Sack the city and have a diplo hand it back. That way there is no revolt and in reality there should not be a revolt in a freshly conquered city that is left vacant by your troops.

Sacking the enemy capital may cause them military harm but may actually economically help them as it seems the capital gets moved to a central area wich means less corruption and higher income.

I know financial chaos historically would happen but it's just a game and the poor A.I. does'nt need anymore hurting