Dynamic combinatorial chemistry (DCC); also known as constitutional dynamic chemistry (CDC) is a method to the generation of new molecules formed by reversible reaction of simple building blocks under thermodynamic control.[3][4] The library[further explanation needed] of these reversibly interconverting building blocks is called a dynamic combinatorial library (DCL).[5][6] All constituents in a DCL are in equilibrium, and their distribution is determined by their thermodynamic stability within the DCL.