How to Define Interaction Sites???

Hello Everybody,

I am running the Dynamics of a system which has two molecules. (attached JPG)

These molecules have CN group at their ends. Every CN group has a dipole moment.

So there is a possible interation between two end groups of different molecules.

So these two ends will try to stick together is the temperature is low.

My problem is that I am not able to define these interactions during the dynamics.

Can somebody tell me how to define this kind of interations(dipole dipole interaction)?

Anant