Lars Scholten (also found as CyBear) has an 18 minute tutorial that shows how you can create animation that is triggered by the collision of objects in the scene. There are a few ways to approach this, and Lars walks through two different techniques.
This Xpresso tutorial is al about animating animations, timed on collisions of objects
One of them will cover using Xpresso: Specifically the collision node, along with the Compare, Math and Condition nodes within the Xpresso editor in Cinema 4D.
The other method is practically the same setup, using Cinema 4D’s Mograph module Dynamics as the initial trigger. There are some interesting setups in this one!