Gently, you need to be more flexible and realistic about what you want. You can provide for your children, but you cannot control the minutiae of what happens after you are gone.
Your DH has a claim to the marital home and assets, whether you divorce him or not. You cannot leave the house entirely to your DC, though - as PPs have said - you may be able to leave them your share of it. You will not be able to prevent your DH from using his share of the house as he sees fit, which includes leaving it to future children, if he chooses. His share is his house, not yours - it isn't within your power to leave him a lifetime interest - it is his property, not yours.
You very naturally want to imagine your DC staying in the family home, but be realistic about this. Will your DC want to share it with their father as they get older, especially if he remarries? You mention having an investment property. Leaving this to your DC, so they can sell it to buy their own place, may be a better option (though your DH is likely to have a claim to it too, as a marital asset). If you have a pension with a surviving spouse benefit, and you divorce your DH, he will not benefit from it. You may not care about this now, but do you want him to be potentially financially dependent on your DC? And, if they do share the house, don't you want him to have the funds to maintain it? It might be better for all concerned if he receives the pension.
Instead of having very fixed ideas about what you want, talk to a solicitor and financial advisor about how you can maximise the assets you leave your DC.