diethyl zinc
An organometallic compound (Zn(C.,H).,), that is
readily volatile (B.P. 123° C. at one
atmosphere). It has been proposed as a vapor-phase
deacidifying agent, and gives promise of being
effective; it leaves an alkaline reserve of zinc
oxide in the paper, which not only protects
against acid but is an effective fungicide as
well. Treatment must be carried out in the absence
of air or moisture, as diethyl zinc ignites on
contact with air and explodes on contact with
moisture. This requires that the books be
absolutely dry before treatment; therefore they
must be treated with the gas in a vacuum chamber
and the excess diethyl zinc must be removed or
neutralized before the chamber is opened.
Treatment with diethyl zinc leaves the paper with
a pH of approximately 7.5 and does not appear to
have any adverse effect on leather or other book
materials.