The present invention provides an IR-absorbing naphthalocyanine dye of
formula (I): ##STR00001## wherein M is selected from
Si(A.sup.1)(A.sup.2), Ge(A.sup.1)(A.sup.2), Ga(A.sup.1), Mg, Al(A.sup.1),
TiO, Ti(A.sup.1)(A.sup.2), ZrO, Zr(A.sup.1)(A.sup.2), Vo,
V(A.sup.1)(A.sup.2), Mn, Mn(A.sup.1), Fe, Fe(A.sup.1), Co, Ni, Cu, Zn,
Sn, Sn(A.sup.1)(A.sup.2), Pb, Pb(A.sup.1)(A.sup.2), Pd and Pt; A.sup.1
and A.sup.2 are axial ligands, which may be the same or different, and
are selected from --OH, halogen, --OR.sup.3, a hydrophilic ligand and/or
a ligand suitable for reducing cofacial interactions; R.sup.1 and R.sup.2
are selected from H or C.sub.1-12alkoxy; R.sup.3 is selected from
C.sub.1-12alkyl, C.sub.5-12aryl, C.sub.5-12arylalkyl or
Si(R.sup.x)(R.sup.y)(R.sup.z); and R.sup.x, R.sup.y and R.sup.z may be
the same or different and are selected from C.sub.1-12alkyl,
C.sub.5-12aryl, C.sub.5-12arylalkyl, C.sub.1-12 alkoxy, C.sub.5-12aryloxy
or C.sub.5-12arylalkoxy; W is a hydrophilic group; n1 is 0, 1, 2 or 3; n2
is 0, 1, 2 or 3; n3 is 0, 1, 2 or 3; n4 is 0, 1, 2 or 3; provided that at
least one of n1, n2, n3 or n4 is greater than 0. Dyes of this type are
especially suitable for use in netpage and Hyperlabel systems.
