Polymerizing Cluster Helicates into High‐Connectivity Networks

Solvothermal reactions of Cu II salts and 3,5‐bis(4‐pyridyl)pyrazole (H L ) under various conditions gave three different types of crystalline compound, namely [Cu 2 (Cu 5 L 6 )]BF 4 ⋅ 5 H 2 O ( 1 a ), [Cu 2 (Cu 5 L 6 )]ClO 4 ⋅ 5 H 2 O ( 1 b ), and [Cu 7 (CN) 2 (Cu 5 L 6 ) 2 ][BF 4 ] 3 ( 2 ). 1 a and b were obtained in ethanol and NH 3 ⋅ H 2 O, whereas 2 was obtained in methanol and NH 3 ⋅ H 2 O. The three complexes were constructed by incorporating new pentanuclear copper(I) pyrazolate bis(triple helical) cluster helicates (Cu 5 L 6 ) as the second building units (SBUs), in which as many as twelve 4‐pyridyl N atoms are available for further coordination and construction of high‐connectivity topological networks. In 1 a and b , seven 4‐pyridyl N atoms are linked to three three‐coordinated Cu I atoms and four four‐coordinated Cu I atoms, which results in 3,4,7‐connected networks. In 2 , as many as eleven 4‐pyridyl N atoms coordinate to eleven Cu I atoms, which results in a 4,10‐connected topological network. The increasing connectivity of the cluster nodes in 2 is closely related to the in situ‐formed CN − anion bridge around the periphery of the pentanuclear cluster helicates. The luminescenct properties of these compounds were also investigated.