title: Formation of molecular ladder elements with macrocyclic platforms via linear bifunctional ligands.
abstract: Reaction between 4-aminopyridine and a dinuclear zinc(II) component of a Robson macrocyclic ligand has resulted in the formation of a molecular ladder element motif. X-ray single crystal structural analysis indicates that two pyridine rings are assembled at the same direction of the macrocycle, which are placed in a nearly parallel way via pi-pi interactions, forming a concavity structure with a macrocyclic base. It is significantly noted that one hydrogen-bond cycle generated from hydrogen atoms of two amino groups with two perchlorate anions has sustained such an assembly of two 4-aminopyridine species to stand in a face to face pattern through a weak molecular interaction on the macrocyclic platform by one-end coordination bonding. The self-assembly of 4-carboxylic pyridine acid and the same macrocyclic component in the presence of sodium hydroxide has yielded an interesting wheel-like complex. Two macrocyclic dinuclear zinc(II) components have been linked through coordination bonding with two pyridine derivatives situated on the same direction of a macrocycle. X-ray structural results suggest that the compound has a unique sandwich-like structure consisting of two macrocyclic covers with two inversely positioned bridging pyridine carboxylic groups in the middle.
authors.affiliation: State Key Laboratory, Coordination Chemistry Institute, Nanjing University, Nanjing 210093, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Shaohua
authors.initials: S
authors.lastname: Gou
authors.forename: Dahua
authors.initials: D
authors.lastname: Hu
authors.forename: Suchada
authors.initials: S
authors.lastname: Chantrapromma
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun
authors.forename: Qingjin
authors.initials: Q
authors.lastname: Meng