since the traditional co-additives for the
copper fixation, e.g. chromium species [12], are environmentally
unacceptable. The mode of action and binding of copper(II) compounds
onto wood is not clear-cut, because no lignin isolation from
plant tissues, without the resulting changes in its structure, was to
our knowledge successfully done. Therefore, the lignin model compounds
represent a suitable opportunity for copper to wood binding
studies [7,13]. The basic lignin model compounds are mostly of
three types, namely guaiacyl, syringy and p-hydroxyphenyl [2].
The initial building blocks for the guaiacyl models (vanillin, vanillic
acid and ferulic acid) is 4-hydroxy-3-methoxybenzyl moiety
(Scheme 1). Several molecular structures of copper(II) complexes
with vanillin [14–21] and vanillic acid anions [21–23] are described,
but so far none with ferulic acid, for which only some preliminary
data were reported [