Pyrene tagging

Figure 5. Fluorescence spectra of pyrene tagged novolac and free pyrene butyric acid (PBA) in diglyme. Spectra are labeled with percent of monomer units tagged. The pyrene concentration in solution is 1 x 10 bM, except in the inset where different pyrene concentrations are compared along with the spectra of a film containing the tagged polymer.

Figure 6. Comparison of excimer intensity for free and tagged pyrene in novolac films. Film composition ( ) free pyrene in novolac (A) pyrene tagged novolac (o) 19.6 mol% pyrene tagged novolac mixed with untagged novolac. The inset is an expansion of the graph for low pyrene concentrations.

Figure 1. Intramolecular excimer to monomer emission intensity ratio as a function of the molar ratio of poly carboxylic acid) to PEG for Py-PEG-Py of weight-average molecular weights 4800 and 9200. All data are nomwlized by the Id/Im value for a 1% pyrene-tagged PEG solution with no polyacid added.

Ruiz-Botella S, Peris E. Phenylene and biphenylene-bridged bis-imidazolylidenes of palladium. Influence of the presence of pyrene tag s on the catalytic activity of the complexes. Organometallics. 2014 33 5509-5516. 

Pvrene Fluorescence Spectra. Solutions of the tagged polymers In diglyme were prepared to have 1 x 10 M pyrene, based on the tagging levels mentioned in the previous section. This resulted in polymer concentrations of 2.33 x 10, 8.47 x 10, 3.65 x 10, 1.99 x... 

Oyama et al. [23] utilized fluorescence spectroscopy to study how the molar masses of both PAA and PEO affect complexation. Actually, they used the exci-mer formation between the pyrene groups attached to the chain ends of PEO as a molecular probe. The molecular weights of PAA used were 1850, 4600 and 890,000, and those of PEO were 4800 and 9200. The latter are much lower than the PEO molecular weight in the work of Bednar et al. [19]. In order to monitor both intramolecular and infermolecular excimer formation, it was necessary to distinguish the two types of excimers clearly, so Oyama et al. used two kinds of solutions. One contained 99% of untagged PEO and only 1% PEO, where PEO refers to PEO whose chain ends are tagged by pyrene. In this solution, PEO is believed to behave Hke an individual PEO chain, which provides only intramolecular excimer. The other contained fully tagged PEO, which provides both intramolecular and intermolecular excimers. 

Sample Preparation. The homologous series of the even n-alkanoic acids, abbreviated as C10 through C were used as the adsorbates. Hexadecane (HD), which is nonpolar and has a rather high boiling point, was used as the solvent. Microscope glass slides and evaporated aluminum (on silicon wafers) were used as the substrates. Pyrene end-tagged hexadecanoic acid (Py-C16) was used as the fluorescence probe. 

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