Quote Originally Posted by gmikol View Post
I picked up a copy before the holiday, and skimmed the section that CMB referenced. It's a bit over my head, chemistry-wise. I'll have to go through it again to see if I can glean anything useful from it.

I'm hoping Charles or someone else following this thread can answer the following question for me:

In looking through one chemical supplier's catalog, I came across a number of very similarly named compounds. It's not clear to me how they differ from one another as a practical matter, what benefits/detriments the different variations have, nor how to determine which would be appropriate for this endeavor. Example:

4-DIAZODIPHENYLAMINE/FORMALDEHYDE CONDENSATE HYDROGEN SULFATE
4-DIAZODIPHENYLAMINE/FORMALDEHYDE CONDENSATE HEXAFLUOROPHOSPHATE
4-DIAZODIPHENYLAMINE SULFATE
4-DIAZODIPHENYLAMINE/FORMALDEHYDE CONDENSATE HYDROGEN SULFATE ZINC CHLORIDE COMPLEX

The first one has the same CAS# (41432-19-3) as a widely-used screen emulsion sensitizer.

--Greg
Items 1 and 2 above are the Sulfuric Acid and Fluoro-Phosphate salts of the basic diazo material. Both are condensed with formalin and if it is released, it will harden gelatin. Decomposition of the Diazonium salt in an image forming configuration will harden the gelatin imagewise. Premature release will cause overall hardening.

Three above is the Diazo salt of Sulfuric Acid with no Formaldehyde. It will not harden gelatin as there is nothing to release, but the Diazonium salt can react with amino groups in gelatin and have some effect.

I am not familiar with #4, but it looks to be similar to #1 and 2 with Zinc added. These additions help stabilize Diazonium salts which are not known for stability. They can be explosive and can release Nitrogen spontaneously and end up inactive or reactive in another fashion.

PE