I have White 2 and my brother has Explorers of Darkness. Can we interact with each other with said games?
No, the Pokemon Mystery Dungeon Games cannot interact with the main series games like Black/White 2.
I would mention however that some of the Pokemon Ranger series can. Pokemon Ranger Shadows of Almia for instance can transfer Riolu, Darkrai and Manaphy. Pokemon Guardian Signs can transfer an event obtained Deoxys.