Abdelkrim El-ghayoury

Preferential hetero-dimer formation and equilibrium dynamics of self-complementary bifunctional oligo(p-phenylenevinylene) and C60 ureido-pyrimidinone derivatives in solution

The formation of hetero-dimers of bifunctional oligo(p-phenylenevinylene) and C60 ureido-pyrimidinone derivatives has been observed by 1H-NMR and fluorescence techniques.

Metallo-supramolecular oligo(p-phenylene vinylene)/[60]fullerene architectures: towards functional materials

The assembly of p-conjugated woligo(p-phenylene vinylene)x OPV donors and w60xfullerene acceptor moieties into a supramolecular donor-acceptor system is achieved by ruthenium complexation. The synthesis and optical properties of a novel photoactive supramolecular dyad and triad are described to access the photoinduced formation of a charge-separated state. 2002 Elsevier Science B.V. All rights reserved.

Synthesis of liquid crystalline oligo(p-phenylene vinylene)

The synthesis of oligo(p-phenylene vinylene) with mesogenic side chains is described, with the objective to explore highly ordered n-conjugated materials for functional properties. In the case of dimeric and tetrameric (p-phenylene vinylene) only a melt transition was observed while in the case of hexameric (p-phenylene vinylene) a liquid crystalline phase was found under the polarization microscope.

Quadruple hydrogen bonded oligo(p-phenylene vinylene) dimers

Direct self-assembly of π-conjugated oligomers via nself-complementary quadruple hydrogen bonding is achieved and the first nsteps towards supramolecular polymers with functional side chains are ndescribed.

Supramolecular fullerene architectures by quadruple hydrogen bonding

The synthesis and full characterization of a quadruple bonded fullerene dimer using self-complementary 2-ureido-4[1H]pyrimidinone units with high dimerization constants is described. The chemical integrity of the monomeric moiety in either compound is fully preserved, also with respect to its redox and UV-Vis behavior. Two novel supramolecular dyads consisting of an oligo(p-phenylene vinylene) (OPV) donor and fullerene (C-60) acceptor are created via quadruple hydrogen bonding upon mixing the fullerene dimer and an OPV dimer. In these supramolecular dyads, singlet-energy transfer from the excited OPV unit to the fullerene causes a strong quenching of the OPV fluorescence. The high association constant of the 2-ureido-4[1H]-pyrimidinone quadruple hydrogen-bonding unit results in high quenching factors (Q(max) greater than or equal to 90). The lower limit obtained for the rate constant for energy transfer (k(EN) greater than or equal to 6 x 10(10) s(-1)) is rationalized in terms of the Forster mechanism.

Dual‐cure processes: towards deformable crosslinked coatings

Two dual-cure processes consisting of a UV-initiated radical polymerization followed by either a UV-induced cationic polymerisation, or a thermal addition reaction, were investigated. The feasibility of the processes was studied using an acrylate-oxetane monomer for the UV/UV combination, and an acrylated oligoester for the UV/Heat combination. It was shown by FTIR and Tg measurements, that both steps of each process could be performed efficiently and separately. This allowed the production of a deformable partially cured coating, whose cure can then be completed, leading to the required final properties. Furthermore, it was demonstrated that the increase of the functionality of the reactive diluent led to a decrease of the thermal crosslinking extent. This is probably due to the reduced mobility of the reactive species that is caused by an enhanced UV crosslinking taking place during the first step.

Combination of supramolecular cross-linking with covalent cross-linking through epoxide ring-opening including gel studies

Abstract Terpolymers based on poly(methyl methacrylate), containing terpyridinemoieties as well as epoxide groups, were synthesized via free-radical polymerization. The products were cross-linked non-covalently with iron(II) ions and covalently by treatment with AlCl3. Both steps could be combined in different order. The non-covalent cross-linking could be reversed by applying a strong competing ligand. The swelling behaviour of the polymers was investigated.