A metal chelate compound comprising a compound of the Formula (1) or a salt thereof:
wherein:
Het is a nitrogen containing heterocycle selected from the group consisting of Formula (2), (3), (4), (5), (6) or (7):
R is a substituent;
Y is CH
3
or COOH;
Z is a substituent,
n is 0 to 3;
p is 0 to 6;
q is 0 to 5;
r is 0 to 3; and
s is 0 to 2. Also compositions and inks, printing processes, printed material and ink-jet printer cartridges.