Fine Tuning of the Cu(II)-Bis(imidazole) Networks by Changing Sulfonate Anions

In this paper, seven new compounds [Cu(biim-4) 2 (L1) 2 ] ( 1 ), [Cu(biim-4) 2 (L2) 2 ] ( 2 ), [Cu(biim-4) 2 (H 2 O)](L3) 2 ·H 2 O ( 3 ), [Cu(L4) 2 ](H 2 biim-4)·8H 2 O ( 4 ), [Cu(biim-4) 1.5 (H 2 O) 3 ](L5)·2H 2 O ( 5 ), [Cu(biim-6) 3 ](L1) 2 ( 6 ), and [Cu(biim-6) 3 ](L2) 2 ·H 2 O ( 7 ), where HL1 = 3-amino-4-methylbenzenesulfonic acid, HL2 = 2-amino-3,5-dimethylbenzenesulfonic acid, HL3 = 4-amino-2,5-dichlorobenzenesulfonic acid, H 2 L4 = 8-hydroxyquinoline-5-sulfonic acid, H 2 L5 = 1,5-naphthenedisulfonic acid, biim-4 = 1,1′-(1,4-butanediyl)bis(imidazole), and biim-6 = 1,1′-(1,6-hexanediyl)bis(imidazole), were successfully synthesized. The sulfonate anions of compounds 1, 2, and 4 coordinate to copper ions, while the sulfonates of 3 and 5 – 7 only act as counterions. In compounds 1 – 3, 6, and 7, copper ions are bridged by biim-4 or biim-6 ligands to form two-dimensional (2D) polymeric networks; in compound 5, copper ions are bridged by biim-4 ligands to form a one-dimensional (1D) ladder structure. In 4, [Cu(L4) 2 ] 2– anions, [H 2 biim-4] 2+ cations and lattice–water molecules are linked through hydrogen bonds and π−π interactions to give a three-dimensional (3D) supramolecular framework.