Novel Metal−Organic Frameworks with Specific Topology Formed through Noncovalent Br···Br Interactions in the Solid State

Two coordination polymers [Ag(bib)]NO 3 ·H 2 O ( 1 ) and [Ag(bib)]ClO 4 ( 2 ) with one-dimensional (1D) chain structure were synthesized by reactions of ditopic ligand containing imidazole donors, namely, 1-bromo-3,5-bis(imidazol-1-ylmethyl)benzene (bib), with corresponding silver salts. While the bib ligand reacted with ditopic diacetato-zinc(II) acceptors, M 2 L 2 -type metallocyclic ring-like complex [Zn 2 (bib) 2 (OAc) 4 ]·2H 2 O (OAc = acetate anion) ( 3 ) was obtained, which was further connected by Br···Br interactions to lead to the formation of 1D pseudo-polyrotaxane. When ligand bib reacted with Zn(NO 3 ) 2 ·6H 2 O and Mn(NO 3 ) 2, two complexes [Zn(bib) 2 (H 2 O) 2 ](NO 3 ) 2 ·2H 2 O ( 4 ) and [Mn(bib) 2 (H 2 O) 2 ](NO 3 ) 2 ·2H 2 O ( 5 ) with 2D network structure were obtained in which the metal atoms had octahedral coordination geometry. The structures of these coordination complexes were determined by X-ray crystallography, and the results revealed that the coordination geometry of metal atoms have a great impact on the structure of the supramolecular architectures. Furthermore, the nitrate anions located in the voids between the 2D cationic layers in 4 can be exchanged by nitrite anions, which means that complex 4 with 2D network structure has anion exchange properties.