P-Azidocinnamate

Photocross I inking of poly(vinyl-p-azidocinnamate) (XIII) is reported to involve competitive photodimerization of cinnamoyl groups to cyclobutenes along with the dominant nitrene reactions of insertion and radical abstraction. The reaction can be triplet-sensitized (19). 

Triplet States. The measurement of the Sq- T-i transition energy was succeeded in the case of ethyl p-azidocinnamate, too(Fig.5(b)). 

Figure 7. Comparison of the calculated values with the experimental ones on the electronic transition energies and oscillator strengths of the p-azidocinnamate (ethyl p-azidocinnamate in n-hexane)...

Abstract Although aromatic azides are believed not to emit phosphorescence, 2,4,6-tribromophenylazide was found to phosphoresce in EPA at 77°K, and the peak of the spectrum coincides with the tail of the absorption spectrum of its concentrated solution in ethyl iodide. The measurements of the So4Ti absorption spectra in ethyl iodide with vibrational structures were also succeeded in the cases of ethyl p-azi-dobenzoate and ethyl p-azidocinnamate. The experimantal values coincided with the )3 transition energies estimated by SCF MO Cl... 

Aromatic azides are stable photosensitive compounds and some of them mixed in cyclized rubber are practically used as photosensitive resines.(jJ Such photosensitive polymers as poly(vinyl p-azidobenzo-ate)(2) and poly(vinyl p-azidocinnamate)(3) are also investigated. These photosensitive resines are known to be spectrally sensitized by triplet sensitizersQ,2,3). But the energies E(T1) of the lowest triplet states T-) of aromatic azides have not been known, because these compounds emit no phosphorescence(4) and the trials on the measurement of their S0 >Ti absorptions are failed(4,5). 

Ethyl p-azidobenzoate and ethyl p-azidocinnamate were synthesized from p-amino derivatives in a similar manner. 

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