionization mass spectrometry, UV-vis, NMR spectroscopy, X-ray diffraction, and elemental analysis.
• Investigation of acid-base reactivity and selective CO2 capture experiments.

Main Results:

• Successful synthesis of capped nanojars with a distinct [Cu3(μ3-OH)(μ-pz)3L3]2+ cap, differing from conventional nanojars.
• Capped nanojars selectively sequester CO2 from air, converting it to carbonate, with selective binding over other anions.
• Capped nanojars identified as crucial intermediates in the pH-controlled assembly-disassembly of nanojars.

Conclusions:

• Replacing strong bases with weak bases leads to the formation of novel capped nanojars.
• Capped nanojars exhibit selective CO2 capture and conversion capabilities, demonstrating potential for carbon capture applications.
• The study elucidates the role of capped nanojars as intermediates in nanojar supramolecular chemistry.