Poly polydiacetylenes

The polymerization of the butadiene monomers (3,4) can also be followed spectroscopically by the disappearance of the strong absorption of the monomers at 260 nm, whereas the absorption of the resulting poly-1,4-trans(butadiene)s is too small to be observed in a single monolayer. The polymers from the butadiene and methacryloyl lipids are probably better model membrane systems, because the polymer chains are still mobile and not excessively rigid as the polydiacetylenes. 

Lee NY, Jung YK, Park HG. On-chip colorimetric biosensor based on polydiacetylene (PDA) embedded in photopolymerized poly(ethylene glycol) diacrylate (PEG-DA) hydrogel. 

A growing number of reports are appearxng concerning %<3) of materials as determined by THG experiments. Among organics a variety of poly(diacetylenes), e. g., 4-BCMU (4-butoxycarbonylmethylurethane polydiacetylene) (15,109) have been studied as pure materials and as LB films, 110) Crystalline films of poly(4-BCMU) in the red form, were found to have higher %<3) than amorphous films, attributed to the orientational effect of crystallization.(109) The blue form also has been studied. 111) Maximum values of %<3) reported to date are 1 x 10 10 esu at 1.3 l. Poly (phenylacetylene) THG at 1.06 lhas recently been measured. 111) The 2- and 3-photon resonance enhanced value of %<3) determined is 7 x 10 12 esu. 

The synthesis and characterization of polyacetylene (PA) provided new incentive for understanding 7r-electronic spectra, electron-phonon interactions and electronic correlations[l, 2, 14]. The electrical conductivity of chemically doped PA rivals that of metals. Families in Fig. 2 such as polydiacetylenes (PDAs), poly thiophenes (PTs), cr-conjugated polysilane (PSs) and polyparaphenylene vinylene (PPVs), among... 

The area of molecular nonlinear optics has been rejuvenated by efforts to investigate three-dimensional multipolar systems, functionalized polymers as optoelectronic materials, near infrared optical parametric oscillators and related aspects.71 There have been some advances in chromophore design for second-order nonlinear optical materials 72 these include onedimensional CT molecules, octopolar compounds and organometallics. Some of the polydiacetylenes and poly(/>-phenylenevinylene)s appear to possess the required properties for use as third-order nonlinear optical materials for photonic switching.73... 

Poly diacetylenes. The polydiacetylenes (PDA s) are unique among highly conducting polymers discovered in the past years in that they can be obtained as highly perfect macroscopic single crystals.68 Upon solid-state polymerization of... 

Conjugated polymers satisfy these requirements and have thus emerged as the most widely studied materials for their susceptability. Some of the examples of conjugated polymers, that have been studied for their third order NLO properties, are polydiacetylenes, poly-p-phenylenevinylenes and polythiophenes. However, CVD has only been used in the case of poly-p-phenylenevinylenes (PPV) [section 3.4], although values have not been reported. An excellent review of third order nonlinear optical properties of PPV in general, can be found in literature. Recently, McElvain et al. ° reported the values of CVD polyazomethines to be... 

Figure 3.26. Polydiacetylene mesomers (a) and (b) with different energetic conformation. A single crystal of poly(2,4-hexadiyne-l,6-diol-bis-p-toluene-sulfonate) shows strong TP resonances at about 2.7 eV and 2.1 eV, and a weaker TP state that is centered at 1.8 eV when irradiated with a 2 1 ps Ti sapphire laser [405].

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