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.

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.

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.

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.

A series of geminal diethynylethenes (g-DEEs) with electron-donating and/or electron-accepting (D/A) groups were synthesized via a Pd-catalyzed cross-coupling sequence. The UV/VIS spectra for donor -acceptor (D -A) functionalized g-DEEs 5, 8, and 11 show distinctive absorption trends attributable to intramolecular charge-transfer (ICT). The bond-length-alternation (BLA) index for the cross-conjugated enediyne framework varies slightly with different terminal substituents as determined by density-functional theory (DFT) calculations and single-crystal X-ray analysis. Ultrafast third-order optical nonlinearities for the g-DEEs were measured by the differential optical Kerr effect (DOKE) technique and show that terminal donor -acceptor substitution of g-DEEs enhances molecular second hyperpolarizabilities (g) in comparison to donor or acceptor g-DEEs. A small increase in the twophoton-absorption cross-section (s (2) ) is observed in the series 9 -11 as a result of increased functionalization. The effects of donor/acceptor substitution on electron delocalization along the cross-conjugated enediyne structure are evaluated on the basis of natural-bond-orbital (NBO) analysis. Solid-state structures of the four derivatives 3b, 4b, 7 and 8 were characterized by single-crystal X-ray structural analysis and show an asymmetric unit cell for one derivative, D -A g-DEE 8.1. Introduction. -Conjugated molecules with highly delocalized and polarizable pelectron systems are prospects for third-order nonlinear optical (NLO) materials, and could form the basis for achieving ultrafast all-optical-based computing and telecommunications technology [1] [2]. To find ideal and applicable organic NLO materials, a large number of organic chromophores have been extensively explored, with many efforts focused on linearly conjugated aromatic and/or nonaromatic pconjugated systems [2 -5]. In assessing the suitability of an organic material for NLO purposes, its efficiency/transparency trade-off at a specific wavelength is an important factor to be considered, and maintaining transparency in the visible region of the spectrum is a significant challenge [6]. Many linearly p-conjugated chromophores tend to perform poorly in this respect, and the pursuit of alternative molecular designs has become more and more appealing and important. In particular, the use of cross-