Well this is where opinions very so I will give you mine.
First what is your incentive for telling the children and you need to be honest with yourself?
Second this is absolutely not going to change the outcome.
Third you better make sure your side of the street is/was impeccable.
In my situation my children were young so I didn't want them thinking it was moms fault because we divorced. Truth be told it was not because I was not the perfect husband.
Now having said that, when they are older and ask me questions I will not lie to them including my part in breakdown of the marriage.