Poly diacetylene

LB films of CO-tricosenoic acid, CH2=CH—(CH2)2qCOOH, have been studied as electron photoresists (26—28). A resolution better than 50 nm could be achieved. Diacetylenic fatty acids have been polymerized to yield the corresponding poly (diacetylene) derivatives that have interesting third-order nonlinear optical properties (29). 

G. Wegner, Recent Progress in the Chemistry and Physics of Poly(diacetylenes), in W.E.Hatfield(ed-), Molecular Metals, Plenum, New York, 1979. 

Orchard B, Tripathy S (1986) Molecular-structure and electronic property modification of poly(diacetylenes). Macromolecules 19 1844—1850... 

Poly(acetylenes) [16], poly(diacetylenes) [17], poly(phenylenes) [18] and poly(phenylenevinylenes) [19] have been proposed as main chains. The new molecular design that has to be developed now concerns the question of where to place the open-shell centres on the pendents in the side chains of the polymers (Iwamura, 1987, 1988 Iwamura and Murata, 1989 Murata et a/., 1987 Ovchinnikov, 1978 Tyutyulkov et al., 1985 Yamaguchi et al., 1987). 

Biosensors based on poly(diacetylene)s have also been investigated by other groups [51-54]. These have proved successful in detecting biologically relevant agents such as the influenza virus and cholera toxin. 

Fig.l General schematic structures of poly(arylene ethynylene)s (PAEs), poly(arylene)s (PAs), poly( arylene vinylene)s (PAVs), and poly (diacetylene) s (PDAs)... 

Pan JJ, Charych D. Molecular recognition and colorimetric detection of cholera toxin by poly (diacetylene) hposomes incorporating GMl ganglioside. Langmuir 1997 13 1365-1367. 

The ideal systems to test this conjecture are single-crystalline poly-diacetylenes (PDAs), notably perfect PDA chains embedded in a crystalline lattice [15]. Employing the electroreflection method, Weiser and Mbller [136] analyzed the... 

Aqueous dispersions of polymerizable lipids and surfactants can be polymerized by UV irradiation (Fig. 18). In the case of diacetylenic lipids the transition from monomeric to polymeric bilayers can be observed visually and spectroscopically. This was first discussed by Hub, 9) and Chapman 20). As in monomolecular layers (3.2.2) short irradiation brings about the blue conformation of the poly(diacetylene) chain. In contrast, upon prolonged irradiation or upon heating blue vesicles above the phase transition temperature of the monomeric hydrated lipid the red form of the polymer is formed 23,120). The visible spectra of the red form in monolayers and liposomes are qualitatively identical (Fig. 19). 

An alternative view of the polysilane structure is depicted using the worm-like model as proposed for poly(diacetylene)s59, where the linear chain has a large number of small twists without sharp twists playing a special role60-62. In this model, a Gaussian distribution of site energies and/or exchange interactions and the coherence of the excitation is terminated by any of the numerous usual random deviations from perfect symmetry. 

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. 

Poly(diacetylenes) also exhibit large %(3) values in resonant modes. Optical phase conjugation (DFWM) was demonstrated at 532 nm in solutions of a soluble diacetylene polymer, with %(3) 5 x 10-12 esu. 136) No... 

X(3) values for several azo dyes at 633 nm and for a squarylium dye at 7 9 9 nm dispersed in Poly(methylmethacrylate) glasses, and compare the results (obtained by electrooptic methods) to those for a model poly(thiophene) and a poly(diacetylene).(147)... 

Fig. 32 (a) Topochemical polymerization mechanism for a typical diacetylene monomer, (b) Crystal structure of a typical poly diacetylene... 

Figure 4.10 UV-induced topochemical polymerization, (a) UV spectra of compounds F-l did not show any indication of poly(diacetylene) formation, (b, c) Macromonomers A-D were successfully converted into poly(diacetylene)s. (d) The reactivity toward topochemical polymerization was related to the total number of hydrogen bonds, (e) Upon addition of HFIP to a sample solution in DCM after UV irradiation, helical fibrillar...

Figure 4.11 Schematic representation of the conversion of stranded poly(diacetylene)s with a multiple-helical quaternary the supramolecular polymers into conjugated polymers under structure in the case of A. retention of the hierarchical structure, leading to four-... 

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