ABSTRACT
The formation of metallo-cages is affected by a variety of factors such as the ligands, metals, and anions, among which the impact of metals with different binding capacities is particularly important, but has rarely been studied in three-dimensional metallo-cages. Herein, we report the design of truxene-centered terpyridine ligands and the self-assembly of a series of tetrameric metallo-cages. The utilization of metal ions with strong (Zn2+, Fe2+) or weak (Cd2+) binding strength afforded 3D metallo-cages with low symmetry or highly symmetric metallo-tetrahedra, respectively, possessing totally different geometrical configurations. In addition, their photophysical properties and host-guest chemical properties were investigated.
ABSTRACT
The construction of low-symmetry topological supramolecular structures using bistable building blocks remains challenging. We report an unusual truncated triangular prismatic cage with D3h symmetry using a ligand with both cis- and trans-configurations upon coordination with metal. This work provides new ideas and methods for the future synthesis of low-symmetry topological supramolecules.
ABSTRACT
The precise control over hierarchical self-assembly of superstructures relying on the elaboration of multiple noncovalent interactions between basic building blocks is both elusive and highly desirable. We herein report a terpyridine-based metallo-cage T with a tetrahedral motif and utilized it as an efficient building block for the controlled hierarchical self-assembly of superstructures in response to different halide ions. Initially, the hierarchical superstructure of metallo-cage T adopted a hexagonal close-packed structure. By adding Cl- /Br- or I- , drastically different hierarchical superstructures with highly-tight hexagonal packing or graphite-like packing arrangements, respectively, have been achieved. These unusual halide-ion-triggered hierarchical structural changes resulted in quite distinct intermolecular channels, which provided new insights into the mechanism of three-dimensional supramolecular aggregation and crystal growth based on macromolecular construction. In addition, the chiral induction of the metallo-cage T can be realized with the addition of chiral anions, which stereoselectively generated either PPPP- or MMMM-type enantiomers.
ABSTRACT
OBJECTIVE: To inquire into the relationship between lipoprotein lipase (LPL) gene D9N, N291S and S447X polymorphisms and the development of cardiovascular diseases in children with obesity. METHODS: The polymerase chain reaction (PCR) and restriction fragment length polymorphism (RLFP) techniques were used to detect three common mutations of LPL gene exon D9N, N291S and S447X in 157 obese children and 175 normal controls. Plasma lipid and lipoprotein levels between children with different genotypes were compared. RESULTS: The D9N and N291S gene mutations were not detected in either the obese or the control groups. There were no significant differences in the frequency of S447X gene mutation between the two groups. There were no significant differences in the levels of plasma lipid and lipoprotein between children with S447 and X447 genotypes. CONCLUSIONS: D9N and N291S gene mutations may not be risk factors associated with cardiovascular diseases in children with obesity. S447X gene mutation might not play an important role in the development of cardiovascular diseases in childhood.
