Aliphatic polymers luminescence

Luminescent copper- and silver-containing coordination polymers were prepared by Harvey and collaborators using 1,8-diisocyano-p-menthane (dmb) as the coordinating unit.29,30 This aliphatic diisonitrile ligand can adopt two conformations as depicted in Figure 6. 

Many problems in the physics and chemistry of polymers have been investigated by means of fluorescence techniques. Within the scope of this book, it is merely possible to point out the high versatility of these techniques rather than to discuss the innumerable publications. Among the features of luminescence that account for the variety of its applications is the fact that emission spectra can be recorded at extremely low chromophore concentrations. Thus, a polymer may be labeled with such a small amount of luminophore that the labeling does not perturb the properties of the system. As regards linear polymers in solution, it is possible to derive information on the conformational state and the behavior of the macromolecules. This concerns such topics as the interpenetration of polymer chains, the microheterogeneity of polymer solutions, conformational transitions of polymer chains, and the structures of polymer associates. Relevant work has been reviewed by Morawetz [59]. Here, only one typical example is described, which concerns the kinetics of HCl transfer from aromatic amino moieties to much more basic aliphatic amino groups attached to discrete macromolecules, in this case poly(methyl methacrylate)s (see Scheme 1.5). 

B.A. San Jose, S. Matsushita, K. Akagi, Lyotropic chiral nematic liquid crystalline aliphatic conjugated polymers based on di-substituted polyacetylene derivatives that exhibit high dissymmetry factors in circularly polarized luminescence. J. Am. Chem. Soc. 134, 19795-19807 (2012)... 

A detailed evaluation of the structural parameters affecting the photophysical properties was performed for the didodecyloxy-substituted quinquephenyl rigid-flexible polyethers 60. More particularly, the odd-even effect was observed for dilute polymeric solutions by means of steady-state and time-resolved fluorescence anisotropy. The different orientations of the quinquephenyl chromophores, and subsequently of their luminescent dipoles, concerning the polymers with an odd number of methylene units x=7, 9, 11) and those with an even (x = 8, 10, 12) one, were found responsible for the observed strong deviations in frozen and dilute solutions, where the flexible aliphatic chains are forced to adopt a nearly sta ered, lower energy conformation. 

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