Polyelectrolyte complexes containing diazonium groups (PEC-N2) with a high ionic crosslinking rate were prepared as a precipitate by mixing the diazo-resin with polyanion solutions. The photochemical decomposition of the complexes from different polyanions was studied. It was shown that PEC-N2 exhibit high photosensitive properties. Under irradiation of UV light, the complexes which can be dissolved in ternary mixtures such as H,O-DMF-LiCl,H,O-DMF-NaSCN or H20-DMF-ZnCl2 (DMF N,N-dimethylformamide) become indissoluble since the crosslinking structure of the complexes changes from ionic to covalent.
3-Methoxydiphenylamine-4-diazonium salt (MDDS) and its diazoresin were synthesized. The photo-and thermal decomposition of salt and the resins were investigated. The results show that MDDS exhibits excellent thermostability as well as high photosensitivity. A series of diazoresins with different organic counteranions, which dissolve in common solvents and usually were chosen to manufacture the negative presensitized plate, were also synthesized The kinetics of the photo-and thermal decomposition of MDDS in ethanol is reported.
The
synthesis of soluble, conjugated poly(Zn-salphen)-alt-(p-phenyleneethynylene)s with a coilable structure
and bearing acetylated sugar substituents is described, and their
photophysical properties and conformational behavior have been investigated.
Their CD spectra confirm that these systems are chiral, and signify
ordered (helical) coiling of the polymer backbone arising from chirality
transfer from the β-d-glucopyranosyl groups. The consequences
of varying side-chain substituents as well as the extent of inter-
and intrachain [π-stacking and Zn···O(salphen)]
interactions have been studied, and comparisons with the corresponding
linear-rod and Pt-based congeners have been made. Analysis of the
effects of different solvents on these systems by UV–vis absorption,
emission, and CD spectroscopy indicates that low-polarity solvents
give a tighter, more compressed helical structure with increased CD
intensities, while coordinating solvents can perturb the folded conformation
to afford a more extended coiled structure with decreased Cotton effects.
These observations, together with variable-temperature CD experiments,
point to the flexibility and dynamic nature of the helical conformation.
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