ABSTRACT
Two phenylboronic acid based saccharide sensors bearing conjugated oligomer fluorophores with linear and cruciform π-frameworks were synthesized in a modular approach utilizing a Cu-catalyzed alkyne azide cycloaddition (click) reaction. The cruciform fluorophore showed excellent saccharide sensing function under physiological conditions in the mM range, whereas the linear fluorophore gave very limited sensing functions. The different fluorescent sensing behaviours highlight the important role of oligomer fluorophore in the development of effective saccharide sensors.
Subject(s)
Boronic Acids/chemistry , Carbohydrates/chemistry , Fluorescent Dyes/chemical synthesis , Microscopy, Atomic Force , Models, Molecular , Molecular StructureABSTRACT
A series of linear and star-shaped pi-conjugated oligomer hybrids (2-5) composed of an oligoyne core, ranging from 1,3-butadiyne to 1,3,5,7,9,11-dodecahexayne, and fullerenyl end-capping groups has been synthesized and studied. The molecular structures of these fullerene-oligoyne hybrids were assembled through three key reactions: Pd-catalyzed cross-coupling, Cu-catalyzed oxidative homocoupling, and an in situ alkynylation reaction on [60]fullerene. The properties of these compounds were investigated by UV-vis spectroscopy, differential scanning calorimetry (DSC), and atomic force microscopy (AFM) with the purpose of understanding the thermal reactivity arising from the oligoyne moieties as well as the morphological properties on surface. Our study shows that these fullerene-oligoyne hybrids tend to aggregate in different morphologies, including nanospheres, nanoflakes, and continuous thin films, while the morphological properties appear to be subject to the influence of molecular factors such as oligomer chain length, solubilizing alkylphenyl groups, and the thermal reactivity of the oligoyne unit. The correlation between molecular property and interfacial aggregation behavior evinced by these fullerene-oligoyne hybrids suggests a viable approach to exert bottom-up control over the structures and properties of fullerene based nanomaterials.
ABSTRACT
A new class of two-dimensional (2D), pi-conjugated, skewed H-shaped co-oligomers of phenylene vinylene and phenylene ethynylene (11a- d, termed H-mers) were synthesized using Sonogashira coupling and Wittig-Horner reactions as the key steps. Electronic and spectroscopic properties of the H-mers were investigated by UV-vis absorption, fluorescence spectroscopic techniques, and ab initio calculations (HF/3-21G). Two amino-containing functional H-mers (11b and 11d) were found to exhibit appealing fluorescence sensitivity to selected Brønsted acids and transition-metal ions.
ABSTRACT
Suitably modified linear conjugated poly(arylene ethynylene)s are able to assist effective debundling and dispersion of crude as-prepared single-walled carbon nanotube powders in organic solvents, the dispersion of which is effected via a surface coating mechanism and, to some extent, in a size-selective fashion.
Subject(s)
Nanotubes, Carbon/chemistry , Polymers/chemistry , Molecular Structure , Particle Size , Powders/chemistry , Surface PropertiesABSTRACT
A 1,3,5,7-octatetrayne-linked bis(fullerene) compound has been synthesized. Through a thermally induced solid-state polymerization reaction on a surface, the solid thin film of this compound was transformed into a highly uniform and well organized polymer nanosphere array. This finding suggests a simple and useful method for the preparation of carbon-rich, fullerene-containing nanoparticles.
