Synthesis and polymerization of coupled compounds of 1,11‐dodecadiyne

Nezu, S.; Walsh, Steven P.; Meille, Stefano Valdo; Yoshida, Masatoshi; Lando, J. B.

doi:10.1002/pola.1995.080330611

Cited by 3 publications

(1 citation statement)

References 6 publications

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“…The appearance of the CtC stretching band around 2160 cm -1 for the self-assembled nanofibers from 2 indicates unsymmetric packing of the molecules within the nanofibers since in general, no such band absorption is observed for symmetric diacetylenic molecules. 14 After irradiation, a reduction in intensity of the CtC stretch-ing band (73% in absorption spectra) and the appearance of the FT-IR shoulder for CdC double bonds (1725-1740 cm -1 as shown in Figure 5) both support the proposed polymerization of 2 within the nanofibers.…”

Section: Resultsmentioning

confidence: 58%

Polymerization in Nanometer-Sized Fibers: Molecular Packing Order and Polymerizability

et al. 2000

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The bolaform 1-glucosamide 1 and its deacetylated derivative 2 (N,N‘-bis(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)deca-4,6-diyne-1,10-dicarboxamide and N,N‘-bis(β-d-glucopyranosyl)deca-4,6-diyne-1,10-dicarboxamide, respectively) have been synthesized and their self-assembled structures investigated. The hydrophobic peracetylated derivative 1 formed an organogel from solution in boiling ethyl acetate/n-hexane mixtures on cooling to room temperature. In contrast, 2 produced fibrous assemblies from aqueous solution on addition of THF via vapor diffusion. Energy filtering transmission electron microscopy (EF-TEM) revealed the formation of nanometer-sized fibers (nanofibers) with widths of between 6 and 20 nm and more than 50 nm for 1 and 2, respectively. The amide and sugar hydroxyl groups in 2 allow formation of stronger, multiple hydrogen bond networks in the nanofiber than for 1. Powder X-ray diffraction studies revealed that fibers derived from 2 displayed a higher molecular packing order than those from 1. Exposure of a dispersion of either nanofiber to UV light resulted in the appearance of a red coloration. While the UV-irradiated nanofibers of 1 were readily soluble in CHCl3, those of 2 required peracetylation to allow dissolution. Subsequent gel permeation chromatography for the UV-irradiated nanofibers displayed peak-top molecular weights corresponding to 13-mer and 64-mer for 1 and 2, respectively. On the basis of EF-TEM observation, no significant morphological changes in the fibers were found after UV-initiated polymerization. On the basis of these findings, we suggest that the polymerization proceeds efficiently within the nanofiber morphologies with higher molecular packing order leading to a higher degree of polymerization to give π-conjugated polymer chains.

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Section: Resultsmentioning

confidence: 58%