Diazo-type Paper

Photographic and diazo-type papers are coated with colloidal silica (720-723). In Polaroid photographic Film colloidal silica plays an essential role in the receiving layer to which the image is transferred and in which the black silver positive image is... 

This paper also can be used in a parallel way to diazo-type paper. A detailed report has been made on its use for making paper chromatogram copies in UV light [239]. 

Diazo compounds substituted with a benzoylamino group have been used for wet diazo-type copying process, which offer high sensitivity and ftermal stability. This paper will report on PAG performance of these compounds for microlithography resists. 

Full papers have appeared on the formation and reactivity of the compounds ML(CNR)2 (M = Ni, Pd, Pt L = Oz, azobenzene, olefin, diazo-fluorene, acetylene) (231-237) (see also Sections IV,D,2 and V,D). Complexes of the type Ni(olefin)(CNBu )2 have been prepared for a large range of olefins (234, 237). The isocyanide stretching frequencies have been measured and related to the electron-withdrawing properties of the olefin. Other unsaturated molecules such as imines, diazenes, ketones, nitroso compounds, and acetylenes have been similarly studied. The effect of substituent change has been found to be cumulative and an empirical relationship has been developed to predict v(NC) (237). 

The phenomena enumerated in Section 2.4 do not, of course, fully describe all the differences between chemical and electrode processes of ion radical formation. From time to time, effects are found that cannot be clearly interpreted and categorized. For instance, one paper should be mentioned. It bears the symbolic title ir- and a-Diazo Radical Cations Electronic and Molecular Structure of a Chemical Chameleon (Bally et al. 1999). In this work, diphenyldiazomethane and its 15N2, 13C, and Di0 isotopomers, as well as the CH2-CH2 bridged derivative, 5-diazo-10,ll-dihydro-5H-dibenzo[a,d]cycloheptene, were ionized via one-electron electrolytic or chemical oxidation. Both reactions were performed in the same solvent (dichloromethane). Tetra-n-butylammonium tetrafluoroborate served as the supporting salt in the electrolysis. The chemical oxidation was carried out with tris(4-bromophenyl)-or tris(2,4-dibromophenyl)ammoniumyl hexachloroantimonates. Two distinct cation radicals that corresponded to it- and a-types were observed in both types of one-electron oxidation. These electromers are depicted in Scheme 2-28 for the case of diphenyldiazomethane. 

In the first 25 years of modern carbene chemistry (since Hine s investigation, 1950), a vast number of monographs and reviews have been published on this subject In the volumes on diazo compounds of the Patai series, Ando (1978) lists 31 references of this type During the following 18 years, however, this number decreased considerably. At the borderline of these periods, the two books of Kirmse (1969, 1971) and those edited by Jones and Moss (1973) and by Moss and Jones (1975) were published, followed later by three progress reports of the same authors (Moss and Jones, 1978, 1981, 1985). There are two relatively new reviews by Minkin et al. (1989) and Frey (1991) which focus on theoretical and reactivity aspects of carbenes The review of Minkin et al. is part of a series of review papers on carbenes published in Russian Rev. Chem. (Nefedov, 1989). Selectivity of carbenes in cyclopropanation is the subject of short reviews by Moss (1980, 1989). 

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