LAUSR

Abstract The mixed-ligand coordination polymers {[Zn(BIX) 2.5 ](NO 3 ) 2 ·5.5H 2 O} n ( 1 ), {[Co(BIX)(HBTC)](BIX) 0.5 ·H 2 O} n ( 4 ), [Ni(BIX) 2 (BDC)(H 2 O)] n ( 5 ), [Zn(BIX)(PDC)] n ( 6 ), [Ni(BIX)(PDC)(H 2 O)] n ( 7 ) and [Zn(BIX) 0.5 (HIDC)] n ( 8 ) were synthesized, structurally characterized and compared to the known coordination polymers {[Co(BIX) 3 ](NO 3 ) 2 ·4H 2 O} n ( 2 ) and {[Zn 2 (BIX)(BTC)(OH)]·H 2 O} n ( 3 ) to determine the mutual influence of an anionic carboxyl ligand and a neutral N-donor ligand (BIX = 1,4-bis((1H-imidazol-1-yl)methyl)-benzene; H 3 BTC = 1,2,3-benzene-tricarboxylic acid; H 2 BDC = 1,3-benzene-dicarboxylic acid (isophthalic acid); H 2 PDC = 3,4-pyridine-dicarboxylic acid; H 3 IDC = 4,5-imidazole-dicarboxylic acid). Compound 1 is a 1D ladder-like structure with two bridging and one terminal (dangling) BIX ligand. Neighboring ladders mutually entangle with the dangling BIX ligand being threaded through {Zn 4 (BIX) 4 } openings from adjacent strands. Compound 2 shows a 3D pcu -network with octahedrally coordinated cobalt ions bridged by three crystallographically different inversion-symmetric BIX ligands. The overall structure motifs in the mixed-ligand compounds are 1D metal-carboxylate chain-structures, bridged by neutral BIX ligands to form either 1D ladder-like strands ( 4 ), 2D networks ( 3 , 5 with square lattice, 4,4 or sql topology, 7 , 8 with honeycomb, 6,3 or hcb topology) or 3D frameworks ( 6 with diamond, 6,6 or dia topology). Noteworthy, compound 4 forms a 1D tubular structure of stacked {Co 2 (BIX) 2 } metallacycles that are threaded with uncoordinated BIX ligands like a rotaxane. A tetrahedral asymmetric Zn atom is formed in the crystals of 6 with spontaneous resolution as only one Zn configuration assembles into the 3D chiral framework of each single crystal.