amazingnature
Easy to check: click on the forum name, in this case "Ask a Question" and scroll through the recent posts. Which I just did, and don't see a Q about Tree of Heaven. So go ahead and ask again.
Here are some anticipatory answers: Tree of Heaven, Ailanthus altissima, native to China and a fast growing invasive species in the US. A royal PITA for anyone who has them growing nearby. Smells sort of like rancid peanut butter, sprouts quickly and grows fast. However, it has very soft wood so is easy to cut.
It is known to produce allopathic chemicals which inhibit or prevent growth of some plants. Scattered sprouts and seedlings are best dug out but if any part of the roots remain they will re-sprout. If you want to know about what poisons kill it, someone else will have to answer.