Unique Deca‐ and Tetranuclear Halocuprate(I) Clusters of a Clamplike Ligand: Isolation, Structure, and Luminescence Properties

The reaction of 3‐aminopyridine with formaldehyde afforded a clamplike ligand, 3,7‐di(3‐pyridyl)‐1,5‐dioxa‐3,7‐diazacyclooctane (L). The diffusion of a CH 2 Cl 2 solution of L into an MeCN solution of CuX produced one decanuclear cluster [Cu 10 Cl 10 (L) 4 ] ( 1 ) and two tetranuclear clusters [Cu 4 X 4 (L) 2 (MeCN) 2 ] [X = Br ( 2 ), I ( 3 )]. Compound 1 possesses a unique [Cu 10 Cl 10 ] cluster core consisting of two stairlike [Cu 5 Cl 5 ] fragments that share two μ 6 ‐Cl and two μ‐Cl atoms. Compounds 2 and 3 have a stairlike [Cu 4 X 4 ] cluster core that is anchored by two L ligands. The trans configuration of the two pyridyl groups of the free L ligand was converted into the cis configuration of the two pyridyl groups of each bridging L ligand in 1 – 3 . The photoluminescence properties of 1 – 3 in the solid state were also investigated.