Luminescence polymeric systems

III. LUMINESCENT POLYMERIC SYSTEMS CONTAINING AN ISOCYANIDE LIGAND ASSEMBLED VIA M M INTERACTIONS... 

Luminescent Polymeric Systems Containing an Isocyanide Ligand 65... 

Two tungsten alkylidyne polymers [W(sC-(4-NCsH2-3,5-Me2))(0 Bu)3] (34) and [W(=C-(3-NC5H4))(0 Bu)3] (35) displayed emission at 635 and 640 nm, respectively, in the solid state at 77 K." Under similar conditions, the monomeric [W(=CR)(0 Bu)3] (R = aryl, alkyl) complexes were nonemissive. It was proposed that the [W=C-pyridine] TT-system contributed significantly to the frontier orbitals of these luminescent polymeric materials. 

The photophysics and photochemistry of bis-2-(9-anthryl)-ethyl glutamate and pivalate have been employed as a pair of models of different polymeric systems with the same luminescent chromophores.An ingenious method which has been used successfully to enhance excitation transfer in solid polymer is the introduction of intervening anthryl groups along a polymer chain... 

The present review begins with a brief description of the basic principles of luminescence [1-3], after which it deals with the fluorescence studies of polymers in solution and energy transfer in polymeric systems. Spectral and time dependent studies of polymers in the gel state are discussed later, with an emphasis on phase transition and phase separation studies. 

We now present several useful, or potentially useful, systems based on luminescent metal complexes in organic or inorganic supports. The probe molecules were chosen based on the above guidelines. Each probe is supported in some way by a second material to produce a practical device. The results presented show how metal complexes can be applied to diverse problems. These results also identify some problem areas with polymeric supports. We discuss some of our insights into the design and modeling of such systems and describe measurements that help unravel these complex systems. 

The first descriptions of heteronuclear luminescent supramolecular complexes were given by Fackler et al. in 1988 and 1989. In these studies, one gold-thallium and one gold-lead complex were reported. As in the case of the gold-silver dinuclear systems, the extended systems appeared as a result of the unidirectional polymerization of dinuclear or trinuclear units through metal-metal interactions. These were prepared by reaction of the gold precursor [PPN][Au(MTP)2] (PPN = N(PPh3)2 ... 

Principally, SSLEC cells may be constructed by inserting any electroactive and luminescent materials directly between electrodes or by their immobilization in more or less inert matrixes. The immobilization of the active material in an inert matrix exhibits several attractive features allowing the variation of the emitter concentration as well as tuning the system s properties by choosing different host materials. The highest possible emitter (polymeric materials or small molecules) concentration, however, can be achieved for the emissive layer with little amount (or even without) any host material. 

The intense and long-lived luminescence of these complexes has been utilized in the development of the oxygen sensor. Four mononuclear and dinuclear cyclometalated iridium(III) diimine complexes were immobilized in polymerized poly(ethylene glycol) ethyl ether methacrylate matrices, and the oxygen quenching on the luminescence of the films was studied. Tinear Stem-Vohner plots were obtained. Despite the difference in the luminescence energy and lifetimes of the complexes, similar Stem-Volmer slopes were observed. The size and charge of the complexes played an important role in the sensitivity of the systems. 

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