If you were not receiving maintenance, then I think it is very unlikely you would have a claim. The order would normally dismiss all claims.
If he had a pension, the children may be able to benefit from that. If you received maintenance, the trustees may view a claim with some sympathy.
When my ex died, his estate was shared between the children and a "friend". It was shocking to see how little was left from the divorce settlement. Nothing I could do about it though. I am just glad most of what was left went to the children.