Author Topic: Litharge....which oxide is it?  (Read 2430 times)

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Bond_DoubleBond

  • Guest
Litharge....which oxide is it?
« on: October 28, 2004, 08:14:00 AM »
Swim has been considering trying the lead acetate + phenylacetic acid -> p2p reaction, but is a little confused.  In xtaldoc's post

Post 193343 (missing)

(xtaldoc: "RE: Has anyone tried the  PAA + Pb acetate synth?", Chemistry Discourse)
and rhodium's repost

Post 225635

(Rhodium: "PAA -> P2P using lead acetate", Methods Discourse)
, it is stated that litharge (PbO2) is used with glacial acetic acid to produce the needed lead acetate.  After searching, swim's findings dictate that "litharge" is commonly PbO, not PbO2.

So swim's question is, which lead oxide (or both possibly) is appropriate for this reaction?

Comments appreciated.

[edit]
Another question, the post also states, So, the first modification was to run it under a partial vacuum (5" Hg suction on a standard gauge).   Is he refering to an internal reaction vessel pressure of 5" Hg or ~25" Hg?

Organikum

  • Guest
Litharge is lead-monoxide - PbO.
« Reply #1 on: October 28, 2004, 01:36:00 PM »
Litharge is lead-monoxide - PbO.
Lead acetate is actually lead di-acetate - Pb(CH3COO)2.

Nevertheless reacting litharge with GAA will produce lead (di)-acetate as deserved, PbO2 will yield lead-(II)-acetate too.

It should be possible to run the reaction with iron-(II)-acetate instead of lead. Iron + acetic acid with a concentration of less than 60% yields iron-(II)-acetate, black iron oxide as used as cement/concrete-pigment should also work (280-300°C reaction temperature).

The US way(s) for naming units of vacuum are inconsistent and therefor I see no way to tell what xtaldoc meant with 5" vacuum. You can see it from both sides thats it.

Did you get the chinese patent working? (styrene/alc/sulfur)
Or did somebody else get it working?