Can payment of mahr be made conditional to staying married for more than a year?

Salam, I was born and raised in America so it is a bit difficult to marry a woman and get to know them beforehand while still keeping it halal. Like being able to talk to her one on one and etc. I wanted to see is it permissible to have my Nikkah and in the contract for mehr I can say I will pay it if and only if for example stay together longer than a year, but if we don’t seem to get along together then we can break off basically divorce and I don’t owe her mehr? Because personally I want to marry someone who’s personality goes well with mine so i would prefer we become friends and than marry almost like a dating stage in the western area in America. However at the same time i want to keep it 100% halal so I thought would this be acceptable. Also I know i could talk to her when someone is present with her but I personally think to get the true personality of them it’s Best when they’re alone.