Photoreactions diazides

The photoreactions of azides can in most cases be rationalized in terms of the initial formation of nitrenes which then undergo rearrangement, insertion or addition reactions. Nitrene rearrangement is thought to be responsible for the conversion of the a-azido ethers (81) into the imino ethers (82), and the first silanediimine (83) to be described has been prepared in a similar fashion from the diazide (84) as shown in Scheme 4. Intramolecular nitrene addition to suitably aligned nitrogen-nitrogen double bonds has been employed in the synthesis of triaziridines. 

V.V. Ershov, G.A. Nikiforov, and C.R.H.I. de Jonge, Quinone Diazides, Elsevier, Amsterdam (1981). A. Reiser, Photoreactive Polymers The Science and Technology of Resists, p. 187, John Wiley Sons, Hohoken, NJ (1989) R. Dammel, Diazonaphthoquinone based Resists, pp. 13 15, SPIE Press, Belhngham, WA (1993). 

Positive polyimide resists have also been developed. One example starts from a solnble polymer [60] with a formulation analogons to a novolac positive resist o-naphthoquinone diazide was used as a photoreactant linked to the polymer (Figure 6.25). 

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