In Situ Tandem Synthesis of Charged Boron-Oxo Clusters into Highly Ordered Architectures

The controlled assembly of multiple cationic and anionic clusters into well-defined architectures remains one of the major challenges in chemistry. In this work, a series of charged boron-oxo cluster-based structures, named BOC-n (n = 1-8) have been successfully synthesized using an in situ tandem strategy. Through the comprehensive combination of the dynamic covalent chemistry and coordination interactions, porphyrin-like cationic metal boron-oxo clusters ([Cu(II)B₈O₈Qi₈]²⁺ in BOC-1 and [Cu(II)₂B₁₀O₁₂(Qi)₈]²⁺ in BOC-2 to 8; Qi = quinoline) have been developed. These cationic clusters further exhibit versatile dynamic properties and maintain directional control through metrically matched π─π stacking and C─H···π interactions during assembly, enabling the formation of highly ordered architectures with diverse incoming ligands and various guest anions. Notably, BOC-2 can reversibly respond to guest molecules through electrostatic interaction to facilitate anion exchange. Furthermore, the modulation of axial ligands and guest anions influence their optical third-order nonlinear properties.