Catalytically active colloids maintain non-equilibrium conditions in which
they produce and deplete chemicals and hence effectively act as sources and
sinks of molecules. While individual colloids that are symmetrically coated do
not exhibit any form of dynamical activity, the concentration fields resulting
from their chemical activity decay as 1/r and produce gradients that attract
or repel other colloids depending on their surface chemistry and ambient
variables. This results in a non-equilibrium analogue of ionic systems, but
with the remarkable novel feature of action-reaction symmetry breaking. We
study solutions of such chemically active colloids in dilute conditions when
they join up to form molecules via generalized ionic bonds, and discuss how we
can achieve structures with time dependent functionality. In particular, we
study a molecule that adopts a spontaneous oscillatory pattern of
conformations, and another that exhibits a run-and-tumble dynamics similar to
bacteria. Our study shows that catalytically active colloids could be used for
designing self-assembled structures that posses dynamical functionalities that
are determined by their prescribed 3D structures, a strategy that follows the
design principle of proteins