the problem im running into is that both chemicals and products have a link to experiments and compounds and file maker doesnt like this.
Presumably, your relationships are creating what looks like a circle in Manage | Database | Relationships and FileMaker cannot permit this as it would create an ambiguous set of relationships that it would not be able to properly evaluate.
The key is to realize that the boxes shown in your relationship graph are not actual tables, they are Table Occurrences. You can create additional table occurrences that refer to the same table and then you can set up the needed relationships.
Here's a a thread on table occurrences: Tutorial: What are Table Occurrences?
And here's a thread on "anchor buoy" that you may also find helpful: http://sixfriedrice.com/wp/six-fried-rice-methodology-part-2-anchor-buoy-and-data-structures/
Thanx, this was really helpfull