For these kinds of things I like to create separate objects for each purpose and bundle these under a master controller object.
Make an empty game object and call it something like COIN MASTER. Bring an animated coin mesh into the project, label it something like COIN MESH, and make it a child of the master object. Then create an empty game object, call it PARTICLES, add a particles component to it, tweak till the effect looks good and put this object as a child of the master game object. Have the coin animating and then when the moving object hits the master object collider an FSM on the master object would deactivate the spinning coin and activate the particles object which would let off a pulse of particle sprites. Once the object is finished with you could either destroy it or deactivate it and move it off screen
Once I had this was working I would make the master object a prefab.
Chur,
C