Consider a complex with Central Metal atom M A and B are monodentate ligands . Consider a compound with formula as [M A4 B2] . Textbook and the web says there can be only 2 possible isomers of this compound . What I say is, why can't I in the first image put A on the top and bring B towards the bottom something like this . And them form these, That will give a total of 2 new ones I formed and the two old ones, 4 isomers . Why is this not possible, I mean why can't a occupy the two places ?