Interaction of metal salts with polyethers

The dielectric properties of pure low to medium molecular weight poly(ethylene glycol) and poly(propylene glycol) and a variety of their salt complexes have been studied through the measurement of the dielectric permittivity and dielectric loss over a range of frequency and temperature. The major proportion of this study has been concerned with the examination of the nature of the interaction between mercuric chloride and poly(propylene glycol) (PPG). Other salt-poly-ether combinations have also been considered such as cobalt chloride-PPG cadmium chloride-PPG zinc chloride-PPG and ferric chloride-PEG (polyethylene glycol). Some of this work was also supported by chemical shift and spin-lattice Nuclear Magnetic Resonance (N.M.R.) spectroscopy. The dielectric permittivity data were analysed using the Onsager relation to calculate the mean dipole moment per dipolar unit. This approach was employed in the discussion of various models proposed for the structure of salt-polyether complexes. The effect of mercuric chloride on the statistical conformations of poly(propylene-glycol) was studied in a quantitative manner using the relationships of marchal-Benoit. The dielectric relaxation activation energy and mean energy difference between gauche and trans conformations of poly(propylene glycol) in the presence of mercuric chloride, both showed a distinct minimum when the concentration of mercuric chloride was close to 5 mole %. Opposite behaviour was observed for the Cole-Cole parameter. It was concluded that the majority of the dielectric data could be rationalised in terms of a 5-membered cyclic complex formed between mercuric chloride and PPG in which the complexed segment of the polyether-(OMeCH2CH2O)- adopted either gauche or cis conformations.

Facile synthesis of poly(3-hexylthiophene)-block-poly(ethylene oxide) copolymers via Steglich esterification

Poly(ethylene oxide) has been coupled to poly(3-hexylthiophene) using esterification to produce pure diblock copolymers, highly relevant for use in organic electronic devices. The new synthetic route described herein uses a metal-free coupling step, for the first time, to afford well-defined polymers in high yields following facile purification.

Photoluminescent materials based on PMMA and a highly-emissive octahedral molybdenum metal cluster complex

Materials that combine photoluminescence, optical transparency and facile processability are of high importance in many applications. This article reports on the development of photoluminescent poly(methyl methacrylate) materials based on novel highly emissive anionic molybdenum cluster complex [{Mo6I8}(OTs)6]2– (where OTs– is the p-toluenesulfonate ion). The materials were obtained by both solution and bulk copolymerisation of methyl methacrylate and (dMDAEMA)2[{Mo6I8}(OTs)6], where dMDAEMA+ is the polymerisable cation [2-(methacryloyloxy)ethyl]dimethyl-dodecylammonium. Evaluation of the resultant hybrid materials showed that one could combine the excellent photoluminescent properties of the cluster complex with the transparency and processability of PMMA.

Photoluminescent materials based on PMMA and a highly-emissive octahedral molybdenum metal cluster complex

Materials that combine photoluminescence, optical transparency and facile processability are of high importance in many applications. This article reports on the development of photoluminescent poly(methyl methacrylate) materials based on novel highly emissive anionic molybdenum cluster complex [{Mo6I8}(OTs)6]2- (where OTs- is the p-toluenesulfonate ion). The materials were obtained by both solution and bulk copolymerisation of methyl methacrylate and (dMDAEMA)2[{Mo6I8}(OTs)6], where dMDAEMA+ is the polymerisable cation [2-(methacryloyloxy)ethyl]dimethyl-dodecylammonium. Evaluation of the resultant hybrid materials showed that one could combine the excellent photoluminescent properties of the cluster complex with the transparency and processability of PMMA.