Metalation of a Hierarchical Self-Assembly Consisting of π -Stacked Cubes through Single-Crystal-to-Single-Crystal Transformation.

Single-crystal-to-single-crystal metalation of organic ligands represents a novel method to prepare metal-organic complexes, but remains challenging. Herein, a hierarchical self-assembly {(H 12 L 8 )·([N(C 2 H 5 ) 4 ] + ) 3 ·(ClO 4 - ) 15 ·(H 2 O) 32 } ( 1 ) (L = tris(2-benzimidazolylmethyl) amine) consisting of π -stacked cubes which are assembled from eight partially protonated L ligands is obtained. By soaking the crystals of compound 1 in the aqueous solution of Co(SCN) 2 , the ligands coordinate with Co 2+ ions stoichiometrically and ClO 4 - exchange with SCN - via single-crystal-to-single-crystal transformation, leading to {([CoSCNL] + ) 8 ·([NC 8 H 20 ] + ) 3 ·(SCN) 11 ·(H 2 O) 13 } ( 2 ).