Second-order nonlinear optical hyperbranched polymers via facile ring-opening addition reaction of azetidine-2,4-dione

Synthesis, Structural Characterization and Biological Activity of Novel Cyclohexane-1,3-dione Ligands and Their Metal Complexes

Some new Zn(II) and Cu(II) complexes [Cu(L¹)(OAc)₂]∙H₂O, [Cu(L¹)(NO₃)H₂O]∙NO₃∙3.5H₂O, [Zn(L¹)(NO₃)₂]∙4.5H₂O, [Zn(L¹)(OAc)₂(H₂O)₂]∙3H₂O, [Cu₂(L²)(OAc)₄]∙2H₂O∙2DMF, [Cu(L²)₂]∙2NO₃∙1.5DMF∙H₂O, [Zn(L²)₂(NO₃)₂]∙DMF and [Zn₂(L²)(OAc)₄(H₂O)₄]∙5H₂O; L¹ = 2-[2-(2-methoxyphenyl)hydrazono]cyclohexane-1,3-dione and L² = 2-[2-(3-nitrophenyl)hydrazono]cyclohexane-1,3-dione were synthesized and characterized by IR, ¹H-NMR,¹³C-NMR and ultraviolet (UV-Vis.) spectroscopy, elemental analysis, magnetic susceptibility, mass spectrometry and thermogravimetry-differential thermal analysis (TGA-DTA). The synthesized ligands and their complexes were tested for antibacterial activity against Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, and Salmonella typhimurium CCM 583. Some of complexes showed medium-level antibacterial activity against the test bacteria compared with ampicillin.

Enhanced photovoltaic performance of inverted polymer solar cells by incorporating graphene nanosheet/AgNPs nanohybrids

A linear-dendritic block copolymer functionalized exfoliated graphene nanosheets/silver nanoparticles was prepared for using as the interfacial layer between the electron-selective layer and photoactive layer in an inverted polymer solar cell.

Functional hyperbranched polymers with advanced optical, electrical and magnetic properties

This review summarizes the recent progress in functional HBPs and their application in optics, electronics and magnetics, including light-emitting devices, aggregation-induced emission materials, nonlinear optical materials, chemosensors, solar cells, magnetic materials, etc., and provides outlooks for further exploration in the field.

Organic/Metallic nanohybrids based on amphiphilic dumbbell-shaped dendrimers

In this study, we synthesized a series of amphiphilic dumbbell-shaped dendrimers through the addition reactions of a hydrophilic poly(oxyalkylene) with hydrophobic dendrons based on 4-isocyanate-4'-(3,3-dimethyl-2,4-dioxo-azetidine)diphenylmethane with different numbers of branching generations. The addition reaction of azetidine-2,4-diones of dendrons to amines of poly(oxyalkylene) was proceeded by stirring the reactants in dry tetrahydrofuran (THF) under nitrogen at 60 °C. In aqueous media, the dumbbell-shaped dendrimers self-assembled into micelles with their hydrophobic dendrons in the core and their hydrophilic poly(oxyalkylene) segments forming loops in the corona shell. Employing the unique self-assembled micelle structures as templates for subsequent chemical reduction of the Ag(+) ions, we generated new types of organic/metallic [silver nanoparticle (AgNP)] nanohybrid clusters. The long poly(oxyalkylene) loops that extended into the aqueous phase complexed with the Ag(+) ions, providing the suspension with steric stabilization to prevent the AgNPs from collision and flocculation. After reduction, the AgNPs were present in a homogeneous distribution in the round dendrimer micelle-stabilized nanoclusters. The diameter of each AgNP was less than 10 nm; the diameter of each round nanocluster was in the range of 50-200 nm. The encapsulation efficiency of the AgNPs in micelles was about 54-69% for the dumbbell-shaped dendrimer based organic/AgNP nanohybrid.

Synthesis and nonlinear optical properties of a peripherally functionalized hyperbranched polymer by DR1 chromophores

The first peripheral postfunctionalization of a hyperbranched polyimide by nonlinear optic chromophores (DR1 derivative) was achieved using two different routes. The first one consists in the esterification of the terminal carboxylic acid groups, whereas the second is based on copper-catalyzed Huisgen reaction of the terminal propargylic ester groups. The resulting polymers display good solubility in classical organic solvents and good filmability because thick films can be prepared (up to 2.7 mum). The second-order nonlinear optical properties were measured by SHG at 1064 nm and we show that these hyperbranched polymers exhibit good poling efficiency and good thermal stability since the electro-optic activity remains stable up to 130 degrees C. These results illustrate the potential of hyperbranched polymers to host second-order nonlinear optical chromophores to replace dendrimers or classical linear polymers generally used in this area.